title: Loss of PGL-1 and PGL-3, members of a family of constitutive germ-granule components, promotes germline apoptosis in C. elegans.
abstract: In Caenorhabditis elegans, the mechanisms regulating germline apoptosis remain largely unknown, except for the core machinery. Here, we found that mutants of pgl-1 and pgl-3, encoding members of a family of constitutive protein components of germline-specific P granules, showed increased germline apoptosis under both physiological and DNA-damaged conditions. We also found that the number of germ cells that lost PGL proteins increased significantly following UV irradiation, and that only those PGL-absent germ cells were selectively engulfed by gonadal sheath cells in adult hermaphrodite gonads. We further revealed that CEP-1, the p53 homolog, and the caspase CED-3 promoted elimination of PGL-1 from germ cells following UV irradiation. Furthermore, protein levels of CED-4, the Apaf-1 homolog, and cytoplasmic translocation of SIR-2.1, a Sirtuin homolog, significantly increased in pgl mutants and increased even more following UV irradiation. CED-4 and SIR-2.1 were essential for high levels of germline apoptosis in pgl mutants. We conclude that PGL proteins suppress excessive germline apoptosis by repressing both the protein levels of CED-4 and the cytoplasmic translocation of SIR-2.1. Our study has revealed new roles for PGL-1 and PGL-3 in the control of germline apoptosis.
authors.affiliation: Department of Bioscience and Biotechnology, Konkuk University, Seoul 143-701, Republic of Korea.
authors.forename: Hyemin
authors.initials: H
authors.lastname: Min
authors.affiliation: Department of Bioscience and Biotechnology, Konkuk University, Seoul 143-701, Republic of Korea Institute of KU Biotechnology, Konkuk University, Seoul 143-701, Republic of Korea yshim@konkuk.ac.kr ikawasak@mac.com.
authors.forename: Yhong-Hee
authors.initials: YH
authors.lastname: Shim
authors.affiliation: Department of Bioscience and Biotechnology, Konkuk University, Seoul 143-701, Republic of Korea Institute of KU Biotechnology, Konkuk University, Seoul 143-701, Republic of Korea yshim@konkuk.ac.kr ikawasak@mac.com.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Kawasaki
mesh_terms: D000818:Animals; D017209:Apoptosis; D017173:Caenorhabditis elegans / Q000166:cytology / Q000235:genetics; D029742:Caenorhabditis elegans Proteins / Q000235:genetics* / Q000378:metabolism; D020169:Caspases / Q000378:metabolism; D004843:Epistasis, Genetic; D057850:Hermaphroditic Organisms / Q000166:cytology / Q000235:genetics; D008297:Male; D021381:Protein Transport; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D013094:Spermatozoa / Q000166:cytology; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
chemical_list: C438244:CEP-1 protein, C elegans; D029742:Caenorhabditis elegans Proteins; C114543:PGL-1 protein, C elegans; C534959:PGL-3 protein, C elegans; D016601:RNA-Binding Proteins; D016159:Tumor Suppressor Protein p53; D020169:Caspases; C089223:ced-3 protein, C elegans
keywords: Caenorhabditis elegans; Germline apoptosis; P granules; PGL-1; PGL-3