A Caltech Library Service

Alternative Splicing Results in Differential Expression, Activity, and Localization of the Two Forms of Arginyl-tRNA-Protein Transferase, a Component of the N-End Rule Pathway

Kwon, Yong Tae and Kashina, Anna S. and Varshavsky, Alexander (1999) Alternative Splicing Results in Differential Expression, Activity, and Localization of the Two Forms of Arginyl-tRNA-Protein Transferase, a Component of the N-End Rule Pathway. Molecular and Cellular Biology, 19 (1). pp. 182-193. ISSN 0270-7306. PMCID PMC83877.

PDF - Published Version
See Usage Policy.


Use this Persistent URL to link to this item:


The N-end rule relates the in vivo half-life of a protein to the identity of its N-terminal residue. The underlying ubiquitin-dependent proteolytic system, called the N-end rule pathway, is organized hierarchically: N-terminal aspartate and glutamate (and also cysteine in metazoans) are secondary destabilizing residues, in that they function through their conjugation, by arginyl-tRNA-protein transferase (R-transferase), to arginine, a primary destabilizing residue. We isolated cDNA encoding the 516-residue mouse R-transferase, ATE1p, and found two species, termed Ate1-1 and Ate1-2. The Ate1 mRNAs are produced through a most unusual alternative splicing that retains one or the other of the two homologous 129-bp exons, which are adjacent in the mouse Ate1 gene. Human ATE1 also contains the alternative 129-bp exons, whereas the plant (Arabidopsis thaliana) and fly (Drosophila melanogaster) Ate1 genes encode a single form of ATE1p. A fusion of ATE1-1p with green fluorescent protein (GFP) is present in both the nucleus and the cytosol, whereas ATE1-2p-GFP is exclusively cytosolic. Mouse ATE1-1p and ATE1-2p were examined by expressing them in ate1Delta Saccharomyces cerevisiae in the presence of test substrates that included Asp-beta gal (beta -galactosidase) and Cys-beta gal. Both forms of the mouse R-transferase conferred instability on Asp-beta gal (but not on Cys-beta gal) through the arginylation of its N-terminal Asp, the ATE1-1p enzyme being more active than ATE1-2p. The ratio of Ate1-1 to Ate1-2 mRNA varies greatly among the mouse tissues; it is ~0.1 in the skeletal muscle, ~0.25 in the spleen, ~3.3 in the liver and brain, and ~10 in the testis, suggesting that the two R-transferases are functionally distinct.

Item Type:Article
Related URLs:
URLURL TypeDescription CentralArticle
Varshavsky, Alexander0000-0002-4011-258X
Additional Information:© 1999, American Society for Microbiology. Received 13 August 1998/Returned for modification 21 September 1998/Accepted 6 October 1998 The first two authors contributed equally to this work. We thank Gary Hathaway of the Caltech Microchemistry Facility for the sequencing of X-beta gal proteins. We are grateful to Hai Rao, Glenn Turner, Fangyong Du, and Lawrence Peck for helpful suggestions and to Fangyong Du, Federico Navarro-Garcia, Hai Rao, and Youming Xie for comments on the manuscript. This work was supported by grants DK39520 and GM31530 to A.V. from the National Institutes of Health.
Funding AgencyGrant Number
PubMed Central ID:PMC83877
Record Number:CaltechAUTHORS:KWOmcb99
Persistent URL:
Alternative URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:6789
Deposited By: Archive Administrator
Deposited On:21 Dec 2006
Last Modified:17 Nov 2017 00:22

Repository Staff Only: item control page