Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published March 15, 1992 | Published
Journal Article Open

A gene encoding a putative tyrosine phosphatase suppresses lethality of an N-end rule-dependent mutant


The N-end rule relates the in vivo half-life of a protein to the identity of its N-terminal residue. In the yeast Saccharomyces cerevisiae, mutational inactivation of the N-end rule pathway is neither lethal nor phenotypically conspicuous. We have used a "synthetic lethal" screen to isolate a mutant that requires the N-end rule pathway for viability. An extragenic suppressor of this mutation was cloned and found to encode a 750-residue protein with strong sequence similarities to protein phosphotyrosine phosphatases. This heat-inducible gene was named PTP2. Null ptp2 mutants grow slowly, are hypersensitive to heat, and are viable in either the presence or absence of the N-end rule pathway. We discuss possible connections between dephosphorylation of phosphotyrosine in proteins and the N-end rule pathway of protein degradation.

Additional Information

© 1992 by the National Academy of Sciences. Communicated by Alexander Rich, October 18, 1991. We are indebted to M. Bernstein and A. Browne for technical assistance and to R. Baker, B. Bartel, J. Dohmen, K. Madura, E. Johnson, and N. Johnsson for discussions, advice, and comments on the manuscript. We also thank R. Baker for the gift of a Northern blot and B. Doran for secretarial assistance. This work was supported by grants to A.V. from the National Institutes of Health (DK39520 and GM31530). I.M.O. was supported by a postdoctoral fellowship from the Damon Runyon-Walter Winchell Cancer Fund. The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. §1734 solely to indicate this fact.

Attached Files

Published - OTApnas92.pdf


Files (1.4 MB)
Name Size Download all
1.4 MB Preview Download

Additional details

August 22, 2023
October 13, 2023