Linked Life Data

20351172

Source:http://linkedlifedata.com/resource/pubmed/id/20351172

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
2010-5-12
pubmed:abstractText
Although the BRCA1 tumor suppressor has been implicated in many cellular processes, the biochemical mechanisms by which it influences these diverse pathways are poorly understood. The only known enzymatic function of BRCA1 is the E3 ubiquitin ligase activity mediated by its highly conserved RING domain. In vivo, BRCA1 associates with the BARD1 polypeptide to form a heterodimeric BRCA1/BARD1 complex that catalyzes autoubiquitination of BRCA1 and trans ubiquitination of other protein substrates. In most cases, BRCA1-dependent ubiquitination generates polyubiquitin chains bearing an unconventional K6 linkage that does not appear to target proteins for proteasomal degradation. Since ubiquitin-dependent processes are usually mediated by cellular receptors with ubiquitin-binding motifs, we screened for proteins that specifically bind autoubiquitinated BRCA1. Here we report that the UBXN1 polypeptide, which contains a ubiquitin-associated (UBA) motif, recognizes autoubiquitinated BRCA1. This occurs through a bipartite interaction in which the UBA domain of UBXN1 binds K6-linked polyubiquitin chains conjugated to BRCA1 while the C-terminal sequences of UBXN1 bind the BRCA1/BARD1 heterodimer in a ubiquitin-independent fashion. Significantly, the E3 ligase activity of BRCA1/BARD1 is dramatically reduced in the presence of UBXN1, suggesting that UBXN1 regulates the enzymatic function of BRCA1 in a manner that is dependent on its ubiquitination status.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
1098-5549
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
30
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2787-98
pubmed:dateRevised
2011-3-3
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
The UBXN1 protein associates with autoubiquitinated forms of the BRCA1 tumor suppressor and inhibits its enzymatic function.
pubmed:affiliation
Institute for Cancer Genetics, Columbia University Medical Center, Irving Cancer Research Center, Rm. 503A, 1130 St. Nicholas Avenue, New York, NY 10032, USA.
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural