Format

Send to

Choose Destination
PLoS One. 2012;7(11):e49428. doi: 10.1371/journal.pone.0049428. Epub 2012 Nov 7.

Cbl-c ubiquitin ligase activity is increased via the interaction of its RING finger domain with a LIM domain of the paxillin homolog, Hic 5.

Author information

1
Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America.

Abstract

Cbl proteins (Cbl, Cbl-b and Cbl-c) are ubiquitin ligases that are critical regulators of tyrosine kinase signaling. In this study we identify a new Cbl-c interacting protein, Hydrogen peroxide Induced Construct 5 (Hic-5). The two proteins interact through a novel interaction mediated by the RING finger of Cbl-c and the LIM2 domain of Hic-5. Further, this interaction is mediated and dependent on specific zinc coordinating complexes within the RING finger and LIM domain. Binding of Hic-5 to Cbl-c leads to an increase in the ubiquitin ligase activity of Cbl-c once Cbl-c has been activated by Src phosphorylation or through an activating phosphomimetic mutation. In addition, co-transfection of Hic-5 with Cbl-c leads to an increase in Cbl-c mediated ubiquitination of the EGFR. These data suggest that Hic-5 enhances Cbl-c ubiquitin ligase activity once Cbl-c has been phosphorylated and activated. Interactions between heterologous RING fingers have been shown to activate E3s. This is the first demonstration of enhancement of ubiquitin ligase activity of a RING finger ubiquitin ligase by the direct interaction of a LIM zinc coordinating domain.

PMID:
23145173
PMCID:
PMC3492284
DOI:
10.1371/journal.pone.0049428
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Public Library of Science Icon for PubMed Central
Loading ...
Support Center