scholarly journals picd-1, a gene that encodes CABIN1 domain-containing protein, interacts with pry-1/Axin to regulate multiple processes in Caenorhabditis elegans

2021 ◽  
Author(s):  
Avijit Mallick ◽  
Shane K. B. Taylor ◽  
Sakshi Mehta ◽  
Bhagwati P. Gupta
Keyword(s):  
Stress Response ◽  
Essential Role ◽  
Family Members ◽  
Transcriptome Profiling ◽  
Scaffolding Protein ◽  
Dependent Manner ◽  
C Elegans ◽  
Downstream Effectors ◽  
Cellular Components

ABSTRACTAXIN family members control diverse biological processes in eukaryotes. As a scaffolding protein, AXIN facilitates interactions between cellular components and provides specificity to signaling pathways. Despite its crucial roles in metazoans and discovery of a large number of family members, the mechanism of AXIN function is not very well understood. The C. elegans AXIN homolog PRY-1 provides a powerful tool to identify interacting genes and downstream effectors that function in a conserved manner to regulate AXIN-mediated signaling. Previous work demonstrated pry-1’s essential role in developmental processes such as reproductive system, seam cells, and a P lineage cell P11.p. More recently, our lab carried out a transcriptome profiling of pry-1 mutant and uncovered the essential role of the gene in lipid metabolism, stress response, and aging. In this study, we have extended the work on pry-1 by reporting a novel interacting gene picd-1 (pry-1-interacting CABIN1 domain containing). Our findings have revealed that picd-1 plays an essential role in C. elegans and is involved in several pry-1-mediated processes including regulation of stress response and lifespan maintenance. In support of this, picd-1 expression overlaps with pry-1 in multiple tissues throughout the lifespan of animals. Further experiments showed that picd-1 inhibits CREB-regulated transcriptional coactivator homolog CRTC-1 function, which promotes longevity in a calcineurin-dependent manner. These data provide evidence for an essential role of the CABIN1 domain protein PICD-1 in mediating PRY-1 signaling in C. elegans.

scholarly journals Syndecan Transmembrane Domain Specifically Regulates Downstream Signaling Events of the Transmembrane Receptor Cytoplasmic Domain

2021 ◽  
Vol 22 (15) ◽  
pp. 7918
Author(s):  
Jisun Hwang ◽  
Bohee Jang ◽  
Ayoung Kim ◽  
Yejin Lee ◽  
Joonha Lee ◽  
...  
Keyword(s):  
Transmembrane Domain ◽  
Growth Factor Receptor ◽  
Cytoplasmic Domain ◽  
Nih3t3 Cells ◽  
C Elegans ◽  
Downstream Signaling ◽  
Downstream Effectors ◽  
Signaling Events

Despite the known importance of the transmembrane domain (TMD) of syndecan receptors in cell adhesion and signaling, the molecular basis for syndecan TMD function remains unknown. Using in vivo invertebrate models, we found that mammalian syndecan-2 rescued both the guidance defects in C. elegans hermaphrodite-specific neurons and the impaired development of the midline axons of Drosophila caused by the loss of endogenous syndecan. These compensatory effects, however, were reduced significantly when syndecan-2 dimerization-defective TMD mutants were introduced. To further investigate the role of the TMD, we generated a chimera, 2eTPC, comprising the TMD of syndecan-2 linked to the cytoplasmic domain of platelet-derived growth factor receptor (PDGFR). This chimera exhibited SDS-resistant dimer formation that was lost in the corresponding dimerization-defective syndecan-2 TMD mutant, 2eT(GL)PC. Moreover, 2eTPC specifically enhanced Tyr 579 and Tyr 857 phosphorylation in the PDGFR cytoplasmic domain, while the TMD mutant failed to support such phosphorylation. Finally, 2eTPC, but not 2eT(GL)PC, induced phosphorylation of Src and PI3 kinase (known downstream effectors of Tyr 579 phosphorylation) and promoted Src-mediated migration of NIH3T3 cells. Taken together, these data suggest that the TMD of a syndecan-2 specifically regulates receptor cytoplasmic domain function and subsequent downstream signaling events controlling cell behavior.

Cellular Samurai: katanin and the severing of microtubules

2000 ◽  
Vol 113 (16) ◽  
pp. 2821-2827 ◽  
Author(s):  
L. Quarmby
Keyword(s):  
Epithelial Cells ◽  
Essential Role ◽  
Aaa Atpase ◽  
C Elegans ◽  
Microtubule Severing ◽  
Biochemical Studies ◽  
New Evidence

Recent biochemical studies of the AAA ATPase, katanin, provide a foundation for understanding how microtubules might be severed along their length. These in vitro studies are complemented by a series of recent reports of direct in vivo observation of microtubule breakage, which indicate that the in vitro phenomenon of catalysed microtubule severing is likely to be physiological. There is also new evidence that microtubule severing by katanin is important for the production of non-centrosomal microtubules in cells such as neurons and epithelial cells. Although it has been difficult to establish the role of katanin in mitosis, new genetic evidence indicates that a katanin-like protein, MEI-1, plays an essential role in meiosis in C. elegans. Finally, new proteins involved in the severing of axonemal microtubules have been discovered in the deflagellation system of Chlamydomonas.

scholarly journals Autophagosomes fuse to phagosomes and play important roles in the degradation of apoptotic cells in Caenorhabditis elegans

2021 ◽  
Author(s):  
Omar Pena-Ramos ◽  
Lucia Chiao ◽  
Xianghua Liu ◽  
Tianyou Yao ◽  
Henry He ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Small Gtpase ◽  
Apoptotic Cells ◽  
Phagosome Maturation ◽  
Double Membrane ◽  
C Elegans ◽  
Intracellular Organelles ◽  
Intracellular Vesicles ◽  
Cellular Components

Autophagosomes are double-membrane intracellular vesicles that degrade protein aggregates, intracellular organelles, and other cellular components. In the nematode Caenorhabditis elegans, 113 somatic cells undergo apoptosis during embryogenesis and are engulfed and degraded by their neighboring cells. We discovered a novel role of autophagosomes in facilitating the degradation of apoptotic cells in C. elegans embryos using a real-time imaging technique. Specifically, double-membrane autophagosomes in engulfing cells are recruited to the surfaces of phagosomes containing apoptotic cells and subsequently fuse to phagosomes, allowing the inner membrane to enter the phagosomal lumen. Mutants defective in the production of autophagosomes display significant delays in the degradation of apoptotic cells, demonstrating the important contribution of autophagosomes to this process. The signaling pathway led by the phagocytic receptor CED-1, CED-1s adaptor CED-6, and the large GTPase dynamin (DYN-1) promote the recruitment of autophagosomes to phagosomes. Moreover, the subsequent fusion of autophagosomes with phagosomes requires the functions of the small GTPase RAB-7 and the HOPS complex. Our findings reveal that, unlike the single-membrane, LC3- associated phagocytosis (LAP) vesicles reported for mammalian phagocytes, canonical autophagosomes function in the clearance of C. elegans apoptotic cells. These findings add autophagosomes to the collection of intracellular organelles that contribute to phagosome maturation, identify novel crosstalk between the autophagy and phagosome maturation pathways, and discover the upstream factors that initiate this crosstalk.

scholarly journals Caenorhabditits elegans LRK-1 and PINK-1 Act Antagonistically in Stress Response and Neurite Outgrowth

2009 ◽  
Vol 284 (24) ◽  
pp. 16482-16491 ◽  
Author(s):  
Julia Sämann ◽  
Jan Hegermann ◽  
Erika von Gromoff ◽  
Stefan Eimer ◽  
Ralf Baumeister ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Stress Response ◽  
Parkinson Disease ◽  
Neurite Outgrowth ◽  
Physiological Role ◽  
Model Organisms ◽  
Loss Of Function ◽  
C Elegans ◽  
Genes Encoding

Mutations in two genes encoding the putative kinases LRRK2 and PINK1 have been associated with inherited variants of Parkinson disease. The physiological role of both proteins is not known at present, but studies in model organisms have linked their mutants to distinct aspects of mitochondrial dysfunction, increased vulnerability to oxidative and endoplasmic reticulum stress, and intracellular protein sorting. Here, we show that a mutation in the Caenorhabditits elegans homologue of the PTEN-induced kinase pink-1 gene resulted in reduced mitochondrial cristae length and increased paraquat sensitivity of the nematode. Moreover, the mutants also displayed defects in axonal outgrowth of a pair of canal-associated neurons. We demonstrate that in the absence of lrk-1, the C. elegans homologue of human LRRK2, all phenotypic aspects of pink-1 loss-of-function mutants were suppressed. Conversely, the hypersensitivity of lrk-1 mutant animals to the endoplasmic reticulum stressor tunicamycin was reduced in a pink-1 mutant background. These results provide the first evidence of an antagonistic role of PINK-1 and LRK-1. Due to the similarity of the C. elegans proteins to human LRRK2 and PINK1, we suggest a common role of both factors in cellular functions including stress response and regulation of neurite outgrowth. This study might help to link pink-1/PINK1 and lrk-1/LRRK2 function to the pathological processes resulting from Parkinson disease-related mutants in both genes, the first manifestations of which are cytoskeletal defects in affected neurons.

Essential Role of the INK4/CDK4,6/Rb/E2F Signaling Pathway in AML with the Flt3 Internal Tandem Duplication.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 2752-2752
Author(s):  
Lisheng Wang ◽  
Jie Wang ◽  
Blaser W. Bradley ◽  
Caligiuri A. Michael ◽  
Briesewitz Roger
Keyword(s):  
Cell Lines ◽  
Essential Role ◽  
Tandem Duplication ◽  
Dependent Manner ◽  
U937 Cells ◽  
Phase I Clinical Trials ◽  
Internal Tandem Duplication ◽  
Survival Signal ◽  
Apoptotic Protein

Abstract Mutationally activated tyrosine kinases provide a critical survival signal to cancer cells, thus, making such kinases and their downstream effectors attractive targets for cancer therapy. To study signaling of mutated kinases we have chosen the receptor tyrosine kinase Flt3 that harbors an activating internal tandem duplication (ITD) in about 25% of AML patients. The use of a Flt3 inhibitor (THRX-165724, Theravance, Inc.) in two Flt3 ITD AML cell lines (MOLM13 and MV4-11) led to the inhibition of the INK4/CDK4,6/Rb/E2F pathway within three hours as reflected by the downregulation of D-cyclin gene expression followed by a decrease in D-cyclin protein. As a result of reduced D-cyclin levels, CDK4,6 activity was downregulated as revealed by the hypophosphorylation of the main substrate of CDK4,6, the Rb protein. THRX-165724 had no effect on D-cyclin levels or Rb hyperphosphorylation in THP-1 and U937 cells, two AML cell lines that express wildtype Flt3. Furthermore, THRX-165724 did not affect the proliferation or survival of these two cell lines. To investigate the role of the INK4/CDK4,6/Rb/E2F pathway as part of the proliferation and survival signal provided by the Flt3 ITD, we used PD-0332991, a highly selective CDK4,6 kinase inhibitor from Pfizer currently in phase I clinical trials for solid tumors. A dose-response experiment revealed that in cells PD-0332991 inhibits CDK4,6 activity with an IC50 of 30–40 nM as assayed by following the dephosphorylation of Rb. The compound does not inhibit Flt3 kinase activity even at the highest concentrations tested (500 nM). In MV4-11 and MOLM13 cells, PD-0332991 induced G1 specific cell cycle arrest within 24 hours and apoptosis after 3 days. Hence, in MV4-11 and MOLM13, PD-0332991 is cytostatic and cytotoxic. In contrast, PD-0332991 was neither cytotoxic nor cytostatic in THP-1 and U937 cells. In a clonogenic assay PD-0332991 reduced in a dose dependent manner the colony formation of MV4-11 and MOLM13 cells as well as primary patient blasts with Flt3 ITD. In contrast, THP-1 and U937 cells as well as CD34+ primary hematopoietic progenitor cells were not affected in their ability to form colonies. In MV4-11 and MOLM13 cells PD-0332991 induced the downregulation of the anti-apoptotic protein Bcl-2 and in MOLM13 it also induced the upregulation of the pro-apoptotic protein Bak. The deregulation of Bcl-2 and Bak may represent the underlying mechanism for the observed cytotoxicity of PD-0332991 in MV4-11 and MOLM13. In a mouse model of AML, NOD/SCID mice were inoculated with MOLM13 cells which caused leukemia within eight days. Mice treated with PD-0332991 starting at day seven after inoculation had a significant survival advantage demonstrating that PD-0332991 has anti-leukemic activity in vivo (median survival time 15.0 days versus 11.5 days, P=.0003). Our data suggest that the activation of the INK4/CDK4,6/Rb/E2F pathway by Flt3 ITD has an essential role for proliferation and survival in AML cells. Targeting the INK4/CDK4,6/Rb/E2F pathway in Flt3 ITD AML using CDK4,6 inhibitors like PD-0332991 should be explored for clinical efficacy in FLT3 ITD AML.

Targeting Proteinkinase C Alters ER-Stress and b-Catenin Signaling in Multiple Myeloma: Therapeutic Implications.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 258-258
Author(s):  
Marc S. Raab ◽  
Klaus Podar ◽  
Jing Zhang ◽  
Giovanni Tonon ◽  
Johannes H. Fruehauf ◽  
...  
Keyword(s):  
Cell Death ◽  
Stress Response ◽  
Growth Inhibition ◽  
Er Stress ◽  
Cell Lines ◽  
Wnt Pathway ◽  
Dependent Manner ◽  
P53 Family ◽  
Er Stress Response

Abstract We have previously shown that the novel orally available small molecule inhibitor of PKC enzastaurin (Eli Lilly and Company) inhibits MM cell growth, survival and angiogenesis both in vitro and in vivo. To date, however, the downstream effects contributing to growth inhibition and cell death remain to be determined. Here, we performed global gene expression profiling on enzastaurin treated MM cells and identified 200 Genes to be differentially regulated with a > 2-fold cut off. Strikingly, two major groups of up-regulated probe sets were associated with either of two pathways - endoplasmatic reticulum (ER)-stress response or WNT-signaling. Importantly, MM cells, producing high levels of paraprotein, are highly susceptible to perturbation of ER function and protein folding. Moreover, PKC isoforms have been reported to directly regulate the canonical WNT pathway via phosphorylation of b-catenin (CAT), leading to its ubiquination and proteasomal degradation. Specifically, we fist evaluated the role of enzastaurin in mediating ER-stress in MM cells. The transcriptional up-regulation of genes involved in ER-stress (GADD153/CHOP, GADD34, ATF3), triggered by enzastaurin at 3h, was confirmed by western blot analysis, accompanied by induction of the molecular ER chaperone BiP/grp78, phosphorylation of eIF2a consistent with PERK activation, and up-regulation of p21. These events were preceded by an early (1h) increase of intracellular calcium levels, a hallmark of ER-stress, assessed by FLUO4 staining. These data suggest an important role of ER-stress response in the early growth inhibition of MM cells caused by enzastaurin. Second, we delineated effects of enzastaurin on WNT pathway in MM and other tumor cell lines. Upon enzastaurin treatment, CAT was dephosphorylated at Ser33, 37, 41 in a dose- and time-dependent manner in all cell lines tested (10 MM, 3 colon cancer, HeLa, as well as human embryonic kidney 293 cells). Consequently, accumulation of CAT occurred in both cytosolic and nuclear fractions of treated MM cells, associated with activated TOPflash LUC-reporter system, confirming nuclear transactivating activity. Specific inhibition of CAT by siRNA partially rescued HeLa, HEK 293, and MM cells from cell death induced by enzastaurin. Analysis of downstream target molecules revealed a CAT-dependent up-regulation of c-Jun, but not of c-Myc or Cyclin D1. c-Jun has been reported to stabilize p73, a pro-apoptotic p53-family member; CAT induction by enzastaurin led to p73 (but not p53) activation and was also abrogated by CAT-specific siRNA. In turn, specific knockdown of p73 by siRNA rescued cells from enzastaurin-induced apoptosis. Finally, ectopic overexpression of CAT in HeLa and MM cells induced c-Jun expression and p73 activation, followed by apoptotic cell death. Our studies therefore indicate that ER-stress response contributes to the immediate inhibition of proliferation by enzastaurin, followed by CAT accumulation leading to p73 activation, contributing to enzastaurin-mediated cell death. These findings provide a novel link between CAT and p53-family members. Moreover p73, which is only rarely mutated in human cancers, represents a novel therapeutic target in MM.

scholarly journals Axin-mediated regulation of lifespan and muscle health in C. elegans involves AMPK-FOXO signaling

2020 ◽  
Author(s):  
Avijit Mallick ◽  
Ayush Ranawade ◽  
Bhagwati P Gupta
Keyword(s):  
Muscle Function ◽  
Significant Risk ◽  
Significant Risk Factor ◽  
Mitochondrial Morphology ◽  
Dependent Manner ◽  
C Elegans ◽  
Muscle Aging ◽  
Muscle Health ◽  
Multiple Signaling

SUMMARYAging is a significant risk factor for several diseases. Studies have uncovered multiple signaling pathways that modulate the process of aging including the Insulin/IGF-1 signaling (IIS). In C. elegans the key regulator of IIS is DAF-16/FOXO whose activity is regulated by phosphorylation. A major kinase involved in DAF-16-mediated lifespan extension is the AMPK catalytic subunit homolog, AAK-2. In this study, we demonstrate a novel role of PRY-1/Axin in AAK-2 activation to regulate DAF-16 function. The pry-1 transcriptome contains many genes associated with aging and muscle function. Consistent with this, pry-1 is strongly expressed in muscles and muscle-specific overexpression of pry-1 extends the lifespan, delays muscle aging, and improves mitochondrial morphology in DAF-16-dependent manner. Furthermore, PRY-1 is necessary for AAK-2 phosphorylation. Together, our data demonstrate a crucial role of PRY-1 in maintaining the lifespan and muscle health. Since muscle health declines with age, our study offers new possibilities to manipulate Axin function to delay muscle aging and improve lifespan.

scholarly journals Conserved Roles of C. elegans and Human MANFs in Sulfatide Binding and Cytoprotection

2018 ◽  
Author(s):  
Meirong Bai ◽  
Roman Vozdek ◽  
Aleš Hnízda ◽  
Chenxiao Jiang ◽  
Bingying Wang ◽  
...  
Keyword(s):  
Stress Response ◽  
Er Stress ◽  
Stress Responses ◽  
Mammalian Cells ◽  
Dopamine Neurons ◽  
Lipid Mediator ◽  
Outer Cell ◽  
Dependent Manner ◽  
C Elegans ◽  
Er Stress Response

AbstractMesencephalic Astrocyte-Derived Neurotrophic Factor (MANF) is an endoplasmic reticulum (ER) protein that can be secreted and protect dopamine neurons and cardiomyocytes from ER stress and apoptosis. The mechanism of action of extracellular MANF has long been elusive. From a genetic screen for mutants with abnormal ER stress response, we identified the gene Y54G2A.23 as the evolutionarily conserved C. elegans MANF orthologue. We find that MANF binds to the lipid sulfatide, also known as 3-O-sulfogalactosylceramide present in serum and outer-cell membrane leaflets, directly in isolated forms and in reconstituted lipid micelles. Sulfatide binding promotes cellular MANF uptake and cytoprotection from hypoxia-induced cell death. Heightened ER stress responses of MANF-null C. elegans mutants and mammalian cells are alleviated by human MANF in a sulfatide-dependent manner. Our results demonstrate conserved roles of MANF in sulfatide binding and ER stress response, supporting sulfatide as a long-sought lipid mediator of MANF’s cytoprotection.

scholarly journals Neuroendocrine Modulation Sustains the C. elegans Forward Motor State

2016 ◽  
Author(s):  
Maria A. Lim ◽  
Jyothsna Chitturi ◽  
Valeriya Laskova ◽  
Jun Meng ◽  
Daniel Findeis ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Calcium Imaging ◽  
Neural Circuit ◽  
Transcriptome Profiling ◽  
Behavioral State ◽  
Forward Movement ◽  
C Elegans ◽  
Peptidergic Neuron ◽  
Homeobox Transcription Factor

AbstractNeuromodulators shape neural circuit dynamics. Combining electron microscopy, genetics, transcriptome profiling, calcium imaging, and optogenetics, we discovered a peptidergic neuron that modulates C. elegans motor circuit dynamics. The Six/SO-family homeobox transcription factor UNC-39 governs lineage-specific neurogenesis to give rise to a neuron RID. RID bears the anatomic hallmarks of a specialized endocrine neuron: it harbors near-exclusive dense core vesicles that cluster periodically along the axon, and expresses multiple neuropeptides, including the FMRF-amide-related FLP-14. RID activity increases during forward movement. Ablating RID reduces the sustainability of forward movement, a phenotype partially recapitulated by removing FLP-14. Optogenetic depolarization of RID prolongs forward movement, an effect reduced in the absence of FLP-14. Together, these results establish the role of a neuroendocrine cell RID in sustaining a specific behavioral state in C. elegans.

scholarly journals Targeted knock-in mice with a human mutation in GRTH/DDX25 reveals the essential role of phosphorylated GRTH in spermatid development during spermatogenesis

2019 ◽  
Vol 28 (15) ◽  
pp. 2561-2572 ◽  
Author(s):  
Raghuveer Kavarthapu ◽  
Rajakumar Anbazhagan ◽  
Murugananthkumar Raju ◽  
Chon-Hwa Tsai Morris ◽  
James Pickel ◽  
...  
Keyword(s):  
Essential Role ◽  
Round Spermatid ◽  
Dependent Manner ◽  
Testis Size ◽  
Rna Helicases ◽  
Dead Box ◽  
Chromatoid Bodies ◽  
Human Mutation ◽  
Related Proteins

Abstract Gonadotropin-regulated testicular RNA helicase (GRTH/DDX25) is a testis specific member of the DEAD-box family of RNA helicases expressed in meiotic and haploid germ cells which plays an essential role in spermatogenesis. There are two species of GRTH the 56 kDa non-phospho and 61 kDa phospho forms. Our early studies revealed a missense mutation (R242H) of GRTH in azoospermic men that when expressed in COS1-cells lack the phospho-form of GRTH. To investigate the role of the phospho-GRTH species in spermatogenesis, we generated a GRTH knock-in (KI) transgenic mice with the R242H mutation. GRTH-KI mice are sterile with reduced testis size, lack sperm with spermatogenic arrest at round spermatid stage and loss of the cytoplasmic phospho-GRTH species. Electron microscopy studies revealed reduction in the size of chromatoid bodies (CB) of round spermatids (RS) and germ cell apoptosis. We observed absence of phospho-GRTH in the CB of RS. Complete loss of chromatin remodeling and related proteins such as TP2, PRM2, TSSK6 and marked reduction of their respective mRNAs and half-lives were observed in GRTH-KI mice. We showed that phospho-GRTH has a role in TP2 translation and revealed its occurrence in a 3′ UTR dependent manner. These findings demonstrate the relevance of phospho-GRTH in the structure of the chromatoid body, spermatid development and completion of spermatogenesis and provide an avenue for the development of a male contraceptive.

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