title: PGL proteins self associate and bind RNPs to mediate germ granule assembly in C. elegans.
abstract: Germ granules are germ lineage-specific ribonucleoprotein (RNP) complexes, but how they are assembled and specifically segregated to germ lineage cells remains unclear. Here, we show that the PGL proteins PGL-1 and PGL-3 serve as the scaffold for germ granule formation in Caenorhabditis elegans. Using cultured mammalian cells, we found that PGL proteins have the ability to self-associate and recruit RNPs. Depletion of PGL proteins from early C. elegans embryos caused dispersal of other germ granule components in the cytoplasm, suggesting that PGL proteins are essential for the architecture of germ granules. Using a structure-function analysis in vivo, we found that two functional domains of PGL proteins contribute to germ granule assembly: an RGG box for recruiting RNA and RNA-binding proteins and a self-association domain for formation of globular granules. We propose that self-association of scaffold proteins that can bind to RNPs is a general mechanism by which large RNP granules are formed.
authors.affiliation: Laboratory for Developmental Genomics, RIKEN Center for Developmental Biology, Kobe, Hyogo, 650-0047 Japan.
authors.forename: Momoyo
authors.initials: M
authors.lastname: Hanazawa
authors.forename: Masafumi
authors.initials: M
authors.lastname: Yonetani
authors.forename: Asako
authors.initials: A
authors.lastname: Sugimoto
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D016466:CHO Cells; D017173:Caenorhabditis elegans / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D019070:Cell Lineage; D006224:Cricetinae; D003412:Cricetulus; D003594:Cytoplasmic Granules / Q000378:metabolism*; D005854:Germ Cells / Q000166:cytology / Q000378:metabolism*; D034622:RNA Interference; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012261:Ribonucleoproteins / Q000378:metabolism*
chemical_list: D029742:Caenorhabditis elegans Proteins; C114543:PGL-1 protein, C elegans; C534959:PGL-3 protein, C elegans; D016601:RNA-Binding Proteins; D011993:Recombinant Fusion Proteins; D012261:Ribonucleoproteins