| Literature DB >> 9223278 |
K Tashiro1, M P Pando, Y Kanegae, P M Wamsley, S Inoue, I M Verma.
Abstract
The NF-kappaB/Rel proteins are sequestered in the cytoplasm in association with IkappaBalpha. In response to external signals, IkappaBalpha is phosphorylated, multi-ubiquitinated, and degraded by proteasomes, thereby releasing NF-kappaB/Rel proteins to migrate to the nucleus. We have cloned a mouse ubiquitin-conjugating enzyme (mE2), which associates with IkappaBalpha. mE2 is homologous to the yeast Ubc9/Hus5 ubiquitin-conjugating enzyme. A transdominant-negative mutant of mE2 had no effect on phosphorylation of IkappaBalpha, but delayed its degradation. Correspondingly, tumor necrosis factor-alpha-inducible NF-kappaB activity was diminished. We propose that mE2 is directly involved in the ubiquitin conjugation of IkappaBalpha, a pivotal step in its degradation pathway.Entities:
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Year: 1997 PMID： 9223278 PMCID： PMC21520 DOI： 10.1073/pnas.94.15.7862
Source DB: PubMed Journal: Proc Natl Acad Sci U S A ISSN： 0027-8424 Impact factor: 11.205