Linked Life Data

14707120

Source:http://linkedlifedata.com/resource/pubmed/id/14707120

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
2004-3-15
pubmed:abstractText
The homologue of Slimb (HOS) F-box protein is a receptor of the Skp1-Cullin1-F-box protein (SCF(HOS)) E3 ubiquitin ligase, which mediates ubiquitination and degradation of beta-catenin and the inhibitor of NFkappaB, IkappaB. We found that HOS itself is an unstable protein that undergoes ubiquitination and degradation in a 26 S proteasome-dependent manner. A HOS mutant lacking the F-box that is deficient in binding to the core SCF components underwent ubiquitination less efficiently and was more stable than the wild type protein. Furthermore, ubiquitination and degradation of HOS was impaired in ts41 cells, in which the activities of Cullin-based ligases were decreased because the NEDD8 pathway was abrogated. Whereas HOS was directly ubiquitinated within the SCF(HOS) complex in vitro, the addition of phosphorylated IkappaBalpha inhibited this ubiquitination. Increasing cellular levels of HOS substrate (phosphorylated IkappaBalpha) by activating IkappaB kinase inhibited HOS ubiquitination and led to stabilization of HOS, indicating that interaction between HOS and its substrate might protect HOS from proteolysis. Taken together, our data suggest that proteolysis of HOS depends on its interaction with active components of the SCF complex and that HOS stability is regulated by a bound substrate. These findings may define a mechanism for maintaining activities of specific SCF complexes based on availability of a particular substrate.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
19
pubmed:volume
279
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
11074-80
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Stability of homologue of Slimb F-box protein is regulated by availability of its substrate.
pubmed:affiliation
Department of Animal Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.