Linked Life Data

16951183

Source:http://linkedlifedata.com/resource/pubmed/id/16951183

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
17
pubmed:dateCreated
2006-9-4
pubmed:abstractText
The steroid receptor coactivator oncogene, amplified in breast cancer 1 (AIB1; also known as ACTR/RAC-3/TRAM-1/SRC-3/p/CIP), is amplified and overexpressed in a variety of epithelial tumors. AIB1 has been reported to have roles in both steroid-dependent and steroid-independent transcription during tumor progression. In this report, we describe that the cellular levels of AIB1 are controlled through regulated proteasomal degradation. We found that serum withdrawal or growth in high cell density caused rapid degradation of AIB1 protein, but not mRNA, in immortalized cell lines. Proteasome inhibitors prevented this process, and high molecular weight ubiquitylated species of AIB1 were detected. Nuclear export was required for proteasomal degradation of AIB1 and involved the ubiquitin ligase, E6AP. AIB1/E6AP complexes were detected in cellular extracts, and reduction of cellular E6AP levels with E6AP short interfering RNA prevented proteasomal degradation of AIB1. Conversely, overexpression of E6AP promoted AIB1 degradation. The COOH terminus of AIB1 interacted with E6AP in vitro and deletion of this region in AIB1 rendered it resistant to degradation in cells. From our results, we propose a model whereby signals promoted by changes in the cellular milieu initiate E6AP-mediated proteasomal degradation of AIB1 and thus contribute to the control of steady-state levels of this protein.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
1538-7445
pubmed:author
pubmed:issnType
Electronic
pubmed:day
1
pubmed:volume
66
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
8680-6
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:16951183-Breast Neoplasms, pubmed-meshheading:16951183-Carcinoma, Squamous Cell, pubmed-meshheading:16951183-Cell Line, pubmed-meshheading:16951183-Cell Line, Transformed, pubmed-meshheading:16951183-Cell Line, Tumor, pubmed-meshheading:16951183-Culture Media, Serum-Free, pubmed-meshheading:16951183-Female, pubmed-meshheading:16951183-Gene Expression Regulation, Neoplastic, pubmed-meshheading:16951183-Histone Acetyltransferases, pubmed-meshheading:16951183-Humans, pubmed-meshheading:16951183-Kidney, pubmed-meshheading:16951183-Nuclear Receptor Coactivator 3, pubmed-meshheading:16951183-Plasmids, pubmed-meshheading:16951183-Proteasome Endopeptidase Complex, pubmed-meshheading:16951183-RNA, Small Interfering, pubmed-meshheading:16951183-Trans-Activators, pubmed-meshheading:16951183-Transfection, pubmed-meshheading:16951183-Ubiquitin, pubmed-meshheading:16951183-Ubiquitin-Protein Ligases
pubmed:year
2006
pubmed:articleTitle
E6AP mediates regulated proteasomal degradation of the nuclear receptor coactivator amplified in breast cancer 1 in immortalized cells.
pubmed:affiliation
Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC 20007, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, N.I.H., Extramural, Research Support, N.I.H., Intramural