scholarly journals Neuronal regulated ire-1-dependent mRNA decay controls germline differentiation in Caenorhabditis elegans

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Mor Levi-Ferber ◽  
Rewayd Shalash ◽  
Adrien Le-Thomas ◽  
Yehuda Salzberg ◽  
Maor Shurgi ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Caenorhabditis Elegans ◽  
Er Stress ◽  
Cell Fate ◽  
Germ Cells ◽  
Mrna Decay ◽  
Neuronal Circuit ◽  
Animal Physiology ◽  
Molecular Events ◽  
Germline Differentiation

Understanding the molecular events that regulate cell pluripotency versus acquisition of differentiated somatic cell fate is fundamentally important. Studies in Caenorhabditis elegans demonstrate that knockout of the germline-specific translation repressor gld-1 causes germ cells within tumorous gonads to form germline-derived teratoma. Previously we demonstrated that endoplasmic reticulum (ER) stress enhances this phenotype to suppress germline tumor progression(Levi-Ferber et al., 2015). Here, we identify a neuronal circuit that non-autonomously suppresses germline differentiation and show that it communicates with the gonad via the neurotransmitter serotonin to limit somatic differentiation of the tumorous germline. ER stress controls this circuit through regulated inositol requiring enzyme-1 (IRE-1)-dependent mRNA decay of transcripts encoding the neuropeptide FLP-6. Depletion of FLP-6 disrupts the circuit’s integrity and hence its ability to prevent somatic-fate acquisition by germline tumor cells. Our findings reveal mechanistically how ER stress enhances ectopic germline differentiation and demonstrate that regulated Ire1-dependent decay can affect animal physiology by controlling a specific neuronal circuit.

scholarly journals Neuronal regulated Ire1-dependent mRNA decay controls germline differentiation in C. elegans

2020 ◽  
Author(s):  
Mor Levi-Ferber ◽  
Rewayd Shalash ◽  
Adrien Le-Thomas ◽  
Yehuda Salzberg ◽  
Maor Shurgi ◽  
...  
Keyword(s):  
Er Stress ◽  
Tumor Cells ◽  
Cell Fate ◽  
Germ Cells ◽  
Mrna Decay ◽  
Neuronal Circuit ◽  
C Elegans ◽  
Animal Physiology ◽  
Molecular Events ◽  
Germline Differentiation

Understanding the molecular events that regulate cell pluripotency versus acquisition of differentiated somatic cell fate is fundamentally important. Studies in C. elegans demonstrate that knockout of the germline-specific translation repressor gld-1, causes germ cells within tumorous gonads to form germline-derived teratoma. Previously we demonstrated that ER stress enhances this phenotype to suppress germline tumor progression (Levi-Ferber M, 2015). Here, we identify a neuronal circuit that non-autonomously suppresses germline differentiation, and show that it communicates with the gonad via the neurotransmitter serotonin to limit somatic differentiation of the tumorous germline. ER stress controls this circuit through regulated IRE-1-dependent mRNA decay of transcripts encoding the neuropeptide FLP-6. Depletion of FLP-6 disrupts the circuit's integrity and hence its ability to prevent somatic-fate acquisition by germline tumor cells. Our findings reveal mechanistically how ER stress enhances ectopic germline differentiation, and demonstrate that RIDD can affect animal physiology by controlling a specific neuronal circuit.

scholarly journals Crosstalk between endoplasmic reticulum stress and oxidative stress: a dynamic duo in multiple myeloma

2021 ◽  
Author(s):  
Sinan Xiong ◽  
Wee-Joo Chng ◽  
Jianbiao Zhou
Keyword(s):  
Oxidative Stress ◽  
Multiple Myeloma ◽  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Cell Fate ◽  
Stress Responses ◽  
Plasma Cells ◽  
Reactive Oxygen Species Generation ◽  
Future Research ◽  
And Oxidative Stress

AbstractUnder physiological and pathological conditions, cells activate the unfolded protein response (UPR) to deal with the accumulation of unfolded or misfolded proteins in the endoplasmic reticulum. Multiple myeloma (MM) is a hematological malignancy arising from immunoglobulin-secreting plasma cells. MM cells are subject to continual ER stress and highly dependent on the UPR signaling activation due to overproduction of paraproteins. Mounting evidence suggests the close linkage between ER stress and oxidative stress, demonstrated by overlapping signaling pathways and inter-organelle communication pivotal to cell fate decision. Imbalance of intracellular homeostasis can lead to deranged control of cellular functions and engage apoptosis due to mutual activation between ER stress and reactive oxygen species generation through a self-perpetuating cycle. Here, we present accumulating evidence showing the interactive roles of redox homeostasis and proteostasis in MM pathogenesis and drug resistance, which would be helpful in elucidating the still underdefined molecular pathways linking ER stress and oxidative stress in MM. Lastly, we highlight future research directions in the development of anti-myeloma therapy, focusing particularly on targeting redox signaling and ER stress responses.

scholarly journals Genetic control of programmed cell death in the Caenorhabditis elegans hermaphrodite germline

Development ◽  
1999 ◽  
Vol 126 (5) ◽  
pp. 1011-1022 ◽  
Author(s):  
T.L. Gumienny ◽  
E. Lambie ◽  
E. Hartwieg ◽  
H.R. Horvitz ◽  
M.O. Hengartner
Keyword(s):  
Cell Death ◽  
Caenorhabditis Elegans ◽  
Germ Cell ◽  
Somatic Cell ◽  
Cell Fate ◽  
Germ Cells ◽  
Mapk Pathway ◽  
Apoptotic Cell ◽  
C Elegans ◽  
Pathway Activation

Development of the nematode Caenorhabditis elegans is highly reproducible and the fate of every somatic cell has been reported. We describe here a previously uncharacterized cell fate in C. elegans: we show that germ cells, which in hermaphrodites can differentiate into sperm and oocytes, also undergo apoptotic cell death. In adult hermaphrodites, over 300 germ cells die, using the same apoptotic execution machinery (ced-3, ced-4 and ced-9) as the previously described 131 somatic cell deaths. However, this machinery is activated by a distinct pathway, as loss of egl-1 function, which inhibits somatic cell death, does not affect germ cell apoptosis. Germ cell death requires ras/MAPK pathway activation and is used to maintain germline homeostasis. We suggest that apoptosis eliminates excess germ cells that acted as nurse cells to provide cytoplasmic components to maturing oocytes.

The fog-3 gene and regulation of cell fate in the germ line of Caenorhabditis elegans.

Genetics ◽  
1995 ◽  
Vol 139 (2) ◽  
pp. 561-577 ◽  
Author(s):  
R E Ellis ◽  
J Kimble
Keyword(s):  
Caenorhabditis Elegans ◽  
Germ Cell ◽  
Sexual Identity ◽  
Cell Fate ◽  
Germ Cells ◽  
Regulatory Network ◽  
Germ Line ◽  
The Other ◽  
Nematode Caenorhabditis Elegans ◽  
Inhibitory Interactions

Abstract In the nematode Caenorhabditis elegans, germ cells normally adopt one of three fates: mitosis, spermatogenesis or oogenesis. We have identified and characterized the gene fog-3, which is required for germ cells to differentiate as sperm rather than as oocytes. Analysis of double mutants suggests that fog-3 is absolutely required for spermatogenesis and acts at the end of the regulatory hierarchy controlling sex determination for the germ line. By contrast, mutations in fog-3 do not alter the sexual identity of other tissues. We also have characterized the null phenotype of fog-1, another gene required for spermatogenesis; we demonstrate that it too controls the sexual identity of germ cells but not of other tissues. Finally, we have studied the interaction of these two fog genes with gld-1, a gene required for germ cells to undergo oogenesis rather than mitosis. On the basis of these results, we propose that germ-cell fate might be controlled by a set of inhibitory interactions among genes that specify one of three fates: mitosis, spermatogenesis or oogenesis. Such a regulatory network would link the adoption of one germ-cell fate to the suppression of the other two.

RyR1-mediated moderate endoplasmic reticulum stress is required for myogenic differentiation of myoblasts

2021 ◽  
Author(s):  
Kai Qiu ◽  
Yubo Wang ◽  
Doudou Xu ◽  
Linjuan He ◽  
Xin Zhang ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Cell Fate ◽  
Muscle Development ◽  
Myogenic Differentiation ◽  
C2c12 Cells ◽  
Stress Signaling ◽  
Congenital Myopathies ◽  
Myotube Formation

Abstract BackgroundCytosolic Ca2+ plays vital roles in myogenesis and muscle development. Key mutations of ryanodine receptor 1 (RyR1), a major Ca2+ release channel of endoplasmic reticulum (ER), are main causes of severe congenital myopathies. The role of RyR1 in myogenic differentiation has attracted intense research interest, however, it remains unclear. MethodsThis study employed RyR1-knockdown myoblasts and CRISPR/Cas9-based RyR1-knockout myoblasts cells to explore the role of RyR1 in myogenic differentiation, myotube formation as well as the potential mechanism of RyR1-related myopathies.ResultsCytoplasmic Ca2+ concentration was significantly elevated during myogenic differentiation of both primary myogenic cells and myoblasts C2C12 cells, accompanied with a dramatic increase in RyR1 expression and resultant ER stress. Inhibition of RyR1 by siRNA-mediated silence or chemical inhibitor, dantrolene, significantly reduced cytosolic Ca2+, alleviated ER stress, and blocked multinucleated myotube formation. Moderate activation of ER stress effectively relieved myogenic differentiation stagnation induced by RyR1 suppression and demonstrated that RyR1 modulates myogenic differentiation via activation of Ca2+ -induced ER stress signaling. RyR1 knockout-induced Ca2+ leakage led to severe ER stress and excessive unfolded protein response, and drove cell fate from differentiation into apoptosis. ConclusionsTherefore, we concluded that dramatic increase in RyR1 expression is required for myogenic differentiation, and RyR1-mediated Ca2+ release leading to the activation of ER stress signaling serves a double-edged sword role during myogenic differentiation. This study contributes to a novel understanding of the role of RyR1 in muscle development and related congenital myopathies, and provides a potential target for regulation of muscle regeneration and tissue engineering.

scholarly journals Protective effect of paraoxonase-2 against endoplasmic reticulum stress-induced apoptosis is lost upon disturbance of calcium homoeostasis

2008 ◽  
Vol 416 (3) ◽  
pp. 395-405 ◽  
Author(s):  
Sven Horke ◽  
Ines Witte ◽  
Petra Wilgenbus ◽  
Sebastian Altenhöfer ◽  
Maximilian Krüger ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Protein Modification ◽  
Caspase 3 ◽  
Defence Mechanisms ◽  
Protective Function ◽  
Protein Levels ◽  
Molecular Events ◽  
Induced Apoptosis ◽  
Cellular Defence

PON2 (paraoxonase-2) is a ubiquitously expressed antioxidative protein which is largely found in the ER (endoplasmic reticulum). Addressing the cytoprotective functions of PON2, we observed that PON2 overexpression provided significant resistance to ER-stress-induced caspase 3 activation when the ER stress was induced by interference with protein modification (by tunicamycin or dithiothreitol), but not when ER stress was induced by disturbance of Ca2+ homoeostasis (by thapsigargin or A23187). When analysing the underlying molecular events, we found an activation of the PON2 promoter in response to all tested ER-stress-inducing stimuli. However, only tunicamycin and dithiothreitol resulted in increased PON2 mRNA and protein levels. In contrast, when ER stress was caused by thapsigargin or A23187, we observed a Ca2+-dependent active degradation of PON2 mRNA, elicited by its 5′-untranslated region. In addition, thapsigargin and A23187 also induced PON2 protein degradation by a Ca2+-dependent calpain-mediated mechanism. Thus we provide evidence that independent mechanisms mediate the degradation of PON2 mRNA and protein after disturbance of Ca2+ homoeostasis. Furthermore, because Ca2+-disturbance induces ER stress, but abrogates the otherwise protective function of PON2 against ER-stress-induced apoptosis, we propose that the underlying cause of ER stress determines the efficacy of putative cellular defence mechanisms.

scholarly journals Pancreatic eukaryotic initiation factor-2α kinase (PEK) homologues in humans, Drosophila melanogaster and Caenorhabditis elegans that mediate translational control in response to endoplasmic reticulum stress

2000 ◽  
Vol 346 (2) ◽  
pp. 281-293 ◽  
Author(s):  
Ruchira SOOD ◽  
Amy C. PORTER ◽  
Kun MA ◽  
Lawrence A. QUILLIAM ◽  
Ronald C. WEK
Keyword(s):  
Endoplasmic Reticulum ◽  
Drosophila Melanogaster ◽  
Caenorhabditis Elegans ◽  
Er Stress ◽  
Translational Control ◽  
Mammalian Cells ◽  
Transmembrane Protein ◽  
Initiation Factor ◽  
Eukaryotic Initiation Factor ◽  
Α Subunit

In response to different cellular stresses, a family of protein kinases regulates translation by phosphorylation of the α subunit of eukaryotic initiation factor-2 (eIF-2α). Recently, we identified a new family member, pancreatic eIF-2α kinase (PEK) from rat pancreas. PEK, also referred to as RNA-dependent protein kinase (PKR)-like endoplasmic reticulum (ER) kinase (PERK) is a transmembrane protein implicated in translational control in response to stresses that impair protein folding in the ER. In this study, we identified and characterized PEK homologues from humans, Drosophila melanogaster and Caenorhabditis elegans. Expression of human PEK mRNA was found in over 50 different tissues examined, with highest levels in secretory tissues. In mammalian cells subjected to ER stress, we found that elevated eIF-2α phosphorylation was coincident with increased PEK autophosphorylation and eIF-2α kinase activity. Activation of PEK was abolished by deletion of PEK N-terminal sequences located in the ER lumen. To address the role of C. elegans PEK in translational control, we expressed this kinase in yeast and found that it inhibits growth by hyperphosphorylation of eIF-2α and inhibition of eIF-2B. Furthermore, we found that vaccinia virus K3L protein, an inhibitor of the eIF-2α kinase PKR involved in an anti-viral defence pathway, also reduced PEK activity. These results suggest that decreased translation initiation by PEK during ER stress may provide the cell with an opportunity to remedy the folding problem prior to introducing newly synthesized proteins into the secretory pathway.

scholarly journals Broadly conserved roles of TMEM131 family proteins in intracellular collagen assembly and secretory cargo trafficking

2020 ◽  
Vol 6 (7) ◽  
pp. eaay7667 ◽  
Author(s):  
Zhe Zhang ◽  
Meirong Bai ◽  
Guilherme Oliveira Barbosa ◽  
Andrew Chen ◽  
Yuehua Wei ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Rna Interference ◽  
Caenorhabditis Elegans ◽  
Stress Response ◽  
Er Stress ◽  
C Elegans ◽  
Er Stress Response ◽  
Evolutionarily Conserved ◽  
Human Disorders ◽  
Intracellular Collagen

Collagen is the most abundant protein in animals. Its dysregulation contributes to aging and many human disorders, including pathological tissue fibrosis in major organs. How premature collagen proteins in the endoplasmic reticulum (ER) assemble and route for secretion remains molecularly undefined. From an RNA interference screen, we identified an uncharacterized Caenorhabditis elegans gene tmem-131, deficiency of which impairs collagen production and activates ER stress response. We find that amino termini of human TMEM131 contain bacterial PapD chaperone–like domains, which recruit premature collagen monomers for proper assembly and secretion. Carboxy termini of TMEM131 interact with TRAPPC8, a component of the TRAPP tethering complex, to drive collagen cargo trafficking from ER to the Golgi. We provide evidence that previously undescribed roles of TMEM131 in collagen recruitment and secretion are evolutionarily conserved in C. elegans, Drosophila, and humans.

scholarly journals BiP Availability Distinguishes States of Homeostasis and Stress in the Endoplasmic Reticulum of Living Cells

2010 ◽  
Vol 21 (12) ◽  
pp. 1909-1921 ◽  
Author(s):  
Chun Wei Lai ◽  
Deborah E. Aronson ◽  
Erik Lee Snapp
Keyword(s):  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Protein Misfolding ◽  
Single Cells ◽  
Cell Types ◽  
Secretory Protein ◽  
Misfolded Proteins ◽  
Secretory Proteins ◽  
Molecular Events ◽  
The Unfolded Protein Response

Accumulation of misfolded secretory proteins causes cellular stress and induces the endoplasmic reticulum (ER) stress pathway, the unfolded protein response (UPR). Although the UPR has been extensively studied, little is known about the molecular changes that distinguish the homeostatic and stressed ER. The increase in levels of misfolded proteins and formation of complexes with chaperones during ER stress are predicted to further crowd the already crowded ER lumen. Surprisingly, using live cell fluorescence microscopy and an inert ER reporter, we find the crowdedness of stressed ER, treated acutely with tunicamycin or DTT, either is comparable to homeostasis or significantly decreases in multiple cell types. In contrast, photobleaching experiments revealed a GFP-tagged variant of the ER chaperone BiP rapidly undergoes a reversible quantitative decrease in diffusion as misfolded proteins accumulate. BiP mobility is sensitive to exceptionally low levels of misfolded protein stressors and can detect intermediate states of BiP availability. Decreased BiP availability temporally correlates with UPR markers, but restoration of BiP availability correlates less well. Thus, BiP availability represents a novel and powerful tool for reporting global secretory protein misfolding levels and investigating the molecular events of ER stress in single cells, independent of traditional UPR markers.

scholarly journals Endoplasmic Reticulum Stress and Neurodegeneration in Rats Neonatally Infected with Borna Disease Virus

2006 ◽  
Vol 80 (17) ◽  
pp. 8613-8626 ◽  
Author(s):  
B. L. Williams ◽  
W. I. Lipkin
Keyword(s):  
Quality Control ◽  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Cell Fate ◽  
Disease Virus ◽  
Critical Determinant ◽  
Er Quality Control ◽  
Borna Disease Virus ◽  
Control Signals ◽  
Borna Disease

ABSTRACT Borna disease virus infection of neonatal rats results in a characteristic behavioral syndrome and apoptosis of subsets of neurons in the hippocampus and cerebellum (neonatal Borna disease [NBD]). The cellular mechanisms leading to neurodevelopmental damage in NBD have not been fully elucidated. Insights into this model may have general implications for understanding the pathogenesis of virus-associated neurodevelopmental damage. Here we report the presence of endoplasmic reticulum (ER) stress markers and activation of the unfolded protein response in the NBD hippocampus and cerebellum. Specific findings included enhanced PERK-mediated phosphorylation of eif2α and concomitant regulation of ATF4 translation; IRE1-mediated splicing of XBP1 mRNA; and cleavage of the ATF6 protein in NBD rat brains. We found evidence for regional and cell type-specific divergence in the expression of ER stress-induced proapoptotic and quality control signals. Our results demonstrate that ER stress induction in death-susceptible Purkinje neurons in NBD is associated with the expression of the proapoptotic molecule CHOP in the absence of compensatory expression of the ER quality control molecules Bip and protein disulfide isomerase. In contrast, ER stress in death-resistant astrocytes is associated with complementary expression of CHOP and ER quality control signals. These results implicate an imbalance between ER stress-mediated apoptosis and survival signaling as a critical determinant of neural cell fate in NBD.

Sign in / Sign up

Export Citation Format

Share Document