A regulatory cytoplasmic poly(A) polymerase in Caenorhabditis elegans.
Messenger RNA regulation is a critical mode of controlling gene expression. Regulation of mRNA stability and translation is linked to controls of poly(A) tail length. Poly(A) lengthening can stabilize and translationally activate mRNAs, whereas poly(A) removal can trigger degradation and translational repression. Germline granules (for example, polar granules in flies, P granules in worms) are ribonucleoprotein particles implicated in translational control. Here we report that the Caenorhabditis elegans gene gld-2, a regulator of mitosis/meiosis decision and other germline events, encodes the catalytic moiety of a cytoplasmic poly(A) polymerase (PAP) that is associated with P granules in early embryos. Importantly, the GLD-2 protein sequence has diverged substantially from that of conventional eukaryotic PAPs, and lacks a recognizable RRM (RNA recognition motif)-like domain. GLD-2 has little PAP activity on its own, but is stimulated in vitro by GLD-3. GLD-3 is also a developmental regulator, and belongs to the Bicaudal-C family of RNA binding proteins. We suggest that GLD-2 is the prototype for a class of regulatory cytoplasmic PAPs that are recruited to specific mRNAs by a binding partner, thereby targeting those mRNAs for polyadenylation and increased expression.
Wang
Liaoteng
L
Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
Eckmann
Christian R
CR
Kadyk
Lisa C
LC
Wickens
Marvin
M
Kimble
Judith
J
D000595:Amino Acid Sequence; D000818:Animals; D017173:Caenorhabditis elegans / Q000196:embryology / Q000201:enzymology* / Q000235:genetics; D029742:Caenorhabditis elegans Proteins / Q000737:chemistry / Q000235:genetics* / Q000276:immunology / Q000378:metabolism*; D020134:Catalytic Domain; D003001:Cloning, Molecular; D003593:Cytoplasm / Q000201:enzymology*; D019281:Dimerization; D004625:Embryo, Nonmammalian / Q000201:enzymology; D019143:Evolution, Molecular; D018095:Germ-Line Mutation / Q000235:genetics; D008954:Models, Biological; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011061:Poly A / Q000378:metabolism; D026723:Polyadenylation; D011062:Polynucleotide Adenylyltransferase / Q000737:chemistry / Q000235:genetics* / Q000276:immunology / Q000378:metabolism*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D018510:RNA, Helminth / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000378:metabolism
D029742:Caenorhabditis elegans Proteins; D018510:RNA, Helminth; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D011061:Poly A; D011062:Polynucleotide Adenylyltransferase