bluuebunny/crossref_metadata_2025 huggingface dataset:
Histone variants in archaea and the evolution of combinatorial chromatin complexity
Authors: Stevens Kathryn M , Swadling Jacob B , Hocher Antoine , Bang Corinna , Gribaldo Simonetta , Schmitz Ruth A , Warnecke Tobias
Published: April 2020

Nucleosomes in eukaryotes act as platforms for the dynamic integration of epigenetic information. Post-translational modifications are reversibly added or removed and core histones exchanged for paralogous variants, in concert with changing demands on transcription and genome accessibility. Histones are also common in archaea. Their role in genome regulation, however, and the capacity of individual paralogs to assemble into histone-DNA complexes with distinct properties remain poorly understood. Here, we combine structural modelling with phylogenetic analysis to shed light on archaeal histone paralogs, their evolutionary history and capacity to generate complex combinatorial chromatin states through hetero-oligomeric assembly. Focusing on the human commensal Methanosphaera stadtmanae as a model archaeal system, we show that the heteromeric complexes that can be assembled from its seven histone paralogs vary substantially in DNA binding affinity and tetramer stability, occupying a large but densely populated chromatin state space. Using molecular dynamics simulations, we go on to identify unique paralogs in M. stadtmanae and Methanobrevibacter smithii that are characterized by unstable dimer:dimer interfaces. We propose that these paralogs act as capstones that prevent stable tetramer formation and extension into longer oligomers characteristic of model archaeal histones. Importantly, we provide evidence from phylogeny and genome architecture that these capstones, as well as other paralogs in the Methanobacteriales, have been maintained for hundreds of millions of years following ancient duplication events. Taken together, our findings indicate that at least some archaeal histone paralogs have evolved to play distinct and conserved functional roles, reminiscent of eukaryotic histone variants. We conclude that combinatorially complex histone-based chromatin is not restricted to eukaryotes and likely predates their emergence.
Intragenic conflict in phylogenomic datasets
Authors: Smith Stephen A. , Walker-Hale Nathanael , Walker Joseph F.
Published: April 2020

Most phylogenetic analyses assume that a single evolutionary history underlies one gene. However, both biological processes and errors in dataset assembly can violate this assumption causing intragenic conflict. The extent to which this conflict is present in empirical datasets is not well documented. However, if common, it would have far-reaching implications for phylogenetic analyses. Here, we examined several large phylogenomic datasets from diverse taxa using a fast and simple method to identify well supported intragenic conflict. We found conflict to be highly variable between datasets, from 1% to more than 92% of genes investigated. To better characterize patterns of conflict, we analyzed four genes with no obvious data assembly errors in more detail. Analyses on simulated data highlighted that alignment error may be one major source of conflict. Whether as part of data analysis pipelines or in order to explore potential biologically compelling intragenic processes, analyses of within gene signal should become common. The method presented here provides a relatively fast means for identifying conflicts that is agnostic to the generating process. Datasets identified with high intragenic conflict may either have significant errors in dataset assembly or represent conflict generated by biological processes. Conflicts that are the result of error should be identified and discarded or corrected. For those conflicts that are the result of biological processes, these analyses contribute to the growing consensus that, similar to genomes, genes themselves may exhibit multiple conflicting evolutionary histories across the tree of life.
Cryo-EM structures reveal transcription initiation steps by yeast mitochondrial RNA polymerase
Authors: De Wijngaert Brent , Sultana Shemaila , Dharia Chhaya , Vanbuel Hans , Shen Jiayu , Vasilchuk Daniel , Martinez Sergio E. , Kandiah Eaazhisai , Patel Smita S. , Das Kalyan
Published: April 2020

Cryo-EM structures of transcription pre-initiation complex (PIC) and initiation complex (IC) of yeast mitochondrial RNA polymerase show fully resolved transcription bubbles and explain promoter melting, template alignment, DNA scrunching, transition into elongation, and abortive synthesis. Promoter melting initiates in PIC with MTF1 trapping the −4 to −2 non-template (NT) bases in its NT-groove. Transition to IC is marked by a large-scale movement that aligns the template with RNA at the active site. RNA synthesis scrunches the NT strand into an NT-loop, which interacts with centrally positioned MTF1 C-tail. Steric clashes of the C-tail with RNA:DNA and NT-loop, and dynamic scrunching-unscrunching of DNA explain abortive synthesis and transition into elongation. Capturing the catalytically active IC-state with UTPαS poised for incorporation enables modeling toxicity of antiviral nucleosides/nucleotides.
Zirconium(IV)-IMAC for phosphopeptide enrichment in phosphoproteomics
Authors: Diez Ignacio Arribas , Govender Ireshyn , Naicker Previn , Stoychev Stoyan , Jordaan Justin , Jensen Ole N.
Published: April 2020

Phosphopeptide enrichment is an essential step in large-scale, quantitative phosphoproteomics studies by mass spectrometry. Several phosphopeptide affinity enrichment techniques exist, such as Immobilized Metal ion Affinity Chromatography (IMAC) and Metal Oxide Affinity Chromatography (MOAC). We compared Zirconium (IV) IMAC (Zr-IMAC) magnetic microparticles to more commonly used Titanium (IV) IMAC (Ti-IMAC) and TiO2magnetic microparticles for phosphopeptide enrichment from simple and complex protein samples prior phosphopeptide sequencing and characterization by mass spectrometry (LC-MS/MS). We optimized sample-loading conditions to increase phosphopeptide recovery for Zr-IMAC, Ti-IMAC and TiO2based workflows. The performance of Zr-IMAC was enhanced by 19-22% to recover up to 5173 phosphopeptides from 200 µg of protein extract from HepG2/C3A cells, making Zr-IMAC the preferred method for phosphopeptide enrichment in this study. Ti-IMAC and TiO2performance were also optimized to improve phosphopeptide numbers by 28% and 35%, respectively. Furthermore, Zr-IMAC based phosphoproteomics in the magnetic microsphere format identified 23% more phosphopeptides than HPLC-based Fe(III)-IMAC for same sample amount (200 µg), thereby adding 37% more uniquely identified phosphopeptides. We conclude that Zr-IMAC improves phosphoproteome coverage and recommend that this affinity enrichment method should be more widely used in biological and biomedical studies of cell signalling and in the search for disease-biomarkers.
Reflux of Endoplasmic Reticulum proteins to the cytosol yields inactivation of tumor suppressors
Authors: Sicari Daria , Pineau Raphael , Reste Pierre-Jean Le , Negroni Luc , Chat Sophie , Mohtar Aiman , Thomas Daniel , Gillet Reynald , Hupp M. Ted , Chevet Eric , Igbaria Aeid
Published: April 2020

In the past decades many studies reported Endoplasmic Reticulum (ER) resident proteins to localize to the cytosol but the mechanisms by which this occurs and whether these proteins exert cytosolic functions remain unknown. We found that select ER luminal proteins accumulate in the cytosol of glioblastoma cells isolated from mouse and human tumors. In cultured cells ER protein reflux to the cytosol occurs upon proteostasis perturbation. As such we investigated whether refluxed proteins gain new functions in the cytosol thus providing advantage to tumor cells. Using the ER luminal protein AGR2 as a model, we showed that it is refluxed to the cytosol where it binds and inhibits the tumor suppressor p53. We named this phenomenon ER to Cytosol Signaling (ERCYS) as an ER surveillance mechanism conserved in Eukaryotes to relieve the ER from its contents upon stress and to provide selective advantage to tumor cells through gain-of-cytosolic functions.
Water and nutrient cycling regulation functions in forest ecosystems: a comparison between native forests and exotic fast-growing tree species plantations in tropical highlands
Authors: León-Peláez Juan Diego , Villegas Juan Camilo , Amador-Pérez Jorge Alejandro
Published: April 2020

An improved understanding of ecosystem functions is increasingly needed as ecosystem management moves towards optimizing their capacity to provide services to society. Such a task requires the characterization of ecosystem functions in strategic systems such as tropical mountain forests, which are also subject to pressure due to both global and local environmental changes. In particular, transformation of native forests into pastures or agriculture, has been regarded as the type of transformation with the largest effects in ecosystem regulating and provision functions. However, the effects of other transformations such as those associated with replacement of native with planted forests, have been less studied. To evaluate the effect of forest type on key-ecosystem functions related to water resources, we studied the dynamics of rainfall partitioning and nutrient circulation on a suite of representative forest types in neotropical mountain systems: two plantations of exotic fast-growing species and two types of native forests. Our results illustrate that, when considered in a per-basal unit area, water transmission to the forest floor is significantly higher in both native forests. Similarly, native forests are more effective on circulating nutrients on the ecosystem as they are better adapted to oligotrophic soils such as those occurring in tropical mountains. These results suggest that the replacement of native forests with exotic tree plantations can potentially impact hydrological regulation and the nutrient cycling in these high Andean lands, affecting both directly and indirectly the capacity of ecosystems to produce services to society.
An indispensable role for dynamin-related protein 1 (DRP1) in adipogenesis
Authors: Reddy Mooli Raja Gopal , Mukhi Dhanunjay , Chen Zhonghe , Buckner Nia , Ramakrishnan Sadeesh K.
Published: April 2020

Emerging evidence indicates that proper mitochondrial dynamics is critical for adipocyte differentiation and functional thermogenic capacity. We found that mitochondrial fission protein dynamin-related protein 1 (DRP1) is highly expressed in brown adipose tissue compared to white adipose tissue and their levels increase during brown adipocyte differentiation. Our results reveal that the inhibition of DRP1 using Mdivi-1 mitigates adipocyte differentiation and differentiation-associated mitochondrial biogenesis. We found that DRP1 is essential for the induction of the early phase of adipogenic transcriptional program. Intriguingly, inhibition of DRP1 is dispensable following the induction of adipogenesis and adipogenesis-associated mitochondrial biogenesis. Together, we demonstrate that DRP1 in the preadipocytes plays an essential role in brown and beige adipogenesis.
Control of mammalian brain aging by the unfolded protein response (UPR)
Authors: Cabral-Miranda Felipe , Tamburini Giovani , Martinez Gabriela , Medinas Danilo , Gerakis Yannis , Miedema Tim , Duran-Aniotz Claudia , Ardiles Alvaro O. , Gonzalez Cristobal , Sabusap Carleen , Bermedo-Garcia Francisca , Adamson Stuart , Vitangcol Kaitlyn , Huerta Hernan , Zhang Xu , Nakamura Tomohiro , Sardi Sergio Pablo , Lipton Stuart A. , Kenedy Brian K. , Cárdenas Julio Cesar , Palacios Adrian G. , Plate Lars , Henriquez Juan Pablo , Hetz Claudio
Published: April 2020

Aging is the major risk factor for the development of dementia and neurodegenerative disorders, and the aging brain manifests severe deficits in buffering capacity by the proteostasis network. Accordingly, we investigated the significance of the unfolded protein response (UPR), a major signaling pathway that copes with endoplasmic reticulum (ER) stress, to normal mammalian brain aging. Genetic disruption of ER stress sensor IRE1α accelerated cognitive and motor dysfunction during aging. Exogenous bolstering of the UPR by overexpressing an active form of the transcription factor XBP1 restored synaptic and cognitive function in addition to reducing cell senescence. Remarkably, proteomic profiling of hippocampal tissue indicated that XBP1s expression corrected age-related alterations in synaptic function. Collectively, our data demonstrate that strategies to manipulate the UPR sustain healthy brain aging.

One Sentence Summary

The IRE1/XBP1 pathway dictates when and how brain function declines during aging.
Rapid, precise quantification of large DNA excisions and inversions by ddPCR
Authors: Watry Hannah L. , Feliciano Carissa M. , Gjoni Katie , Takahashi Gou , Miyaoka Yuichiro , Conklin Bruce R. , Judge Luke M.
Published: April 2020

The excision of genomic sequences using paired CRISPR-Cas nucleases is a powerful tool to study gene function, create disease models and holds promise for therapeutic gene editing. However, our understanding of the factors that favor efficient excision is limited by the lack of a rapid, accurate measurement of DNA excision outcomes that is free of amplification bias. Here, we introduce ddXR (droplet digital PCR eXcision Reporter), a method that enables the accurate and sensitive detection of excisions and inversions independent of length. The method can be completed in a few hours without the need for next-generation sequencing. The ddXR method uncovered unexpectedly high rates of large (>20 kb) excisions and inversions, while also revealing a surprisingly low dependence on linear distance, up to 170 kb. We further modified the method to measure precise repair of excision junctions and allele-specific excision, with important implications for disease modeling and therapeutic gene editing.
Exogenous L-lactate promotes astrocyte plasticity but is not sufficient for enhancing striatal synaptogenesis or motor behavior in mice
Authors: Lundquist Adam J. , Gallagher Tyler J. , Petzinger Giselle M. , Jakowec Michael W.
Published: April 2020

L-lactate is an energetic and signaling molecule that is key to the metabolic and neuroplastic connection between astrocytes and neurons and may be involved in exercise-induced neuroplasticity. This study sought to explore the role of L-lactate in astrocyte reactivity and neuroplasticity. Using in vitro cultures of primary astrocytes, we show L-lactate increased expression of plasticity-related genes, including neurotrophic factors,Bdnf, Gdnf, Cntfand the immediate early genecFos. L-lactate’s promotion of neurotrophic factor expression may be mediated in part by the lactate receptor HCAR1 since application of the HCAR1 agonist 3,5-DHBA also increased expression ofBdnfin primary astrocytes. In vivo L-lactate administration to healthy mice caused a similar increase in the expression of plasticity-related genes as well as increased astrocyte morphological complexity in a region-specific manner, with increased astrocytic response found in the striatum but not the ectorhinal cortex, regions of the brain where increases in regional cerebral blood flow are increased or unaltered, respectively, with motor behavior. Additionally, L-lactate administration did not cause synaptogenesis or improve motor behavior based on the latency to fall on the accelerating rotarod, suggesting that L-lactate administration can initiate astrocyte-specific gene expression, but the activation of motor circuits is necessary to initiate striatal neuroplasticity. These results suggest that peripheral L-lactate is likely an important molecular component of exercise-induced neuroplasticity by acting in an astrocyte-specific manner to prime the brain for neuroplasticity.
Correcting False Memories: The Effect of Mnemonic Generalization on Original Memory Traces
Authors: Muncy Nathan M. , Kirwan C. Brock
Published: April 2020

False memories are a common occurrence but the impact of misremembering on the original memory trace is ill-described. While the original memory may be overwritten, it is also possible for a second false memory to exist concurrently with the original, and if a false memory exists concurrently then recovery of the original information should be possible. This study investigates first, whether false recognition overwrites the original memory representation using a mnemonic discrimination task, and second, which neural processes are associated with recovering the original memory following a false memory. Thirty-five healthy, young adults performed multiple recognition memory tests, where the design of the experiment induced participants to make memory errors in the first recognition memory test and then allowed us to determine whether the memory error would be corrected in the second test. FMRI signal associated with the encoding and retrieval processes during the experiment were investigated in order to determine the important regions for false memory correction. We found that false memories do not overwrite the original trace in all instances, as recovery of the original information was possible. Critically, we determined that recovery of the original information was dependent on higher-order processes during the formation of the false memory during the first test, and not on processing at the time of encoding nor the second test.
Zinc Oxide Nanoparticles (ZnONPs) as Nanofertilizer: Improvement on Seed Yield and Antioxidant Defense System in Soil Grown Soybean (Glycine maxcv. Kowsar)
Authors: Yusefi-Tanha Elham , Fallah Sina , Rostamnejadi Ali , Pokhrel Lok Raj
Published: April 2020

Herein, we investigated potential phytotoxicity of zinc oxide nanoparticles (ZnONPs) on seed yield, focusing on particle size-, morphology-, and concentration-dependent responses of multiple antioxidant defense biomarkers, in soil-grown soybean (Glycine maxcv. Kowsar) during its lifecycle. To this end, we synthesized three types of morphologically unique ZnONPs (spherical/ 38nm, floral-like/ 59nm, and rod-like/ >500nm); all with high purity, triclinic crystal structure and negative surface charge; and compared the toxicity with Zn2+ions. Each pot received two seeds, placed in soil inoculated with N-fixing bacteria (Rhizobium japonicum) and grown outdoor for 120 days. Our findings demonstrated a significant particle size-, morphology-, and concentration-dependent influence of ZnONPs on seed yield, lipid peroxidation, and various antioxidant biomarkers in soybean. Our spherical 38nm ZnONPs were the most protective compared to the floral-like 59nm ZnONPs, rod-like >500nm ZnONPs, and Zn2+ions, particularly up to 160 mg/kg. However, at the highest concentration of 400 mg/kg, spherical 38nm ZnONPs elicited the highest oxidative stress responses (H2O2synthesis, MDA, SOD, CAT, POX) in soybean compared to the other two morphologically different ZnONPs tested. The concentrationresponse curves for the three types of ZnONPs and Zn2+ions were nonlinear (nonmonotonous) for all the endpoints evaluated. The results also suggest differential nano-specific toxicity of ZnONPs compared to ionic Zn2+toxicity in soybean. Our higher NOAEL value of 160 mg/kg indicates the potential for ZnONPs to be used as a nanofertilizer for crops grown in Zn-deficient soils to improve crop yield, food quality and address malnutrition, globally.

Highlights

Particle size-, morphology-, and concentration-dependent effects of ZnONPs tested.

All Zn compounds (ZnONPs, Zn2+) promoted seed yield up to 160 mg/kg.

Spherical 38nm ZnONPs elicited the least oxidative stress, except at 400 mg/kg.

Concentration-response curves for all Zn compounds were non-linear.

ZnONPs may serve as nanofertilizer for enriching Zn-deficit soil with Zn.

Abstract Figure

TOC Art
Specific PIP2Binding Promotes Calcium Activation of TMEM16A Chloride Channels
Authors: Jia Zhiguang , Chen Jianhan
Published: April 2020

TMEM16A is a widely expressed Ca2+-activated Cl-channel that regulates crucial physiological functions including fluid secretion, neuronal excitability, and smooth muscle contraction. There is a critical need to understand the molecular mechanisms of TMEM16A gating and regulation. However, high-resolution TMEM16A structures have failed to reveal an activated state with unobstructed permeation pathway even with saturating Ca2+. This has been attributed to the requirement of PIP2for preventing TMEM16A desensitization. Here, we show that specific binding PIP2to TMEM16A can lead to spontaneous opening of the permeation pathway in the Ca2+-bound state. The predicted activated state is highly consistent with a wide range of mutagenesis and functional data. It yields a maximal Cl-conductance of ~1 pS, similar to experimental estimates, and recapitulates the selectivity of larger SCN-over Cl-. The resulting molecular mechanism of activation provides a basis for understanding the interplay of multiple signals in controlling TMEM16A channel function.
Synaptotagmin-7 participates in the regulation of acetylcholine release and short-term presynaptic facilitation in splanchnic nerve terminals
Authors: Caballero-Florán René N. , Bendahmane Mounir , Philippe Julie M. , Morales Alina , Anantharam Arun , Jenkins Paul M.
Published: April 2020

Disturbances that threaten homeostasis elicit activation of the sympathetic nervous system (SNS) and the adrenal medulla. The effectors discharge as a unit to drive global and immediate changes in whole-body physiology. Descending sympathetic information is conveyed to the adrenal medulla via preganglionic splanchnic fibers. These fibers pass into the gland and synapse onto chromaffin cells, which synthesize, store, and secrete catecholamines and vasoactive peptides. While the importance of the sympatho-adrenal branch of the autonomic nervous system has been appreciated for many decades, the mechanisms underlying transmission between presynaptic splanchnic neurons and postsynaptic chromaffin cells have remained obscure. In contrast to chromaffin cells, which have enjoyed sustained attention as a model system for exocytosis, even the Ca2+sensors that are expressed within splanchnic terminals have not yet been identified. This study shows that a ubiquitous Ca2+-binding protein, synaptotagmin-7 (Syt7), is expressed within the fibers that innervate the adrenal medulla, and that its absence can alter synaptic transmission in the preganglionic terminals of chromaffin cells. The prevailing impact in presynapses that lack Syt7 is a decrease in synaptic strength and neuronal short-term plasticity. Evoked excitatory postsynaptic currents (EPSCs) in Syt7 KO preganglionic terminals are smaller in amplitude than in wild-type synapses stimulated in an identical manner. Splanchnic inputs also display robust short-term presynaptic facilitation, which is compromised in the absence of Syt7. These data reveal, for the first time, a role for any synaptotagmin at the splanchnic-chromaffin cell synapse. They also suggest that Syt7 has actions at synaptic terminals that are conserved across central and peripheral branches of the nervous system.
Proteogenomic Analysis of Pancreatic Cancer Subtypes
Authors: Kafita Doris , Nkhoma Panji , Zulu Mildred , Sinkala Musalula
Published: April 2020

Pancreatic cancer remains a significant public health problem with an ever-rising incidence of disease. Cancers of the pancreas are characterised by various molecular aberrations, including changes in the proteomics and genomics landscape of the tumour cells. There is a need, therefore, to identify the proteomic landscape of pancreatic cancer and the specific genomic and molecular alterations associated with disease subtypes. Here, we carry out an integrative bioinformatics analysis of The Cancer Genome Atlas dataset that includes proteomics and whole-exome sequencing data collected from pancreatic cancer patients. We apply unsupervised clustering on the proteomics dataset to reveal the two distinct subtypes of pancreatic cancer. Using functional and pathway analysis, we demonstrate the different molecular processes and signalling aberrations of the pancreatic cancer subtypes. We explore the clinical characteristic of these subtypes to show differences in disease outcome. Using datasets of mutations and copy number alterations, we show that various signalling pathways are altered among pancreatic tumours, including the Wnt pathway, Notch pathway and PI3K-mTOR pathways. Altogether, we reveal the proteogenomic landscape of pancreatic cancer subtypes and the altered molecular processes which can be leveraged to devise more effective treatments.
Analysis of FGF20-regulated genes in organ of Corti progenitors by translating ribosome affinity purification
Authors: Yang Lu M. , Stout Lisa , Rauchman Michael , Ornitz David M.
Published: April 2020

Background

Understanding the mechanisms that regulate hair cell (HC) differentiation in the organ of Corti (OC) is essential to designing genetic therapies for hearing loss due to HC loss or damage. We have previously identified Fibroblast Growth Factor 20 (FGF20) as having a key role in HC and supporting cell differentiation in the mouse OC. To investigate the genetic landscape regulated by FGF20 signaling in OC progenitors, we employ Translating Ribosome Affinity Purification combined with Next Generation mRNA Sequencing (TRAPseq) in theFgf20lineage.

Results

We show that TRAPseq targeting OC progenitors effectively enriched for mRNA within this rare cell population. TRAPseq identified differentially expressed genes downstream of FGF20, includingEtv4, Etv5, Etv1, Dusp6, Hey1, Hey2, Heyl, Tectb, Fat3, Cpxm2, Sall1, Sall3, and cell cycle regulators such asCdc20. Analysis ofCdc20conditional-null mice identified decreased cochlea length, while analysis ofSall1-ΔZn2-10mice, which harbor a mutation that causes Townes-Brocks syndrome, identified a decrease in outer hair cell number.

Conclusions

We present two datasets: genes with enriched expression in OC progenitors, and genes regulated by FGF20 in the embryonic day 14.5 cochlea. We validate select differentially expressed genes via in situ hybridization and in vivo functional studies in mice.

Key findings

Translating Ribosome Affinity Purification (TRAP) with Fgf20-Cre enriches for prosensory cell mRNA

TRAP combined with RNAseq identifies genes downstream of FGF20 during prosensory cell differentiation

FGF20 regulates Sall1, gene implicated in human sensorineural hearing loss

Grant Sponsor and Number

National Institute on Deafness and Other Communication Disorders – DC017042 (DMO) Washington University Institute of Clinical and Translational Sciences and National Center for Advancing Translational Sciences – CTSA grant UL1TR002345 (JIT471 to DMO) March of Dimes – 6-FY13-127 (MR)
Insulin promoted mobilization of GLUT4 from a perinuclear storage site requires RAB10
Authors: Brumfield Alexandria , Chaudhary Natasha , Molle Dorothee , Wen Jennifer , Graumann Johannes , McGraw Timothy E.
Published: April 2020

Insulin controls glucose uptake into muscle and fat cells by inducing a net redistribution of GLUT4 from intracellular storage to the plasma membrane (PM). The TBC1D4-RAB10 signaling module is required for insulin-stimulated GLUT4 translocation to the PM, although where it intersects GLUT4 traffic was unknown. Here we demonstrate that TBC1D4-RAB10 functions to control GLUT4 mobilization from a Trans Golgi Network (TGN) storage compartment, establishing that insulin, in addition to regulating the PM proximal effects of GLUT4-containing vesicles docking to and fusion with the PM, also directly regulates the behavior of GLUT4 deeper within the cell. We also show that GLUT4 is retained in an element/domain of the TGN from which newly synthesized lysosomal proteins are targeted to the late endosomes and the ATP7A copper transporter is translocated to the PM by elevated copper. Insulin does not mobilize ATP7A nor does copper mobilize GLUT4. Consequently, GLUT4 intracellular sequestration and mobilization by insulin is achieved, in part, through utilizing a region of the TGN devoted to specialized cargo transport in general rather than being specific for GLUT4. Our results define GLUT4-containing region of the TGN as a sorting and storage site from which different cargo are mobilized by distinct signals.
Alpha-satellite RNA transcripts are repressed by centromere-nucleolus associations
Authors: Bury Leah , Moodie Brittania , McKay Liliana S. , Miga Karen H. , Cheeseman Iain M.
Published: April 2020

Centromeres play a fundamental role in chromosome segregation. Although originally thought to be silent chromosomal regions, centromeres are actively transcribed. However, the behavior and contributions of centromere-derived RNAs have remained unclear. Here, we used single-molecule fluorescence in-situ hybridization (smFISH) to detect alpha-satellite RNA transcripts in intact human cells. We find that alpha-satellite RNA smFISH foci fluctuate in their levels over the cell cycle and do not remain associated with centromeres, displaying localization consistent with other long non-coding RNAs. Our results demonstrate that alpha-satellite expression occurs through RNA Polymerase II-dependent transcription, but does not require centromere proteins and other cell division components. Instead, our work implicates centromere-nucleolar associations as the major factor regulating alpha-satellite expression. The fraction of nucleolar-localized centromeres inversely correlates with alpha-satellite transcripts levels, explaining variations in alpha-satellite RNA between cell lines. In addition, alpha-satellite transcript levels increase substantially when the nucleolus is disrupted. Together, our results are inconsistent with a direct, physical role for alpha-satellite transcripts in cell division processes, and instead support a role for ongoing transcription in promoting centromere chromatin dynamics. The control of alpha-satellite transcription by centromere-nucleolar contacts provides a mechanism to modulate centromere transcription and chromatin dynamics across diverse cell states and conditions.
Discussion of (dis)aggregated earnings guidance and acquisition financing
Authors: Zhang Joseph H.
Published: April 2020

Purpose

The author discusses the paper by Ordyna (2020) and suggests a few areas for improvement. First, the author could think more about the financing scheme of the acquisition including hybrid debt securities. Second, the author could consider forecast reputation, the timing and frequency of earnings guidance. Third, the author may consider the difference-in-differences research design and identification strategy. Other model designs, robustness checks and alternative measures of key variables are discussed.
“Yes Madam”: digitized services right here and right now
Authors: Singh Shikha , Mittal Shweta
Published: April 2020

Learning outcomes

The case helps to understand: the working mechanisms of a digitized salon service, with a focus on the lower- and middle-income strata. The changing scenario of the service marketing model, with the growth in digital service models. To investigate the organisational challenges of a digitally facilitated/based start-up and find solutions to overcome the challenges.

Case overview/synopsis

“Yes Madam”-salon at home was a business enterprise, providing beauty and wellness services at the doorstep through a mobile application and web-based platform. The case describes the reason for opening the doorstep beauty services, its revenue model and aims to provide quality services to lower- and middle-income strata. The case will help students to understand the working mechanism of digitized salon services and associated challenges; prominent ones being attracting, selecting and retaining the beauticians and providing the standardised services. The case has examined the low-price services for the consumers delivered by the company. The case also discussed their plans for diversification and penetration into the untapped markets.

Complexity academic level

Graduates and postgraduates.

Supplementary materials

Teaching Notes are available for educators only.

Subject code

CSS 3: Entrepreneurship.
An examination of the effects of outsourcing ticket sales force management
Authors: Popp Nels , Jensen Jonathan A. , McEvoy Chad D. , Weiner James F.
Published: April 2020

Purpose

The purpose of the study is to ascertain whether sport organizations which outsource ticket sales force management outperform sports organizations which manage their ticket sales force internally, relative to ticket revenue and attendance.

Design/methodology/approach

Thirteen years of ticket revenue and football attendance data were collected for National Collegiate Athletic Association (NCAA) Football bowl subdivision (FBS) Division I Athletics Departments (n = 126), as well as data on whether the organization employed an external (outsourced), internal or no ticket sales force. The number of salespeople employed was also captured. Within-subjects, fixed effects regression models, which included several control variables such as number of home contests, prior season attendance, team success and population, were run to assess the relationship between sales force type and both ticket revenue and attendance, for one year, two years and three years after sales force establishment.

Findings

All models were significant. While both internally managed ticket sales forces and those managed by outsourced firms saw significant increases in ticket revenue (compared to not employing a sales force), internally managed departments outperformed third parties. In addition, departments utilizing outsourcing companies reported lower attendance for the first two years after outsourcing, but attendance differences were negligible by the third year of outsourcing.

Practical implications

The results of the study provide data to help sport managers determine whether outsourcing sales functions within an organization will lead to greater ticket revenue and/or attendance.

Originality/value

While several sport management studies have examined the decision-making process of outsourcing organizational functions, no prior studies have examined the financial implications of doing so.
Patterns of IT use: the impact on green supply chain management and firm performance
Authors: Jiang Shenyang , Han Zhaojun , Huo Baofeng
Published: April 2020

Purpose

This study aims to explore how different patterns of IT use influence different types of green supply chain management (GSCM) with customers, and in turn, environmental and economic performance.

Design/methodology/approach

Based on data collected from 206 manufacturing companies in China, the authors used structural equation modeling (SEM) with the maximum-likelihood estimation (MLE) method to test the conceptual model and the related hypotheses.

Findings

The results show that both IT use for exploitation and IT use for exploration are positively related to green strategy alignment and green process coordination, whereas the relationship between IT use for exploration and green strategy alignment is weaker. This study also finds that green strategy alignment has a marginal positive effect on economic performance, whereas its effect on environmental performance is not significant. Green process coordination has a positive effect on environmental performance, whereas its effect on economic performance is not significant.

Originality/value

This study extends the value of IT use in the GSCM field, enriching both literature on IT and GSCM. The findings provide significant managerial implications for managers to leverage IT resources to enhance GSCM and the corresponding performance.
Moonlighting in Ghana's higher education institutions: exploring lecturers' experiences at the Ghana Institute of Management and Public Administration (GIMPA)
Authors: Sakyi Emmanuel Kojo , Agomor Kingsley Senyo
Published: April 2020

Purpose

This paper aims to examine lecturers' experiences of moonlighting in the Ghana Institute of Management and Public Administration (GIMPA).

Design/methodology/approach

A qualitative approach was used. Data were collected through in-depth semi-structured interviews with 18 purposively selected informants. Data were transcribed and analyzed thematically.

Findings

The findings are that moonlighting is common at GIMPA, and the institutional environment is conducive for the practice. Knowledge of the practice is unclear. However, moonlighting serves as a source of additional income for lecturers, which a significant majority describe as enabling their continuing employment at GIMPA, but many pointed out the negative effects as well. Lack of a policy to control the behavior has been cited as a reason for the problem, which left lecturers to self-determine what to do. Moonlighting practice is affecting the quality of teaching and support to students by the lecturers.

Research limitations/implications

The sample of the respondents who participated in the study is small and limited to 18. Their views cannot be generalized to all higher education institutions. But, the results show the seriousness of the problem and its implications.

Practical implications

Moonlighting is prevalent in GIMPA. It suggests that employees of other public higher education institutions are no immune to it.

Originality/value

This study is the first of its kind to explore the practice of moonlighting in a quasi-public higher education institution in Ghana. It has added to the empirical literature on the practice and the effects on the institution.
The dynamics of cause-related marketing platform and interactivity on college sport fans' donations
Authors: Hwang Geumchan , Chung Kyu-soo
Published: April 2020

Purpose

This study aims to examine how sport fans' intention to donate to college athletics differs by the type of communication and by the interactivity of communication when a college athletic department uses a social cause for marketing.

Design/methodology/approach

To discover differences in donation intention, the study adopts a two (social media/newspaper) by two (interactive/non-interactive) factorial experiment in which the study's created scenario is randomly presented to subjects. Participating in the online survey are 184 collegiate sport fans at a university in the American Midwest. Collected data are analyzed on the analysis of variance.

Findings

Results show that fans demonstrating the highest donation intention are those in the group of fan-interactive marketing on social media. Those showing the lowest are in the group of non-interactive marketing on newspaper. Between marketing interactivity and marketing platform, no interaction effect is found.

Originality/value

The study tests the effectiveness of marketing communication in the context of collegiate sports and identifies the impact of social media on college sport fans' donation intention. For collegiate athletic administrators designing a cause-related marketing campaign, this study provides practical information on how to use social media in delivering fan-oriented activities.
Shame and (“managed”) resentment: Emotion and entitlement among Israeli mothers living in poverty
Authors: Benjamin Orly
Published: April 2020

Of the range of negative emotional states, shame is commonly found to characterize experiences of people living in poverty. However, relatively little attention has been directed toward exploring other emotions that accompany the shame. Not exploring other emotions, the possibility that working‐class mothers go through a struggling emotional experience in relation to their experiences of how authorities validate their belonging, is left out of scope. Exploring the notion of resentment creates a conceptual space for considering this possibility, as it flags the importance of belonging and entitlement for mothers living in poverty. I analyze these issues here, by applying “translocational positionality” which stresses how people take up positions relating to experiences of (non‐) belonging and entitlement which are informed by struggles over inclusion and resources. As such, it stresses the links between struggles of belonging and struggles for securing access to resources. It affords the opportunity to identify the emotional/affectual dimension of struggles that would otherwise be implicit at best. A Resentment focused analysis of structured interviews conducted with 90 mothers, from seven ethno‐national categories, living in poverty in Israel enabled me to analyze issues of belonging and entitlement as part of a continuous struggle for resources, pitched against welfare practices which ostensibly support mothers and families in need, but in fact apply means‐tested and other exclusionary principles to leave mothers without the assistance that would protect them from shame.
Do populist values or civic values drive support for referendums in Europe?
Authors: ROSE RICHARD , WEßELS BERNHARD
Published: April 2020

Representative democracy gives voters the right to influence who governs but its influence on policy making is only indirect. Free and fair referendums give voters the right to decide a policy directly. Elected representatives usually oppose referendums as redundant at best and as undermining their authority at worst. Democratic theorists tend to take electing representatives as normal and as normatively superior. The nominal association of popular decision making and populism has strengthened this negative view. Public opinion surveys show substantial support for holding referendums on important issues. Two major theories offer contrasting explanations for popular support for referendums; they reflect populist values or a commitment to the civic value of participation. This innovative paper tests an integrated model of both theories by the empirical analysis of a 17‐country European survey. There is substantial support for all three civic hypotheses: referendum endorsement is positively influenced by attitudes towards participation, democratic ideals and whether elected representatives are perceived as responsive. By contrast, there is no support for populist hypotheses that the socioeconomically weak and excluded favour referendums and minimal support for the effect of extreme ideologies. The conclusion shows that most criticisms of referendums also apply to policy making by elected representatives. While referendums have limits on their use, there is a democratic argument for holding such ballots on major issues to see whether or not a majority of voters endorse the choice of their nominal representatives.
Lung immune prognostic index as a prognostic factor in patients with small cell lung cancer
Authors: Sonehara Kei , Tateishi Kazunari , Komatsu Masamichi , Yamamoto Hiroshi , Hanaoka Masayuki
Published: April 2020

Background

The lung immune prognostic index (LIPI) is a marker that combines the derived neutrophil‐to‐lymphocyte ratio (dNLR) and serum lactate dehydrogenase (LDH) level and is a recently reported prognostic factor of immune checkpoint inhibitor therapy for non‐small cell lung cancer (NSCLC). However, there are no reports regarding the prognostic value of LIPI in small cell lung cancer (SCLC).

Methods

We retrospectively enrolled 171 patients diagnosed with SCLC and treated at Shinshu University School of Medicine between January 2003 and November 2019. Progression‐free survival (PFS) and overall survival (OS) were compared according to LIPI, and we investigated whether LIPI could be a prognostic factor in SCLC using the Kaplan‐Meier method and univariate and multivariate Cox models.

Results

The median OS of the LIPI 0 group was significantly longer than that of the LIPI 1 plus 2 group (21.0 vs. 11.6 months, P < 0.001). The multivariate analysis associated with OS indicated that LIPI 1 plus 2 was an independent unfavorable prognostic factor in addition to poor performance status (2–3), old age (≥ 75 years) and stage (extensive disease [ED]). However, PFS of the LIPI 0 group was not significantly different from that of the LIPI 1 plus 2 group. In ED‐SCLC patients, the median PFS and OS of the LIPI 0 group were significantly longer than those of the LIPI 2 group (6.6 vs. 4.0 months, P = 0.006 and 17.1 vs. 5.9 months, P < 0.001, respectively).

Conclusions

We confirmed the prognostic value of LIPI in SCLC, especially ED‐SCLC.

Key points

Significant findings of the study: The present study is the first to demonstrate that pretreatment lung immune prognostic index is an independent prognostic factor associated with overall survival for small cell lung cancer.

What this study adds: The utility of the lung immune prognostic index as a prognostic factor for small cell lung cancer.
Financial Reporting and Trade Credit: Evidence from Mandatory IFRS Adoption*
Authors: Li Xiao , Ng Jeffrey , Saffar Walid
Published: April 2020

We investigate the effect of mandatory IFRS adoption on trade credit. We document that firms in countries that adopt IFRS receive more trade credit from their suppliers, consistent with improved financial reporting quality and comparability playing a role in facilitating informal financing. This increase is larger for countries with a low level of societal trust, a poor pre‐IFRS‐adoption information environment, and stronger legal enforcement. These cross‐sectional results suggest that the conditions under which higher‐quality information is made publicly available affect suppliers' decisions to provide trade credit. This increase is also larger for firms with greater exposure to foreign markets, a finding that highlights the importance of more comparable international financial reporting standards in facilitating cross‐country trade credit. We also find that IFRS adoption has a stronger positive effect on trade credit for firms with greater liquidity needs. Finally, we find that firms in countries that adopt IFRS also extend more trade credit to their customers. Overall, our results support the notion that financial reporting can have a causal effect on trade credit.
Prevalence and description of kratom (Mitragyna speciosa) use in the United States: a cross‐sectional study
Authors: Schimmel Jonathan , Amioka Elise , Rockhill Karilynn , Haynes Colleen M. , Black Joshua C. , Dart Richard C. , Iwanicki Janetta L.
Published: April 2020

Background and aims

Mitragyna speciosa(‘kratom’) contains mu opioid partial agonists. It is widely available, and occasionally used as a home remedy for opioid use disorder. The Drug Enforcement Agency considers kratom a drug of concern; however, prevalence of use and role in drug misuse are unknown. This study aimed to characterize kratom use in the United States.

Design

Cross‐sectional Survey of Non‐Medical Use of Prescription Drugs (NMURx) Program, 2018 third quarter and 2019 first quarter.

Setting

A validated non‐probability online survey in the United States.

Participants

A total of 59 714 respondents aged 18 years or older, weighted to represent the adult US population (n = 252 063 800).

Measurements

In addition to prevalence of past‐year kratom and other drug use, behavior proportions were estimated. The Drug Abuse Screening Test (DAST‐10) estimated consequences of drug abuse.

Findings

The estimated prevalence of past‐year kratom use in the adult US population was 0.8% [95% confidence interval (CI) = 0.7–0.9], representing 2 031 803 adults. Life‐time prevalence was 1.3% (95% CI = 1.2–1.4), representing 3 353 624 adults. Kratom users were younger (mean 35 years,P < 0.001), with higher proportions of males (61.0 versus 48.6%,P < 0.001), students (14.1 versus 7.5%,P < 0.001) and health‐care professionals (9.7 versus 4.5%,P < 0.001) and fewer bachelor's/advanced degree graduates (33.4 versus 42.6%,P < 0.001) compared with non‐users. Results were inconclusive on whether there was a difference in kratom use by race, household income or employment status. Among those with past‐year kratom use, 36.7% (95% CI = 32.1–41.3) non‐medically used prescription opioids, 21.7% (95% CI = 18.0–25.5) used illicit opioids, 54.4% (95% CI = 49.5–59.3) used another illicit drug and 67.1% (95% CI = 62.5–71.8) used cannabis. The DAST‐10 profile was more often substantial/severe in kratom users (21 versus 1%,P < 0.001) compared with non‐users.

Conclusions

Estimated United States past‐year prevalence of kratom use is 0.8%, and kratom users tend to have more serious substance abuse profiles than non‐users or users of cannabis, alcohol or cigarettes. To our knowledge, this is the first description of kratom use at the national level.