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The Grb10/Nedd4 complex regulates ligand-induced ubiquitination and stability of the insulin-like growth factor I receptor. Mol Cell Biol 2003 May;23(9):3363-72

Date

04/17/2003

Pubmed ID

12697834

Pubmed Central ID

PMC153198

DOI

10.1128/MCB.23.9.3363-3372.2003

Scopus ID

2-s2.0-0345381737   203 Citations

Abstract

The adapter protein Grb10 belongs to a superfamily of related proteins, including Grb7, -10, and -14 and Caenorhabditis elegans Mig10. Grb10 is an interacting partner of the insulin-like growth factor I receptor (IGF-IR) and the insulin receptor (IR). Previous work showed an inhibitory effect of mouse Grb10 (mGrb10alpha) on IGF-I-mediated mitogenesis (A. Morrione et al., J. Biol. Chem. 272:26382-26387, 1997). With mGrb10alpha as bait in a yeast two-hybrid screen, mouse Nedd4 (mNedd4-1), a ubiquitin protein ligase, was previously isolated as an interacting protein of Grb10 (A. Morrione et al., J. Biol. Chem. 274:24094-24099, 1999). However, Grb10 is not ubiquitinated by Nedd4 in cells. Here we show that in mouse embryo fibroblasts overexpressing Grb10 and the IGF-IR (p6/Grb10), there is a strong ligand-dependent increase in ubiquitination of the IGF-IR compared with that in parental cells (p6). This increased ubiquitination is associated with a shorter half-life and increased internalization of the IGF-IR. The IGF-IR is stabilized following treatment with both MG132 and chloroquine, indicating that both the proteasome and lysosomal pathways mediate degradation of the receptor. Ubiquitination of the IGF-IR likely occurs at the plasma membrane, prior to the formation of endocytic vesicles, as it is insensitive to dansylcadaverine, an inhibitor of early endosome formation in IGF-IR endocytosis. Grb10 coimmunoprecipitates with the IGF-IR and endogenous Nedd4 in p6/Grb10 cells, suggesting the presence of a Grb10/Nedd4/IGF-IR complex. Ubiquitination of the IGF-IR in p6/Grb10 cells is severely impaired by overexpression of a catalytically inactive Nedd4 mutant (Nedd4-CS), which also stabilizes the receptor. Likewise, overexpression of a Grb10 mutant lacking the Src homology 2 (SH2) domain impaired ubiquitination of the IGF-IR in parental p6 and p6/Grb10 cells, indicating that Grb10 binding to Nedd4 is critical for ubiquitination of the receptor. These results suggest a role for the Grb10/Nedd4 complex in regulating ubiquitination and stability of the IGF-IR, and they suggest that Grb10 serves as an adapter to form a bridge between Nedd4 and the IGF-IR. This is the first demonstration of regulation of stability of a tyrosine kinase receptor by the Nedd4 (HECT) family of E3 ligases.

Author List

Vecchione A, Marchese A, Henry P, Rotin D, Morrione A

Author

Adriano Marchese PhD Professor in the Biochemistry department at Medical College of Wisconsin




MESH terms used to index this publication - Major topics in bold

Animals
Calcium-Binding Proteins
Cell Membrane
Cells, Cultured
Chloroquine
Cysteine Endopeptidases
Cysteine Proteinase Inhibitors
Endosomal Sorting Complexes Required for Transport
Fibroblasts
GRB10 Adaptor Protein
Gene Expression
Insulin-Like Growth Factor I
Leupeptins
Ligands
Ligases
Lysosomes
Macromolecular Substances
Mice
Multienzyme Complexes
Mutation
Nedd4 Ubiquitin Protein Ligases
Precipitin Tests
Proteasome Endopeptidase Complex
Proteins
Receptor, IGF Type 1
Recombinant Proteins
Transport Vesicles
Ubiquitin
Ubiquitin-Protein Ligases
src Homology Domains