Linked Life Data

18632619

Source:http://linkedlifedata.com/resource/pubmed/id/18632619

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
14
pubmed:dateCreated
2008-7-17
pubmed:abstractText
The insulin-like growth factor receptor (IGF-IR) plays several pivotal roles in cancer. Although most studies on the function of the IGF-IR have been attributed to kinase-dependent signaling, recent findings by our group and others have implicated biological roles mediated by ubiquitination of the receptor. As previously reported, the E3 ligases Mdm2 and Nedd4 mediate IGF-IR ubiquitination. Here we show that c-Cbl is a novel E3 ligase for IGF-IR. On ligand stimulation, both Mdm2 and c-Cbl associate with IGF-IR and mediate receptor polyubiquitination. Whereas Mdm2 catalyzed lysine 63 (K63) chain ubiquitination, c-Cbl modified IGF-IR through K48 chains. Mdm2-mediated ubiquitination occurred when cells were stimulated with a low concentration (5 ng/mL) of IGF-I, whereas c-Cbl required high concentrations (50-100 ng/mL). Mdm2-ubiquitinated IGF-IR was internalized through the clathrin endocytic pathway whereas c-Cbl-ubiquitinated receptors were endocytosed via the caveolin route. Taken together, our results show that c-Cbl constitutes a new ligase responsible for the ubiquitination of IGF-IR and that it complements the action of Mdm2 on ubiquitin lysine residue specificity, responsiveness to IGF-I, and type of endocytic pathway used. The actions and interactions of Mdm2 and c-Cbl in the ubiquitination and endocytosis of IGF-IR may have implications in cancer. In addition, identification and functional characterization of new E3 ligases are important in itself because therapeutic targeting of substrate-specific E3 ligases is likely to represent a critical strategy in future cancer treatment.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
1538-7445
pubmed:author
pubmed:issnType
Electronic
pubmed:day
15
pubmed:volume
68
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5669-77
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Identification of c-Cbl as a new ligase for insulin-like growth factor-I receptor with distinct roles from Mdm2 in receptor ubiquitination and endocytosis.
pubmed:affiliation
Department of Oncology and Pathology, Karolinska Institutet, Cancer Center Karolinska, Karolinska University Hospital, Stockholm, Sweden.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't