The PGL family proteins associate with germ granules and function redundantly in Caenorhabditis elegans germline development.
PGL-1 is a constitutive protein component of C. elegans germ granules, also known as P granules. Maternally supplied PGL-1 is essential for germline development but only at elevated temperature, raising the possibility that redundant factors provide sufficient function at lower temperatures. We have identified two PGL-1-related proteins, PGL-2 and PGL-3, by sequence analysis of the C. elegans genome and by a yeast two-hybrid screen for proteins that interact with PGL-1. PGL-3 is associated with P granules at all stages of development, while PGL-2 is associated with P granules only during postembryonic development. All three PGL proteins interact with each other in vitro. Furthermore, PGL-1 and PGL-3 are co-immunoprecipitated from embryo extracts, indicating that they are indeed in the same protein complex in vivo. Nevertheless, each PGL protein localizes to P granules independently of the other two. pgl-2 or pgl-3 single-mutant worms do not show obvious defects in germline development. However, pgl-1; pgl-3 (but not pgl-2; pgl-1) double-mutant hermaphrodites and males show significantly enhanced sterility at all temperatures, compared to pgl-1 alone. Mutant hermaphrodites show defects in germline proliferation and in production of healthy gametes and viable embryos. Our findings demonstrate that both PGL-2 and PGL-3 are components of P granules, both interact with PGL-1, and at least PGL-3 functions redundantly with PGL-1 to ensure fertility in both sexes of C. elegans.
Kawasaki
Ichiro
I
PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012, Japan. ikawasak@gen.s.u-tokyo.ac.jp
Amiri
Anahita
A
Fan
Yuan
Y
Meyer
Nicole
N
Dunkelbarger
Steve
S
Motohashi
Tomoko
T
Karashima
Takeshi
T
Bossinger
Olaf
O
Strome
Susan
S
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017173:Caenorhabditis elegans / Q000235:genetics* / Q000254:growth & development; D029742:Caenorhabditis elegans Proteins / Q000737:chemistry / Q000235:genetics*; D003594:Cytoplasmic Granules / Q000235:genetics / Q000502:physiology; D017931:DNA Primers; D005260:Female; D005298:Fertility; D018095:Germ-Line Mutation; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism; D017403:In Situ Hybridization; D008297:Male; D008969:Molecular Sequence Data; D016296:Mutagenesis; D016133:Polymerase Chain Reaction; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000235:genetics*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D016415:Sequence Alignment; D017384:Sequence Deletion; D017386:Sequence Homology, Amino Acid
D029742:Caenorhabditis elegans Proteins; D017931:DNA Primers; C114543:PGL-1 protein, C elegans; D020033:Protein Isoforms; D016601:RNA-Binding Proteins; D011993:Recombinant Fusion Proteins; D005982:Glutathione Transferase