title: Processing bodies and germ granules are distinct RNA granules that interact in C. elegans embryos.
abstract: In somatic cells, untranslated mRNAs accumulate in cytoplasmic foci called processing bodies or P-bodies. P-bodies contain complexes that inhibit translation and stimulate mRNA deadenylation, decapping, and decay. Recently, certain P-body proteins have been found in germ granules, RNA granules specific to germ cells. We have investigated a possible connection between P-bodies and germ granules in Caenorhabditis elegans. We identify PATR-1, the C. elegans homolog of the yeast decapping activator Pat1p, as a unique marker for P-bodies in C. elegans embryos. We find that P-bodies are inherited maternally as core granules that mature differently in somatic and germline blastomeres. In somatic blastomeres, P-bodies recruit the decapping activators LSM-1 and LSM-3. This recruitment requires the LET-711/Not1 subunit of the CCR4-NOT deadenylase and correlates spatially and temporally with the onset of maternal mRNA degradation. In germline blastomeres, P-bodies are maintained as core granules lacking LSM-1 and LSM-3. P-bodies interact with germ granules, but maintain distinct dynamics and components. The maternal mRNA nos-2 is maintained in germ granules, but not in P-bodies. We conclude that P-bodies are distinct from germ granules, and represent a second class of RNA granules that behaves differently in somatic and germline cells.
authors.affiliation: Department of Molecular Biology and Genetics, Center for Cell Dynamics, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, 725 N Wolfe Street, 706 PCTB, Baltimore, MD 21205, USA.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Gallo
authors.forename: Edwin
authors.initials: E
authors.lastname: Munro
authors.forename: Dominique
authors.initials: D
authors.lastname: Rasoloson
authors.forename: Christopher
authors.initials: C
authors.lastname: Merritt
authors.forename: Geraldine
authors.initials: G
authors.lastname: Seydoux
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000166:cytology / Q000196:embryology / Q000235:genetics / Q000378:metabolism*; D003594:Cytoplasmic Granules / Q000235:genetics / Q000378:metabolism*; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000378:metabolism; D019084:Fluorescent Antibody Technique, Indirect; D005854:Germ Cells / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D017403:In Situ Hybridization; D017404:In Situ Hybridization, Fluorescence; D002479:Inclusion Bodies / Q000378:metabolism*; D008954:Models, Biological; D012313:RNA / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference; D012323:RNA Processing, Post-Transcriptional; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D019076:Transgenes
chemical_list: D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D012313:RNA