Spred-2 steady-state levels are regulated by phosphorylation and Cbl-mediated ubiquitination

被引：10

作者：

Lock, Peter ^{[1
]}

I, Stacey T. T. ^{[1
]}

Straffon, F. L. ^{[1
]}

Schieb, Heinke ^{[1
]}

Hovens, Christopher M. ^{[1
]}

Stylli, Stanley S. ^{[1
]}

机构：

[1] Univ Melbourne, Royal Melbourne Hosp, Dept Surg, Cell Signaling Lab, Melbourne, Vic 3050, Australia

来源：

BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS | 2006年 / 351卷 / 04期

关键词：

Spred-2; Cbl; ubiquitination; phosphorylation;

D O I：

10.1016/j.bbrc.2006.10.150

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

Spred proteins modulate growth factor receptor signaling by inhibiting the Ras-MAPK cascade. Here, we show that Spred-1, Spred-2, and Spred-3 are ubiquitinated in HEK293T cells stimulated with epidermal growth factor (EGF) or pervanadate. Spred-2 tyrosines Y228 and/or Y231 in the Kit binding domain were identified as putative phosphorylation site(s) critical for Spred-2 ubiquitination. Depletion of Cbl and Cbl-b E3 ubiquitin ligases by RNA interference, or overexpression of a Cbl dominant inhibitory mutant (Cbl-N), inhibited Spred-2 ubiquitination, while conversely, wild type Cbl enhanced Spred-2 ubiquitination. Interaction of Spred-2 with Cbl-N was detectable by co-immunoprecipitation and required the Cbl SH2 domain and Spred-2 Y228 and Y231 residues. Studies on endogenous Spred-2 in ME4405 melanoma cells showed that pervanadate induced Spred-2 ubiquitination and a marked reduction in Spred-2 steady-state levels that was partially blocked by the proteasomal inhibitor, MG-132. These results suggest a role for Spred-2 tyrosine phosphorylation and ubiquitination in controlling Spred-2 expression levels. (c) 2006 Elsevier Inc. All rights reserved.

引用

页码：1018 / 1023

页数：6

共 36 条

[1] Met/hepatocyte growth factor receptor ubiquitination suppresses transformation and is required for Hrs phosphorylation [J].