bluuebunny/crossref_metadata_2025_split huggingface dataset:
THEMIS is a priming substrate of non-receptor tyrosine phosphatase PTPN6/SHP1 and plays dual roles during T cell development
Authors: Zhang Jiali , Zuo Erwei , Song Minfang , Chen Li , Jiang Zhenzhou , Chen Shengmiao , Xiong Xuexue , Wang Yuetong , Hao Piliang , Horng Tiffany , Zhuang Min , Zhang Liye , Wang Haopeng , Fan Gaofeng 
Published: December 2021

AbstractTHEMIS plays an indispensable role in T cells, but its mechanism of action is highly controversial. Using the systematic proximity labeling methodology PEPSI, we identified THEMIS as an uncharacterized substrate for the phosphatase SHP1. Saturated mutagenesis analysis revealed that THEMIS phosphorylation at the evolutionally conserved Tyr34 residue was oppositely regulated by SHP1 and the kinase LCK. Like THEMIS-/-mice, THEMISY34F/Y34Fknock-in mice showed a significant decrease in CD4 thymocytes and mature CD4 T cells, but a normal thymic development and peripheral homeostasis of CD8 T cells. Mechanistically, phosphorylated THEMIS induced by TCR activation acts as a “priming substrate” to bind SHP1 and convert its phosphatase activity from basal level to nearly fully activated level, ensuring an appropriate negative regulation of TCR signaling. However, cytokine signaling in CD8 T cells failed to elicit THEMIS Y34 phosphorylation, revealing both phosphorylation-dependent and -independent roles of THEMIS in controlling T cell maturation and expansion.
The C-terminal tail of polycystin-1 suppresses cystic disease in a mitochondrial enzyme-dependent fashion
Authors: Onuchic Laura , Padovano Valeria , Schena Giorgia , Rajendran Vanathy , Dong Ke , Gresko Nikolay P. , Shi Xiaojian , Shen Hongying , Somlo Stefan , Caplan Michael J. 
Published: December 2021

SUMMARYAutosomal dominant polycystic kidney disease (ADPKD) is the most prevalent potentially lethal monogenic disorder. Approximately 78% of cases are caused by mutations in the PKD1 gene, which encodes polycystin-1 (PC1). PC1 is a large 462-kDa protein that undergoes cleavage in its N and C-terminal domains. C-terminal cleavage produces fragments that translocate to mitochondria. We show that transgenic expression of a protein corresponding to the final 200 amino acid residues of PC1 in a Pkd1-KO orthologous murine model of ADPKD dramatically suppresses cystic phenotype and preserves renal function. This suppression depends upon an interaction between the C-terminal tail of PC1 and the mitochondrial enzyme Nicotinamide Nucleotide Transhydrogenase. This interaction modulates tubular/cyst cell proliferation, the metabolic profile, mitochondrial function and the redox state. Together, these results suggest that a short fragment of PC1 is sufficient to suppress cystic phenotype and open the door to the exploration of gene therapy strategies for ADPKD.
Liquid-liquid phase separation facilitates the biogenesis of secretory storage granules
Authors: Parchure Anup , Tian Meng , Boyer Cierra K , Bearrows Shelby C , Rohli Kristen E , Zhang Jianchao , Ramazanov Bulat R , Wang Yanzhuang , Stephens Samuel B , von Blume Julia 
Published: December 2021

AbstractInsulin is a key regulator of human metabolism, and its dysfunction leads to diseases such as type 2 diabetes. It remains unknown how proinsulin is targeted from the trans-Golgi network (TGN) to secretory storage granules as no cargo receptor has been identified. Chromogranin proteins (CGs) are central regulators of granule biosynthesis, and it was proposed that their aggregation is critical for this process. However, the molecular mechanism by which these molecules facilitate sorting at the TGN is poorly understood. Here, we show that CGs undergo liquid–liquid phase separation (LLPS) at low pH independently of divalent cations, such as calcium. Liquid CG condensates, but not aggregates, recruit and sort proinsulin and other granule-destined cargo molecules towards secretory granules. Cargo selectivity is independent of sequence or structural elements but is based on the size and concentration of the client molecules at the TGN. Finally, electrostatic interactions and the N-terminal intrinsically disordered domain of chromogranin B facilitate LLPS and are critical for granule formation. We propose that phase-separated CGs act as a “cargo sponge” within the TGN lumen, gathering soluble client proteins into the condensate independently of specific sequence or structural elements, facilitating receptor-independent sorting. These findings challenge the canonical TGN sorting models and provide insights into granule biosynthesis in insulin-secreting β-cells.One sentence summaryLiquid Chromogranin condensates recruit cargo molecules at the TGN for their delivery to secretory storage granules.
Live-cell microscopy or fluorescence anisotropy with budded baculoviruses - which way to go with measuring ligand binding to M4 muscarinic receptors?
Authors: Tahk Maris-Johanna , Torp Jane , Ali Mohammed A.S. , Fishman Dmytro , Parts Leopold , Grätz Lukas , Müller Christoph , Keller Max , Veiksina Santa , Laasfeld Tõnis , Rinken Ago 
Published: December 2021

AbstractM4 muscarinic receptor is a G protein-coupled receptor that has been associated with alcohol and cocaine abuse, Alzheimer’s disease and schizophrenia which makes it an interesting drug target. For many G protein-coupled receptors, the development of high-affinity fluorescence ligands has expanded the options for high throughput screening of drug candidates and serve as useful tools in fundamental receptor research. So far, the lack of suitable fluorescence ligands has limited studying M4 receptor ligand binding. Here, we explored the possibilities of using fluorescence-based methods for studying binding affinity and kinetics to M4 receptor of both labeled and unlabeled ligands. We used two TAMRA-labeled fluorescence ligands, UR-MK342 and UR-CG072, for assay development. Using budded baculovirus particles as M4 receptor preparation and fluorescence anisotropy method, we determined the affinities and binding kinetics of both fluorescence ligands. The fluorescence ligands could also be used as reported probes for determining binding affinities of a set of unlabeled ligands. Based on these results, we took a step further towards a more natural signaling system and developed a method using live CHO-K1-hM4R cells and automated fluorescence microscopy suitable for routine determination of unlabeled ligand affinities. For quantitative image analysis, we developed random forest and deep learning-based pipelines for cell segmentation. The pipelines were integrated into the user-friendly open-source Aparecium software. Both developed methods were suitable for measuring fluorescence ligand saturation binding, association and dissociation kinetics as well as for screening binding affinities of unlabeled ligands.Abstract Figure
Preserving protein homeostasis prevents motor impairment in DNA Damage Response-compromised C. elegans
Authors: Huiting Wouter , Duque-Jaramillo Alejandra , Seinstra Renée I. , Kampinga Harm. H. , Nollen Ellen A.A. , Bergink Steven 
Published: December 2021

ABSTRACTTo maintain genome integrity, cells rely on a complex system of DNA repair pathways and cell cycle checkpoints, together referred to as the DNA damage response (DDR). Impairments in DDR pathways are linked to cancer, but also to a wide range of degenerative processes, frequently including progressive neuropathy and accelerated aging. How defects in mechanistically distinct DDR pathways can drive similar degenerative phenotypes is not understood. Here we show that defects in various DDR components are linked to a loss of protein homeostasis in Caenorhabditis elegans. Prolonged silencing of atm-1, brc-1 or ung-1, central components in respectively checkpoint signaling, double strand break repair and base excision repair enhances the global aggregation of proteins occurring in adult animals, and accelerates polyglutamine protein aggregation in a model for neurodegenerative diseases. Overexpression of the molecular chaperone HSP-16.2 prevents enhanced protein aggregation in atm-1, brc-1 or ung-1-compromised animals. Strikingly, rebalancing protein homeostasis with HSP-16.2 almost completely rescues age-associated impaired motor function in these animals as well. This reveals that the consequences of a loss of atm-1, brc-1 or ung-1 converge on an impaired protein homeostasis to cause degeneration. These findings indicate that a loss of protein homeostasis is a crucial downstream consequence of DNA repair defects, and thereby provide an attractive novel framework for understanding the broad link between DDR defects and degenerative processes.
A novel zebrafish model of SPEG-related centronuclear myopathy (CNM): characterization and comparison with other CNM model zebrafish
Authors: Espinosa Karla G. , Geissah Salma , Groom Linda , Volaptti Jonathan , Scott Ian C. , Dirksen Robert T. , Zhao Mo , Dowling James J. 
Published: December 2021

AbstractCentronuclear myopathy (CNM) is a congenital neuromuscular disorder caused by pathogenic variation in genes associated with membrane trafficking and excitation-contraction coupling (ECC). Bi-allelic autosomal recessive mutations in striated muscle enriched protein kinase (SPEG) account for a subset of CNM patients. Previous research has been limited by the perinatal lethality of Speg knockout mice. Thus, the precise biological role of SPEG in skeletal muscle remains unknown. To address this issue, we generated zebrafish spega, spegb, and spega/spegb (speg-DKO) mutant lines. We demonstrate that speg-DKO zebrafish faithfully recapitulate multiple phenotypes associated with human CNM, including disruption of the ECC protein machinery, dysregulation of calcium homeostasis during ECC, and impairment of muscle performance. Taking advantage of the availability of zebrafish models of multiple CNM genetic subtypes, we compared novel and known disease markers in speg-DKO with mtm1-KO and DNM2-S619L transgenic zebrafish. We observed desmin (DES) accumulation common to all CNM subtypes, and DNM2 upregulation in muscle of both speg-DKO and mtm1-KO zebrafish. In all, we establish a new model of SPEG-related CNM, and identify abnormalities in this model suitable for defining disease pathomechanisms and evaluating potential therapies.Summary StatementWe created a novel zebrafish speg mutant model of centronuclear myopathy that recapitulates key features of the human disorder and provides insight into pathomechanisms of the disease.
Sexual and individual signatures are encoded in the temporal rate of Cape gannet display calls
Authors: Bowmaker-Falconer Kezia , Thiebault Andrea , Connan Maёlle , Aubin Thierry , Charrier Isabelle , Pistorius Pierre 
Published: December 2021

1.Abstract/SummaryVocalisations play a vital role in animal communication, as they are involved in many biological functions. Seabirds often breed in large and dense colonies, making successful recognition between mates or between parents -and offspring crucial for reproductive success. Most seabird species, including Cape gannets (Morus capensis), are monomorphic and likely rely on acoustic signals for mate selection and mate recognition. This study aimed to better understand the use of vocalisations for sex and individual recognition in Cape gannets by describing the acoustic structure of their display calls at the nest. Vocalisations of nesting Cape gannets were recorded and acoustic measurements were extracted in both temporal and frequency domains. Values of the fundamental frequency and the average of Inter-Onset-Interval appeared to be the most important acoustic variables for sex determination. Both temporal and frequency parameters showed a potential for individual identity coding, with the average units’ Inter-Onset-Interval being the most important variable for individual identification for both sexes. This study provides the first evidence of sex-specific and individual vocal signatures in adult breeding Cape gannets. From an applied perspective, identified sex specific differences could potentially be used as a non-invasive method for field-based sex-determination in research and monitoring projects on Cape gannets.
New cell biological explanations for kinesin-linked axon degeneration
Authors: Liew Yu-Ting , Voelzmann André , Pinho-Correia Liliana M. , Murphy Thomas , Tortoishell Haydn , Parkin Jill , Bailey David M.D. , Landgraf Matthias , Prokop Andreas 
Published: December 2021

AbstractAxons are the slender, up to meter-long projections of neurons that form the biological cables wiring our bodies. Most of these delicate structures must survive for an organism’s lifetime, meaning up to a century in humans. Axon maintenance requires life-sustaining motor protein-driven transport distributing materials and organelles from the distant cell body. It seems logic that impairing this transport causes systemic deprivation linking to axon degeneration. But the key steps underlying these pathological processes are little understood. To investigate mechanisms triggered by motor protein aberrations, we studied more than 40 loss- and gain-of-function conditions of motor proteins, cargo linkers or further genes involved in related processes of cellular physiology. We used one standardisedDrosophilaprimary neuron system and focussed on the organisation of axonal microtubule bundles as an easy to assess readout reflecting axon integrity. We found that bundle disintegration into curled microtubules is caused by the losses of Dynein heavy chain and the Kif1 and Kif5 homologues Unc-104 and Kinesin heavy chain (Khc). Using point mutations of Khc and functional loss of its linker proteins, we studied which of Khc’s sub-functions might link to microtubule curling. One cause was emergence of harmful reactive oxygen species through loss of Milton/Miro-mediated mitochondrial transport. In contrast, loss of the Kinesin light chain linker caused microtubule curling through an entirely different mechanism appearing to involve increased mechanical challenge to microtubule bundles through de-inhibition of Khc. The wider implications of our findings for the understanding of axon maintenance and pathology are discussed.
Functional design of bacterial superoxide:quinone oxidoreductase
Authors: Abou-Hamdan Abbas , Mahler Roman , Grossenbacher Philipp , Biner Olivier , Sjöstrand Dan , Lochner Martin , Högbom Martin , von Ballmoos Christoph 
Published: December 2021

AbstractThe superoxide anion - molecular oxygen reduced by a single electron - is produced in large amounts by enzymatic and adventitious reactions and can perform a range of cellular functions, including bacterial warfare and iron uptake, signalling and host immune response in eukaryotes. However, it also serves as precursor for more deleterious species such as the hydroxyl anion or peroxynitrite and therefore, cellular defense mechanisms for superoxide neutralization have evolved. In addition to the soluble proteins superoxide dismutase and superoxide reductase, recently the membrane embedded diheme cytochrome b561(CybB) from E. coli has been proposed to act as a superoxide:quinone oxidoreductase. Here, we confirm superoxide and cellular ubiquinones or menaquinones as natural substrates and show that quinone binding to the enzyme accelerates the reaction with superoxide. The reactivity of the substrates is in accordance with the here determined midpoint potential of the two b hemes (+48 and -23 mV / NHE). Our data suggest that the enzyme can work near the diffusion limit in the forward direction and can also catalyse the reverse reaction efficiently under physiological conditions. The data is discussed in context of described cytochrome b561 proteins and potential physiological roles of CybB.
Mechanism of stepwise electron transfer in six-transmembrane epithelial antigen of the prostate (STEAP) 1 and 2
Authors: Chen Kehan , Wang Lie , Shen Jiemin , Tsai Ah-lim , Zhou Ming , Wu Gang 
Published: December 2021

AbstractSix transmembrane epithelial antigen of the prostate (STEAP) is a family of membrane-embedded hemoproteins with four members, STEAP1-4, all of which have a transmembrane domain (TMD) that chelates a heme prosthetic group. STEAP2-4, but not STEAP1, have an intracellular oxidoreductase domain (OxRD) so that an electron transfer chain composed of NADPH, FAD, and heme is established to mediate electron transfer across cell membranes. However, it is not known whether STEAP1 can establish a physiologically relevant electron transfer chain. Here we show that reduced FAD binds to STEAP1 and enables reduction of the heme. We also show that a soluble cytochromeb5reductase can dock on STEAP1 and serve as a surrogate OxRD to reduce the heme. These results provide the first evidence that STEAP1 can support a cross-membrane electron transfer chain. It is not clear whether FAD, which relays electrons from NADPH to heme and interacts with both OxRD and TMD, remains constantly bound to the STEAPs. We found that FAD reduced by STEAP2 can be utilized by STEAP1, supporting the hypothesis that FAD is diffusible rather than staying bound to STEAP2. We determined the structure of human STEAP2 in complex with NADP+and FAD to an overall resolution of 3.2 Å by cryo-electron microscopy. The structure of STEAP2 shows that the two cofactors bind similarly to those in the STEAP4 structure and thus a diffusible FAD is likely a general feature of the electron transfer mechanism in the STEAPs. The structure of STEAP2 also shows that its extracellular regions are less structured than those of STEAP4 or STEAP1, and further experiments show that STEAP2 reduces Fe3+-NTA with a rate significantly slower than STEAP1. These results establish a solid foundation for understanding the function and mechanisms of STEAP family of proteins.
Real-time X-ray imaging of mouse cerebral microvessels in vivo using a pixel temporal averaging method
Authors: Yu Fucheng , Wang Feixiang , Li Ke , Du Guohao , Deng Biao , Xie Honglan , Yang Guoyuan , Xiao Tiqiao 
Published: December 2021

Rodents are used extensively as animal models for the preclinical investigation of microvascular-related diseases. However, motion artifacts in currently available imaging methods preclude real-time observation of microvessels in vivo. In this paper, a pixel temporal averaging (PTA) method that enables real-time imaging of microvessels in the mouse brain in vivo is described. Experiments using live mice demonstrated that PTA efficiently eliminated motion artifacts and random noise, resulting in significant improvements in contrast-to-noise ratio. The time needed for image reconstruction using PTA with a normal computer was 250 ms, highlighting the capability of the PTA method for real-time angiography. In addition, experiments with less than one-quarter of photon flux in conventional angiography verified that motion artifacts and random noise were suppressed and microvessels were successfully identified using PTA, whereas conventional temporal subtraction and averaging methods were ineffective. Experiments performed with an X-ray tube verified that the PTA method could also be successfully applied to microvessel imaging of the mouse brain using a laboratory X-ray source. In conclusion, the proposed PTA method may facilitate the real-time investigation of cerebral microvascular-related diseases using small animal models.
Does a retailer's performance depend on CSR practices? A stakeholder theory perspective from developing economy
Authors: Kumar Anil , Singh Rohit Kr 
Published: December 2021

PurposeThe study aims to examine the relationship between retailer's performance and corporate social responsibility (CSR) practices in Indian context. The article introduces a new conceptual model considering the parameters as per the stakeholder theory perspective.Design/methodology/approachThe authors conducted empirical research with CSR practices (CSRP) and other parameters to evaluate the retailers' performance using stakeholder theory. The authors present the results from 292 valid responses from the Indian retailers. The study used structured equation modeling (SEM) to present the analysis and the results.FindingsFindings indicate that CSRP along with additional constructs loyalty (L), reputation (R), customer satisfaction (CS) and competitive advantage (CA) have positive and significant impact on organizational performance (OP).Practical implicationsThe framework will serve as a guiding tool to the management of the retail outlets to examine carefully the link among CSRP with other variables presented in the study and subsequently to the retail outlet performance. The retailers must be more focused on the expectations and demands of the customers concerning products and services for better growth of the firms.Originality/valueThe uniqueness of the study lies in “CSR practices enabled integrated model” to examine the performance of the organizations. The proposed theoretical model would add value to the existing literature to help the retailers in process of their performance improvement.
A design science approach to developing and evaluating items for the assessment of transversal professional competences
Authors: Fahrenbach Florian 
Published: December 2021

PurposeRelying on a design science paradigm, the purpose of this paper is to describe the development and evaluation of items for an ICT artefact that supports the assessment of transversal professional competences within the validation of prior learning (VPL). To do so, the authors build a conceptual bridge between the Occupational Information Network (O*NET) and the European Qualifications Framework (EQF).Design/methodology/approachDesign science research paradigm, in particular the participatory development of candidate items and their evaluation in a multi-stakeholder approach.FindingsThe authors find that a self-assessment of professional competences should be comprised of 160 items in order to cover the breadth and depth of the O*NET in the hierarchical taxonomy. Such quantity of items sufficiently builds a conceptual bridge between the O*NET and the; EQF.Practical implicationsWhen designing procedures for the VPL, it is imperative to bear in mind the purpose of the validation procedure, in order to determine relevant stakeholders and their needs in advance as well as the; required language proficiency of the assessment instrument.Social implicationsThe innovative value of this approach lies in the combination of an underlying hierarchical taxonomy with assessment items that are developed based on the qualification standards of different Austrian professions. Together with specific verbs that were adapted for each particular item, an innovative self-assessment is proposed. Thereby the authors aim to account for some of the mentioned shortcomings of the EQF.Originality/valueThis paper applies a design science paradigm to develop an ICT artefact that should support the VPL. By reflecting on the design process, the authors introduce a theoretical bridge between the O*NET and the EQF. Thereby the authors aim to account for some of the mentioned shortcomings of the EQF.