FBW2 targets GCMa to the ubiquitin-proteasome degradation system.

Journal Article (Journal Article)

The GCM proteins GCMa/1 and GCMb/2 are novel zinc-containing transcription factors critical for glial cell differentiation in fly and for placental as well as parathyroid gland development in mouse. Previous pulse-chase experiments have demonstrated differential protein stabilities of GCM proteins with half-lives from approximately 30 min to 2 h (Tuerk, E. E., Schreiber, J., and Wegner, M. (2000) J. Biol. Chem. 275, 4774-4782). However, little is known about the machinery that controls GCM protein degradation. Here, we report the identification of an SCF complex as the GCM ubiquitin-protein isopeptide ligase (E3) that regulates human GCMa (hGCMa) degradation. We found that SKP1 and CUL1, two key components of the SCF complex, associate with hGCMa in vivo. We further identify the human F-box protein FBW2 (hFBW2) as the substrate recognition subunit in the SCF E3 complex for hGCMa. We show that hFBW2 interacts with hGCMa in a phosphorylation-dependent manner and promotes hGCMa ubiquitination. Supporting a critical role for hFBW2 in hGCMa degradation, knockdown of hFBW2 expression by RNA interference leads to a reduction in hGCMa ubiquitination and a concomitant increase in hGCMa protein stability. Our study identifies the SCF(hFBW2) E3 complex as the key machinery that targets hGCMa to the ubiquitin-proteasome degradation system.

Full Text

Duke Authors

Cited Authors

  • Yang, C-S; Yu, C; Chuang, H-C; Chang, C-W; Chang, G-D; Yao, T-P; Chen, H

Published Date

  • March 18, 2005

Published In

Volume / Issue

  • 280 / 11

Start / End Page

  • 10083 - 10090

PubMed ID

  • 15640526

International Standard Serial Number (ISSN)

  • 0021-9258

Digital Object Identifier (DOI)

  • 10.1074/jbc.M413986200


  • eng

Conference Location

  • United States