Tissue-specific modification of gld-2 mRNA in C. elegans: likely C-to-U editing.
Seventeen years after the discovery of tissue-specific apoB mRNA editing, only three nucleus-encoded mRNAs have been shown to undergo C-to-U editing. All three mRNAs occur in mammals. apoB mRNA editing is tissue-specific and occurs normally, whereas NF1 and NAT1 mRNA editing is found largely in tumors. Here we report the first example of C-to-U RNA editing in Caenorhabditis elegans. The gld-2 gene encodes an atypical poly(A) polymerase that governs the mitosis/meiosis decision in the germ line as well as progression through meiosis and early embryogenesis. At least two of its alternatively spliced transcripts are germline-specific. We find that most and perhaps all germline-specific transcripts generated by the gld-2 gene undergo C-to-U editing, but that somatic transcripts show no detectable editing. The gld-2 C-to-U editing event changes the codon from CCG to CUG, which is predicted to cause a proline to leucine substitution in the protein sequence. Our findings suggest the presence of a sequence- and tissue-specific cytidine deaminase acting on RNA, or CDAR. This CDAR modifies a specific base in gld-2 mRNA, and acts only in the germline.
Wang
Liaoteng
L
Department of Biochemistry, 433 Babcock Drive, University of Wisconsin-Madison, 53706, USA.
Kimble
Judith
J
Wickens
Marvin
M
D000818:Animals; D001483:Base Sequence; D017173:Caenorhabditis elegans / Q000201:enzymology* / Q000235:genetics; D029742:Caenorhabditis elegans Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D003562:Cytidine / Q000737:chemistry / Q000235:genetics; D005854:Germ Cells; D008969:Molecular Sequence Data; D010802:Phylogeny; D011061:Poly A / Q000378:metabolism; D011062:Polynucleotide Adenylyltransferase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D011485:Protein Binding; D017393:RNA Editing / Q000235:genetics*; D018510:RNA, Helminth / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D012689:Sequence Homology, Nucleic Acid; D014529:Uridine / Q000737:chemistry / Q000235:genetics
D029742:Caenorhabditis elegans Proteins; D018510:RNA, Helminth; D012333:RNA, Messenger; D011061:Poly A; D003562:Cytidine; C491056:GLD-2 protein, C elegans; D011062:Polynucleotide Adenylyltransferase; D014529:Uridine