Abstract
A survey of RNases in Xenopus laevis oocytes has been carried out to identify potential tRNA-processing enzymes in this system. Using a variety of specific and nonspecific substrates, we have shown that oocytes contain multiple RNases with various specificities. Three activities that could cleave the extraneous residues from the artificial tRNA precursor, tRNA-C-[14C]U-C, to generate a substrate for -C-C-A addition by tRNA nucleotidyltransferase were identified. One of these was a cytoplasmic exonuclease which generated predominantly tRNA-C, whereas the other two were nuclear endonucleases which cleaved the precursor to generate tRNA-N. The possible involvement of these activities in 3' tRNA processing in oocytes is discussed.
Publisher
American Society for Microbiology
Subject
Cell Biology,Molecular Biology
Reference25 articles.
1. Relationship between the two components of the split promoter of eukaryotic tRNA genes;Ciliberto G.;Proc. Natl. Acad. Sci. U.S.A.,1982
2. Two control regions for eukaryotic tRNA gene transcription;DeFranco D.;Proc. Natl. Acad. Sci. U.S.A.,1980
3. Intranuclear location of the tRNA splicing enzymes;DeRobertis E. M.;Cell,1981
4. Purification and physical and chemical properties of rabbit liver tRNA nucleotidyltransferase;Deutscher M. P.;J. Biol. Chem.,1972
5. Anomalous AMP incorporation catalyzed by rabbit liver tRNA nucleotidyltransferase;Deutscher M. P.;J. Biol. Chem.,1973