Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P10415 (Bcl-2)
 33,771 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Programmed cell death (apoptosis) is essential for the development and homeostasis of metazoans. The central step in the execution of programmed cell death is the activation of caspases. In C. elegans, the core cell death regulators EGL-1(a BH3 domain-containing protein), CED-9 (Bcl-2), and CED-4 (Apaf-1) act in an inhibitory cascade to activate the CED-3 caspase. Here we have identified an additional component eif-3.K (eukaryotic translation initiation factor 3 subunit k) that acts upstream of ced-3 to promote programmed cell death. The loss of eif-3.K reduced cell deaths in both somatic and germ cells, whereas the overexpression of eif-3.K resulted in a slight but significant increase in cell death. Using a cell-specific promoter, we show that eif-3.K promotes cell death in a cell-autonomous manner. In addition, the loss of eif-3.K significantly suppressed cell death-induced through the overexpression of ced-4, but not ced-3, indicating a distinct requirement for eif-3.K in apoptosis. Reciprocally, a loss of ced-3 suppressed cell death induced by the overexpression of eif-3.K. These results indicate that eif-3.K requires ced-3 to promote programmed cell death and that eif-3.K acts upstream of ced-3 to promote this process. The EIF-3.K protein is ubiquitously expressed in embryos and larvae and localizes to the cytoplasm. A structure-function analysis revealed that the 61 amino acid long WH domain of EIF-3.K, potentially involved in protein-DNA/RNA interactions, is both necessary and sufficient for the cell death-promoting activity of EIF-3.K. Because human eIF3k was able to partially substitute for C. elegans eif-3.K in the promotion of cell death, this WH domain-dependent EIF-3.K-mediated cell death process has potentially been conserved throughout evolution.
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PMID:C. elegans EIF-3.K promotes programmed cell death through CED-3 caspase. 2259 May 72

In the past 12 years, since the first description of C. elegans germ cell apoptosis, this area of research rapidly expanded. It became evident that multiple genetic pathways lead to the apoptotic demise of germ cells. We are only beginning to understand how these pathways that all require the CED-9/Bcl-2, Apaf-1/CED-4 and CED-3 caspase core apoptosis components are regulated. Physiological apoptosis, which likely accounts for the elimination of more than 50% of all germ cells, even in unperturbed conditions, is likely to be required to maintain tissue homeostasis. The best-studied pathways lead to DNA damage-induced germ cell apoptosis in response to a variety of genotoxic stimuli. This apoptosis appears to be regulated similar to DNA damage-induced apoptosis in the mouse germ line and converges on p53 family transcription factors. DNA damage response pathways not only lead to apoptosis induction, but also directly affect DNA repair, and a transient cell cycle arrest of mitotic germ cells. Finally, distinct pathways activate germ cell apoptosis in response to defects in meiotic recombination and meiotic chromosome pairing.
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PMID:Germ cell apoptosis and DNA damage responses. 2287 80

Proteins belonging to Bcl-2 family regulate intrinsic cell death pathway. Although mammalian antiapoptotic Bcl-2 members interact with multiple proapoptotic proteins, the Caenorhabditis elegans Bcl-2 homolog CED-9 is known to have only two proapoptotic partners. The BH3-motif of proapoptotic proteins bind to the hydrophobic groove of prosurvival proteins formed by the Bcl-2 helical fold. CED-9 is also known to interact with CED-4, a homolog of the human cell death activator Apaf1. We have performed molecular dynamics simulations of CED-9 in two forms and compared the results with those of mammalian counterparts Bcl-XL, Bcl-w, and Bcl-2. Our studies demonstrate that the region forming the hydrophobic cleft is more flexible compared with the CED-4-binding region, and this is generally true for all antiapoptotic Bcl-2 proteins studied. CED-9 is the most stable protein during simulations and its hydrophobic pocket is relatively rigid explaining the absence of functional redundancy in CED-9. The BH3-binding region of Bcl-2 is less flexible among the mammalian proteins and this lends support to the studies that Bcl-2 binds to less number of BH3 peptides with high affinity. The C-terminal helix of CED-9 lost its helical character because of a large number of charged residues. We speculate that this region probably plays a role in intracellular localization of CED-9. The BH4-motif accessibility in CED-9 and Bcl-w is controlled by the loop connecting the first two helices. Although CED-9 adopts the same Bcl-2 fold, our studies highlight important differences in the dynamic behavior of CED-9 and mammalian antiapoptotic homologs.
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PMID:Antiapoptotic Bcl-2 homolog CED-9 in Caenorhabditis elegans: dynamics of BH3 and CED-4 binding regions and comparison with mammalian antiapoptotic Bcl-2 proteins. 2421 65

The induction of apoptosis is recognized to be a major mechanism of tributyltin (TBT) toxicity. However, the underlying signaling pathways for TBT-induced apoptosis remain unclear. In this study, using the nematode Caenorhabditis elegans, we examined whether DNA damage response (DDR) pathway and mitogen-activated protein kinase (MAPK) signaling cascades are involved in TBT-induced germline apoptosis and cell cycle arrest. Our results demonstrated that exposing worms to TBT at the dose of 10nM for 6h significantly increased germline apoptosis in N2 strain. Germline apoptosis was absent in strains that carried ced-3 or ced-4 loss-of-function alleles, indicating that both caspase protein CED-3 and Apaf-1 protein CED-4 were required for TBT-induced apoptosis. TBT-induced apoptosis was blocked in the Bcl-2 gain-of-function strain ced-9(n1950), whereas TBT induced a minor increase in the BH3-only protein EGL-1 mutated strain egl-1(n1084n3082). Checkpoint proteins HUS-1 and CLK-2 exerted proapoptotic effects, and the null mutation of cep-1, the homologue of tumor suppressor gene p53, significantly inhibited TBT-induced apoptosis. Apoptosis in the loss-of-function strains of ERK, JNK and p38 MAPK signaling pathways were completely or mildly suppressed under TBT stress. These results were supported by the results of mRNA expression levels of corresponding genes. The present study indicated that TBT-induced apoptosis required the core apoptotic machinery, and that DDR genes and MAPK pathways played essential roles in signaling the processes.
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PMID:The roles of DNA damage-dependent signals and MAPK cascades in tributyltin-induced germline apoptosis in Caenorhabditis elegans. 2453 58

Programmed cell death, which occurs through a conserved core molecular pathway, is important for fundamental developmental and homeostatic processes. The human iron-sulfur binding protein NAF-1/CISD2 binds to Bcl-2 and its disruption in cells leads to an increase in apoptosis. Other members of the CDGSH iron sulfur domain (CISD) family include mitoNEET/CISD1 and Miner2/CISD3. In humans, mutations in CISD2 result in Wolfram syndrome 2, a disease in which the patients display juvenile diabetes, neuropsychiatric disorders and defective platelet aggregation. The C. elegans genome contains three previously uncharacterized cisd genes that code for CISD-1, which has homology to mitoNEET/CISD1 and NAF-1/CISD2, and CISD-3.1 and CISD-3.2, both of which have homology to Miner2/CISD3. Disrupting the function of the cisd genes resulted in various germline abnormalities including distal tip cell migration defects and a significant increase in the number of cell corpses within the adult germline. This increased germ cell death is blocked by a gain-of-function mutation of the Bcl-2 homolog CED-9 and requires functional caspase CED-3 and the APAF-1 homolog CED-4. Furthermore, the increased germ cell death is facilitated by the pro-apoptotic, CED-9-binding protein CED-13, but not the related EGL-1 protein. This work is significant because it places the CISD family members as regulators of physiological germline programmed cell death acting through CED-13 and the core apoptotic machinery.
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PMID:The cisd gene family regulates physiological germline apoptosis through ced-13 and the canonical cell death pathway in Caenorhabditis elegans. 2966 74


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