A novel role for XIAP in copper homeostasis through regulation of MURR1.

Journal Article (Journal Article)

XIAP is a potent suppressor of apoptosis that directly inhibits specific members of the caspase family of cysteine proteases. Here we demonstrate a novel role for XIAP in the control of intracellular copper levels. XIAP was found to interact with MURR1, a factor recently implicated in copper homeostasis. XIAP binds to MURR1 in a manner that is distinct from that utilized by XIAP to bind caspases, and consistent with this, MURR1 did not affect the antiapoptotic properties of XIAP. However, cells and tissues derived from Xiap-deficient mice were found to contain reduced copper levels, while suppression of MURR1 resulted in increased intracellular copper in cultured cells. Consistent with these opposing effects, XIAP was observed to negatively regulate MURR1 protein levels by the formation of K48 polyubiquitin chains on MURR1 that promote its degradation. These findings represent the first described phenotypic alteration in Xiap-deficient mice and demonstrate that XIAP can function through MURR1 to regulate copper homeostasis.

Full Text

Duke Authors

Cited Authors

  • Burstein, E; Ganesh, L; Dick, RD; van De Sluis, B; Wilkinson, JC; Klomp, LWJ; Wijmenga, C; Brewer, GJ; Nabel, GJ; Duckett, CS

Published Date

  • January 14, 2004

Published In

Volume / Issue

  • 23 / 1

Start / End Page

  • 244 - 254

PubMed ID

  • 14685266

Pubmed Central ID

  • PMC1271669

International Standard Serial Number (ISSN)

  • 0261-4189

Digital Object Identifier (DOI)

  • 10.1038/sj.emboj.7600031


  • eng

Conference Location

  • England