GLD-2/RNP-8 cytoplasmic poly(A) polymerase is a broad-spectrum regulator of the oogenesis program.
Regulated polyadenylation is a broadly conserved mechanism that controls key events during oogenesis. Pivotal to that mechanism is GLD-2, a catalytic subunit of cytoplasmic poly(A) polymerase (PAP). Caenorhabditis elegans GLD-2 forms an active PAP with multiple RNA-binding partners to regulate diverse aspects of germline and early embryonic development. One GLD-2 partner, RNP-8, was previously shown to influence oocyte fate specification. Here we use a genomic approach to identify transcripts selectively associated with both GLD-2 and RNP-8. Among the 335 GLD-2/RNP-8 potential targets, most were annotated as germline mRNAs and many as maternal mRNAs. These targets include gld-2 and rnp-8 themselves, suggesting autoregulation. Removal of either GLD-2 or RNP-8 resulted in shortened poly(A) tails and lowered abundance of four target mRNAs (oma-2, egg-1, pup-2, and tra-2); GLD-2 depletion also lowered the abundance of most GLD-2/RNP-8 putative target mRNAs when assayed on microarrays. Therefore, GLD-2/RNP-8 appears to polyadenylate and stabilize its target mRNAs. We also provide evidence that rnp-8 influences oocyte development; rnp-8 null mutants have more germ cell corpses and fewer oocytes than normal. Furthermore, RNP-8 appears to work synergistically with another GLD-2-binding partner, GLD-3, to ensure normal oogenesis. We propose that the GLD-2/RNP-8 enzyme is a broad-spectrum regulator of the oogenesis program that acts within an RNA regulatory network to specify and produce fully functional oocytes.
Kim
Kyung Won
KW
Department of Biochemistry and Howard Hughes Medical Institute, University of Wisconsin, Madison, WI 53706, USA.
Wilson
Tracy L
TL
Kimble
Judith
J
D000818:Animals; D017173:Caenorhabditis elegans / Q000033:anatomy & histology / Q000502:physiology*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D005260:Female; D005854:Germ Cells / Q000378:metabolism; D046228:Microarray Analysis; D009865:Oocytes / Q000166:cytology / Q000502:physiology; D009866:Oogenesis / Q000502:physiology*; D011061:Poly A / Q000378:metabolism; D011062:Polynucleotide Adenylyltransferase / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
D029742:Caenorhabditis elegans Proteins; D002352:Carrier Proteins; D012333:RNA, Messenger; C541033:RNP-8 protein, C elegans; D011061:Poly A; C491056:GLD-2 protein, C elegans; D011062:Polynucleotide Adenylyltransferase