Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

A novel protein modification pathway related to the ubiquitin system

A novel protein modification pathway related to the ubiquitin system Ubiquitin conjugation is known to target protein substrates primarily to degradation by the proteasome or via the endocytic route. Here we describe a novel protein modification pathway in yeast which mediates the conjugation of RUB1, a ubiquitin‐like protein displaying 53% amino acid identity to ubiquitin. We show that RUB1 conjugation requires at least three proteins in vivo. ULA1 and UBA3 are related to the N‐ and C‐terminal domains of the E1 ubiquitin‐activating enzyme, respectively, and together fulfil E1‐like functions for RUB1 activation. RUB1 conjugation also requires UBC12, a protein related to E2 ubiquitin‐conjugating enzymes, which functions analogously to E2 enzymes in RUB1–protein conjugate formation. Conjugation of RUB1 is not essential for normal cell growth and appears to be selective for a small set of substrates. Remarkably, CDC53/cullin, a common subunit of the multifunctional SCF ubiquitin ligase, was found to be a major substrate for RUB1 conjugation. This suggests that the RUB1 conjugation pathway is functionally affiliated to the ubiquitin–proteasome system and may play a regulatory role. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png The EMBO Journal Wiley

A novel protein modification pathway related to the ubiquitin system

Loading next page...
 
/lp/wiley/a-novel-protein-modification-pathway-related-to-the-ubiquitin-system-0nhXXmQEL1

References (72)

Publisher
Wiley
Copyright
Copyright © 2013 Wiley Periodicals, Inc
ISSN
0261-4189
eISSN
1460-2075
DOI
10.1093/emboj/17.8.2208
pmid
9545234
Publisher site
See Article on Publisher Site

Abstract

Ubiquitin conjugation is known to target protein substrates primarily to degradation by the proteasome or via the endocytic route. Here we describe a novel protein modification pathway in yeast which mediates the conjugation of RUB1, a ubiquitin‐like protein displaying 53% amino acid identity to ubiquitin. We show that RUB1 conjugation requires at least three proteins in vivo. ULA1 and UBA3 are related to the N‐ and C‐terminal domains of the E1 ubiquitin‐activating enzyme, respectively, and together fulfil E1‐like functions for RUB1 activation. RUB1 conjugation also requires UBC12, a protein related to E2 ubiquitin‐conjugating enzymes, which functions analogously to E2 enzymes in RUB1–protein conjugate formation. Conjugation of RUB1 is not essential for normal cell growth and appears to be selective for a small set of substrates. Remarkably, CDC53/cullin, a common subunit of the multifunctional SCF ubiquitin ligase, was found to be a major substrate for RUB1 conjugation. This suggests that the RUB1 conjugation pathway is functionally affiliated to the ubiquitin–proteasome system and may play a regulatory role.

Journal

The EMBO JournalWiley

Published: Mar 15, 1999

Keywords: ; ; ; ;

There are no references for this article.