bluuebunny/crossref_metadata_2025_split huggingface dataset:
Heterogeneity and dynamics of ERK and Akt activation by G protein-coupled receptors depend on the activated heterotrimeric G proteins
Authors: Chavez-Abiega Sergei , Grönloh Max L.B. , Gadella T.W.J. , Bruggeman Frank J. , Goedhart J. 
Published: July 2021

ABSTRACTKinases are fundamental regulators of cellular functions and play key roles in GPCR-mediated signaling pathways. Kinase activities are generally inferred from cell lysates, hiding the heterogeneity of the individual cellular responses to extracellular stimuli. Here, we study the dynamics and heterogeneity of ERK and Akt in genetically identical cells in response to activation of endogenously expressed GPCRs. We use kinase translocation reporters, high-content imaging, automated segmentation and clustering methods to assess cell-to-cell signaling heterogeneity. We observed ligand-concentration dependent response kinetics to histamine, a2-adrenergic, and S1P receptor stimulation that varied between cells. By using G protein inhibitors, we observed that Gq mediated the ERK and Akt responses to histamine. In contrast, Gi was necessary for ERK and Akt activation in response to α2-adrenergic receptor activation. ERK and Akt were also strongly activated by S1P, showing high heterogeneity at the single cell level, especially for ERK. In all cases, the cellular heterogeneity was not explained by distinct pre-stimulation levels or saturation of the measured response. Cluster analysis of time-series derived from 68,000 cells obtained under the different conditions revealed several distinct populations of cells that display similar response dynamics. The single-cell ERK responses to histamine and brimonidine showed remarkably similar dynamics, despite the activation of different heterotrimeric G proteins. In contrast, the ERK response dynamics to S1P showed high heterogeneity, which was reduced by the inhibition of Gi. To conclude, we have set up an imaging and analysis strategy that reveals substantial cell-to-cell heterogeneity in kinase activity driven by GPCRs.Abstract Figure
Optogenetic actuator/ERK biosensor circuits identify MAPK network nodes that shape ERK dynamics
Authors: Dessauges Coralie , Mikelson Jan , Dobrzyński Maciej , Jacques Marc-Antoine , Frismantiene Agne , Gagliardi Paolo Armando , Khammash Mustafa , Pertz Olivier 
Published: July 2021

AbstractCombining single-cell measurements of ERK activity dynamics with perturbations provides insights into the MAPK network topology. We built circuits consisting of an optogenetic actuator to activate MAPK signaling and an ERK biosensor to measure single-cell ERK dynamics. This allowed us to conduct RNAi screens to investigate the role of 50 MAPK proteins in ERK dynamics. We found that the MAPK network is robust against most node perturbations. We observed that the ERK-RAF and the ERK-RSK2-SOS negative feedbacks operate simultaneously to regulate ERK dynamics. Bypassing the RSK2-mediated feedback, either by direct optogenetic activation of RAS, or by RSK2 perturbation, sensitized ERK dynamics to further perturbations. Similarly, targeting this feedback in a human ErbB2-dependent oncogenic signaling model increased the efficiency of a MEK inhibitor. The RSK2-mediated feedback is thus important for the ability of the MAPK network to produce consistent ERK outputs and its perturbation can enhance the efficiency of MAPK inhibitors.
Phytoplankton exudates provide full nutrition to a subset of accompanying heterotrophic bacteria via carbon, nitrogen and phosphorus allocation
Authors: Eigemann Falk , Rahav Eyal , Grossart Hans-Peter , Aharonovich Dikla , Sher Daniel , Vogts Angela , Voss Maren 
Published: July 2021

AbstractMarine bacteria rely on phytoplankton exudates as carbon sources (DOCp). Yet, it is unclear to what extent phytoplankton exudates also provide nutrients such as phytoplankton-derived N and P (DONp, DOPp). We address these questions by exudate addition experiments from the ubiquitous pico-cyanobacteriumProchlorococcusto contrasting ecosystems in the Eastern Mediterranean – a coastal and an open-ocean, oligotrophic station. Nutrient addition did not lower the incorporation of exudate DONp, nor did it reduce alkaline phosphatase activity, suggesting that bacterial communities are able to exclusively cover their nitrogen and phosphorus demands with organic forms provided by phytoplankton exudates. Approximately half of the cells in each ecosystem took up detectable amounts ofProchlorococcus-derived C and N, yet based on 16S rRNA sequencing different bacterial genera were responsible for the observed exudate utilization patterns. In the coastal community, several phylotypes ofAureimarina,PsychrosphaeraandGlaciecolaresponded positively to the addition of phytoplankton exudates, whereas phylotypes ofPseudoalteromonasincreased and dominated the open ocean communities. Together, our results strongly indicate that phytoplankton exudates provide coastal and open-ocean bacterial communities with organic carbon, nitrogen and phosphorus, and that phytoplankton exudate serve a full-fledged meal for specific members of the accompanying bacterial community in the nutrient-poor eastern Mediterranean.
Anti-arthralgic activity of the n-hexane extract (HTp) of yellow oleander seeds; Thevetia peruviana (Pers.) K. Schum
Authors: Odimegwu Joy Ifunanya , Olabisi Fatiha Oyebola 
Published: July 2021

ABSTRACTThevetia peruviana (Pers.) K.Schum. (Apocynaceae) seeds are known to possess cardioactive glycosides such as thevetin A, thevetin B, nerifolin etc. They are also used locally for general pain relief for which there is no scientific evidence to our knowledge. Arthralgia is regarded generally as pain without inflammation. It is endemic in the society and sufferers continue to imbibe pain relieving drugs in their tons all over the world. Analgesic activity test was carried out using the formalin-induced pain models, at 0.1g, 0.2g and 0.3g/kg doses of n-hexane extracts of Thevetia peruviana seeds (HTp) in Wistar mice. Diclofenac was used as positive control. Acute toxicity test was carried out at doses of 1000, 2500 and 5000 mg/kg weight of test subject. It was observed that HTp at concentrations of 0.1g, 0.2g and 0.3g/kg showed significant analgesic effect at compared to the control. The percentage inhibition observed was 29.60%, 44.80% and 50.72% for the early pain phase and 100% for the late pain phase respectively, indicating HTp’s NSAID-like property. HTp showed the highest percentage inhibition at 300 mg/kg (50.72 %) and significant (P<0.005) pain reduction. HTp did not produce any toxicity up to a dose of 5000 mg/kg weight which is very interesting as the seeds are known for their toxicity due to the cardiac glycoside presence. The results of the study suggest that HTp does indeed relieve pain significantly in a dose dependent manner, thus justifying its use in management of arthralgia.
Nitrate-regulated growth processes involve activation of gibberellin pathway
Authors: Camut Lucie , Gallova Barbora , Jilli Lucas , Sirlin-Josserand Mathilde , Carrera Esther , Sakvarelidze-Achard Lali , Zumsteg Julie , Heintz Dimitri , Ruffel Sandrine , Krouk Gabriel , Thomas Stephen G. , Hedden Peter , Phillips Andrew L. , Davière Jean-Michel , Achard Patrick 
Published: July 2021

AbstractNitrate, one of the main nitrogen (N) sources for crops, acts as a nutrient and key signaling molecule coordinating gene expression, metabolism and various growth processes throughout the plant life cycle. It is widely accepted that nitrate-triggered developmental programs cooperate with hormone synthesis and transport, to finely adapt plant architecture to N availability. Here, we report that nitrate, acting through its signaling pathway, promotes growth in Arabidopsis and wheat, in part by modulating the accumulation of gibberellin (GA)-regulated DELLA growth repressors. We show that nitrate reduces the abundance of DELLAs by increasing GA contents through activation of GA metabolism gene expression. Consistently, the growth restraint conferred by nitrate deficiency is partially rescued in global-DELLA mutant that lacks all DELLAs. At the cellular level, we show that nitrate enhances both cell proliferation and elongation in a DELLA-dependent and -independent manner, respectively. Our findings establish a connection between nitrate and GA signaling pathways that allow plants to adapt their growth to nitrate availability.
Resurrecting Golgi proteins to grasp Golgi ribbon formation and self-association under stress
Authors: Mendes Luis F. S. , Batista Mariana R. B. , Kava Emanuel , Bleicher Lucas , Micheletto Mariana C. , Costa-Filho Antonio J. 
Published: July 2021

AbstractThe Golgi complex is a membranous organelle located in the heart of the eukaryotic secretory pathway. A subfamily of the Golgi matrix proteins, called GRASPs, are key players in the stress-induced unconventional secretion, the Golgi dynamics during mitosis/apoptosis, and Golgi ribbon formation. The Golgi ribbon is vertebrate-specific and correlates with the appearance of two GRASP paralogs (GRASP55/GRASP65) and two coiled-coil Golgins (GM130/Golgin45), which interact with each otherin vivo. Although essential for the Golgi ribbon formation and the increase in Golgi structural complexity, the molecular details leading to their appearance only in this subphylum are still unknown. Moreover, despite the new functionalities supported by the GRASP paralogy, little is known about the structural and evolutionary differences between these paralogues. In this context, we used ancestor sequence reconstruction and several biophysical/biochemical approaches to assess the evolution of the GRASP structure, flexibility, and how they started anchoring their Golgin partners. Our data showed that the Golgins appeared in evolution and were anchored by the single GRASP ancestor beforegoraspgene duplication and divergence in Metazoans. After thegoraspdivergence, variations inside the GRASP binding pocket determined which paralogue would recruit each Golgin partner (GRASP55 with Golgin45 and GRASP65 with GM130). These interactions are responsible for the protein’s specific Golgi locations and the appearance of the Golgi ribbon. We also suggest that the capacity of GRASPs to form supramolecular structures is a long-standing feature, which likely affects GRASP’s participation as a trigger of the stress-induced secretory pathway.
Functional and comparative genomics reveals conserved noncoding sequences in the nitrogen-fixing clade
Authors: Pereira Wendell J. , Knaack Sara , Conde Daniel , Chakraborty Sanhita , Folk Ryan A. , Triozzi Paolo M. , Balmant Kelly M. , Dervinis Christopher , Schmidt Henry W. , Ané Jean-Michel , Roy Sushmita , Kirst Matias 
Published: July 2021

ABSTRACTNitrogen is one of the most inaccessible plant nutrients, but certain species have overcome this limitation by establishing symbiotic interactions with nitrogen-fixing bacteria in the root nodule. This root nodule symbiosis (RNS) is restricted to species within a single clade of angiosperms, suggesting a critical evolutionary event at the base of this clade, which has not yet been determined. While genes implicated in the RNS are present in most plant species (nodulating or not), gene sequence conservation alone does not imply functional conservation – developmental or phenotypic differences can arise from variation in the regulation of transcription. To identify putative regulatory sequences implicated in the evolution of RNS, we aligned the genomes of 25 species capable of nodulation. We detected 3,091 conserved noncoding sequences (CNS) in the nitrogen-fixing clade that are absent from outgroup species. Functional analysis revealed that chromatin accessibility of 452 CNS significantly correlates with the differential regulation of genes responding to lipo-chitooligosaccharides inMedicago truncatula. These included 38 CNS in proximity to 19 known genes involved in RNS. Five such regions are upstream ofMtCRE1,Cytokinin Response Element 1,required to activate a suite of downstream transcription factors necessary for nodulation inM. truncatula. Genetic complementation of aMtcre1mutant showed a significant association between nodulation and the presence of these CNS, when they are driving the expression of a functional copy ofMtCRE1. Conserved noncoding sequences, therefore, may be required for the regulation of genes controlling the root nodule symbiosis inM. truncatula.
Polar accumulation of pyoverdin and exit from stationary phase
Authors: Moreno-Fenoll Clara , Ardré Maxime , Rainey Paul B. 
Published: July 2021

AbstractPyoverdin is a water-soluble metal-chelator synthesized by members of the genusPseudomonasand used for the acquisition of insoluble ferric iron. Although freely diffusible in aqueous environments, preferential dissemination of pyoverdin among adjacent cells, fine-tuning of intracellular siderophore concentrations, and fitness advantages to pyoverdin-producing versus nonproducing cells, indicate control of location and release. Here, using time-lapse fluorescence microscopy to track single cells in growing microcolonies ofPseudomonas fluorescensSBW25, we show accumulation of pyoverdin at cell poles. Accumulation occurs on cessation of cell growth, is achieved by cross-feeding in pyoverdin-nonproducing mutants and is reversible. Moreover, accumulation coincides with localization of a fluorescent periplasmic reporter, suggesting that pyoverdin accumulation at cell poles is part of the general cellular response to starvation. Compatible with this conclusion is absence of non-accumulating phenotypes in a range of pyoverdin mutants. Analysis of the performance of pyoverdin-producing and nonproducing cells under conditions promoting polar accumulation shows an advantage to accumulation on resumption of growth after stress. Examination of pyoverdin polar accumulation in a multispecies community and in a range of laboratory and natural species ofPseudomonas, includingP. aeruginosaPAO1 andP. putidaKT2440, confirms that the phenotype is characteristic ofPseudomonas.
Ribosomal protein L23 drives the metastasis of hepatocellular carcinoma via upregulating MMP9
Authors: Yang Minli , Zhou Yujiao , Deng Haijun , Zhou Hongzhong , Cheng Shengtao , Zhang Dapeng , He Xin , Mai Li , Chen Yao , Li Fan , Chen Juan 
Published: July 2021

AbstractHepatocellular carcinoma (HCC) is one of the leading causes of cancer-related deaths globally and tumor metastasis is one of the major causes of high mortality. To identify novel molecules contributing to HCC metastasis is critical to understanding the underlining mechanism of cancer metastasis. Here, combining the analyze based on published database and liver tissues from HCC patients, we identified that RNA binding protein L23 (RPL23) as a tumor metastasis driver in HCC. RPL23 was elevated in HCC and closely related to poor clinical outcomes. Furthermore, RPL23 depletion inhibited HCC cell proliferation, migration and invasion, while RPL23 overexpression promoted HCC cell metastasis. Mechanistically, RPL23 positively regulated MMP9 expression by stabilizing its mRNA. And increased MMP9 is involved in RPL23-mediated HCC metastasis. Importantly, RPL23 silencing reduced tumor growth and metastasis in vivo. In summary, we identified that RPL23 play an important role in HCC metastasis in an MMP9-dependent manner and may be a novel potential therapeutic target for HCC tumorigenesis and metastasis.
Disruption of the TCA cycle reveals an ATF4-dependent integration of redox and amino acid metabolism
Authors: Ryan Dylan G. , Yang Ming , Prag Hiran A. , Blanco Giovanny Rodriguez , Nikitopoulou Efterpi , Segarra-Mondejar Marc , Powell Christopher A. , Young Tim , Burger Nils , Miljkovic Jan Lj. , Minczuk Michal , Murphy Michael P. , von Kriegsheim Alexander , Frezza Christian 
Published: July 2021

SummaryThe Tricarboxylic Acid Cycle (TCA) cycle is arguably the most critical metabolic cycle in physiology and exists as an essential interface coordinating cellular metabolism, bioenergetics, and redox homeostasis. Despite decades of research, a comprehensive investigation into the consequences of TCA cycle dysfunction remains elusive. Here, we targeted two TCA cycle enzymes, fumarate hydratase (FH) and succinate dehydrogenase (SDH), and combined metabolomics, transcriptomics, and proteomics analyses to fully appraise the consequences of TCA cycle inhibition (TCAi) in kidney epithelial cells. Our comparative approach shows that TCAi elicits a convergent rewiring of redox and amino acid metabolism dependent on the activation of ATF4 and the integrated stress response (ISR). Furthermore, we also uncover a divergent metabolic response, whereby acute FHi, but not SDHi, can maintain asparagine levels via reductive carboxylation and maintenance of cytosolic aspartate synthesis. Our work highlights an important interplay between the TCA cycle, redox biology and amino acid homeostasis.HighlightsTCA cycle inhibition promotes GSH synthesis and impairs de novo aspartate and proline synthesisDisruption of mitochondrial thiol redox homeostasis phenocopies TCA cycle inhibition by promoting GSH synthesis and impairing proline and aspartate synthesisAcute FHi, but not SDHi, can maintain asparagine levels via reductive carboxylation and maintenance of cytosolic aspartate synthesisTCA cycle inhibition mimics an amino acid deprivation-type response and activates ATF4 via the integrated stress response to maintain redox and amino acid homeostasis
Average stride length and stride rate of Thoroughbreds and Quarter Horses during ‘Sprint’ and ‘Classic’ races
Authors: Vergara-Hernandez Fernando B. , Nielsen Brian D. , Robison Cara I. , Fabus Taylor A. , Kompare Jasmin L. , LeCompte Lasic Rebecca A. , Colbath Aimee C. 
Published: July 2021

AbstractThe main factors influencing speed in athletes are stride length (SL) and stride rate (SR). However, conflict remains whether SL or SR is the key determinant of higher speeds. Quarter Horses (QH) generally reach higher speeds in their races than do Thoroughbreds (TB). However, the influence of SL and SR on this greater speed is unclear. Therefore, the main objective of this study was to compare SL and SR in QH and TB raced in short (sprint) and long (classic) distances. We hypothesized that QH have a higher SR in comparison to TB, and SR decreases as distance increases. Two race distances were analyzed for each breed: QH races of 100.6 and 402.3 m, and TB races of 1,207.0 m and 2,011.7 m. Data from twenty horses were obtained, consisting of five horses from each race distance (10 QH and 10 TB). Five individuals watched recordings of each race three times counting the number of strides taken by each winning horse. The SR was calculated using the average number of strides over a given race duration, and SL was determined by calculating the total number of strides over the distance covered. Speed was calculated dividing the distance by the time of the winning horse. The PROC Mixed Procedure was used to identify statistical differences between breeds, and between distances within the same breed. Results showed that although the SL of the TB was longer in comparison with the QH (P<0.001), the average SR in QH was higher than in TB (2.88 vs 2.34 + 0.03 strides/s; P<0.001). Further, QH classic distance demonstrated a faster speed than TB at either distance (P<0.001). In conclusion, QH achieve a higher SR in comparison to TB (between 14-20% more than TB), confirming the importance of SR in achieving high racing speeds.
Host-symbiont stress response to lack-of-sulfide in the giant ciliate mutualism
Authors: Espada-Hinojosa Salvador , Drexel Judith , Kesting Julia , Kniha Edwin , Pifeas Iason , Schuster Lukas , Volland Jean-Marie , Zambalos Helena C. , Bright Monika 
Published: July 2021

AbstractThe thiotrophic mutualism between the sulfur-oxidizing, chemoautotrophic (thiotrophic) bacterial ectosymbiontCandidatusThiobius zoothamnicola and the giant ciliateZoothamnium niveumthrives in a variety of shallow-water marine environments with highly fluctuating sulfide emission. To persist over time both partners must reproduce and ensure symbiont transmission prior cessation of sulfide, fueling the symbiont’s carbon fixation and host nourishment. We experimentally investigated the response of this mutualism to waning of sulfide. We found that colonies followed the r-strategy and released initially present but also newly produced macrozooids until death. A fraction of middle-sized longer-lived colonies were particularly proficient in producing and releasing swarmers. The symbionts on the colonies proliferated less and became larger and more rod-shaped under oxic conditions compared to symbionts from freshly collected colonies exposed to sulfide and oxygen. The symbiont monolayer was highly disturbed with epigrowth of other microbes and loss of symbionts that were subsequently found in the experimental seawater. We conclude that both partners’ response to cessation of sulfide emission was remarkably fast. The colony experienced death within two days but host reproduction through swarmers carrying the symbiont ensured the continuation of the association.
Perinatal maternal chronic exposure to dibutyl phthalate promotes visceral obesity in adult female offspring
Authors: Zhou Kunyan , Cheng Ran , Yang Meina , Shen Xiaoyang , Luo Xiaoyan , Ma Li , Xu Liangzhi , Zhang Jing 
Published: July 2021

AbstractIntroductionMaternal exposure to dibutyl phthalate (DBP) may result in glucolipid dysfunction in female offspring. However, the underlying mechanisms remain elusive. We hypothesized that chronic maternal DBP exposure could induce abnormal metabolism of glucolipid.Materials and methodsSprague-Dawley rats were intraperitoneally injected with different doses of DBP, estradiol, and corn oil from gestational day 7 until the end of lactation. The weights, visceral fat percentage, serum lipid, insulin and glucose, protein levels of PI3K signal pathway in muscle were detected in F1 female offspring.ResultsAlthough the birth weight of F1 female offspring was not different among groups, the weights were heavier in DBP groups from postnatal day 7 to adult (P<0.001). The visceral adipose percentage in adult female offspring was increased by perinatal exposure to DBP (P<0.001). Decreased serum levels of triglyceride (P<0.0001), fasting glucose (P=0.004), prolactin (P=0.006), HOMA-IR (P=0.014) were found in female offspring exposed to DBP, but no difference for fasting insulin, total cholesterol, adiponectin. Increased protein levels of p-AKT, but decreased PTEN and GPR30 were observed in muscle of female offspring in DBP group, but without significant difference. None difference was observed for the protein levels of PI3K, AKT, GLUT4, InsR and IRS-1.ConclusionMaternal perinatal exposure to DBP induced obesity and accumulation of visceral adipose tissue for the adult female offspring. Serum glucolipid and local signal transduction of PTEN/PI3K/AKT pathway in muscle were not adversely affected by perinatal exposure to DBP for adult female offspring.