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Biomedical subjects

W N Chen

Publications and source records attributed to W N Chen.

32 records · Page 2Linked to original sources

Cloning and functional analysis of the arginyl-tRNA-protein transferase gene ATE1 of Saccharomyces cerevisiae.

Aminoacyl-tRNA-protein transferases (Arg-transferases) catalyze post-translational conjugation of specific amino acids to the amino termini of acceptor proteins. A function of these enzymes in eukaryotes has been shown to involve the conjugation of destabilizing amino acids to the amino termini of short-lived proteins, these reactions being a part of the N-end rule pathway of protein degradation (Gonda, D. K., Bachmair, A., Wünning, I., Tobias, J. W., Lane, W. S., and Varshavsky, A. (1989) J. Biol. Chem. 264, 16700-16712). We have cloned the ATE1 gene of the yeast Saccharomyces cerevisiae which encodes arginyl-tRNA-protein transferase. ATE1 gives rise to a approximately 1.6-kilobase mRNA and codes for a 503-residue protein. Expression of the yeast ATE1 gene in Escherichia coli, which lacks Arg-transferases, was used to show that the ATE1 protein possesses the Arg-transferase activity. Null ate1 mutants are viable but lack the Arg-transferase activity and are unable to degrade those substrates of the N-end rule pathway that start with residues recognized by the Arg-transferase.

Acyltransferases↗

The suppressor gene scl1+ of Saccharomyces cerevisiae is essential for growth.

In Saccharomyces cerevisiae, the SCL-1 mutation is a dominant suppressor of the cycloheximide-resistant, temperature-sensitive (ts) lethal mutation, crl3 [McCusker and Haber, Genetics 119 (1988a) 303-315]. The wild-type scl1+ gene was isolated by screening subclones of the 35-kb region between TRP5 and LEU1 for restoration of the ts phenotype in an SCL1-1 crl3-2 strain. The scl1+ mRNA is about 900 nt long and encodes an open reading frame of 810 bp. The polypeptide deduced from scl1+ possesses a putative secretory signal peptide. The 5'-noncoding region may be under multiple controls, since it contains significant homology to the consensus sequences for the DNA-binding proteins, GCN4, GFI and, possibly, TUF. Gene disruption of scl1+ demonstrates that it is an essential gene.

Amino Acid Sequence↗