Linked Life Data

21378313

Source:http://linkedlifedata.com/resource/pubmed/id/21378313

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
Pt 6
pubmed:dateCreated
2011-3-7
pubmed:abstractText
BIM-extra long (BIM(EL)), a pro-apoptotic BH3-only protein and part of the BCL-2 family, is degraded by the proteasome following activation of the ERK1/2 signalling pathway. Although studies have demonstrated poly-ubiquitylation of BIM(EL) in cells, the nature of the ubiquitin chain linkage has not been defined. Using ubiquitin-binding domains (UBDs) specific for defined ubiquitin chain linkages, we show that BIM(EL) undergoes K48-linked poly-ubiquitylation at either of two lysine residues. Surprisingly, BIM(EL)?KK, which lacks both lysine residues, was not poly-ubiquitylated but still underwent ERK1/2-driven, proteasome-dependent turnover. BIM has been proposed to be an intrinsically disordered protein (IDP) and some IDPs can be degraded by uncapped 20S proteasomes in the absence of poly-ubiquitylation. We show that BIM(EL) is degraded by isolated 20S proteasomes but that this is prevented when BIM(EL) is bound to its pro-survival target protein MCL-1. Furthermore, knockdown of the proteasome cap component Rpn2 does not prevent BIM(EL) turnover in cells, and inhibition of the E3 ubiquitin ligase ?-TrCP, which catalyses poly-Ub of BIM(EL), causes Cdc25A accumulation but does not inhibit BIM(EL) turnover. These results provide new insights into the regulation of BIM(EL) by defining a novel ubiquitin-independent pathway for the proteasome-dependent destruction of this highly toxic protein.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1477-9137
pubmed:author
pubmed:issnType
Electronic
pubmed:day
15
pubmed:volume
124
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
969-77
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
BIM(EL), an intrinsically disordered protein, is degraded by 20S proteasomes in the absence of poly-ubiquitylation.
pubmed:affiliation
Laboratory of Molecular Signalling, The Babraham Institute, Babraham Research Campus, Cambridge, CB22 3AT, UK.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't