Ube2w and ataxin-3 coordinately regulate the ubiquitin ligase CHIP.

Published

Journal Article

The mechanisms by which ubiquitin ligases are regulated remain poorly understood. Here we describe a series of molecular events that coordinately regulate CHIP, a neuroprotective E3 implicated in protein quality control. Through their opposing activities, the initiator E2, Ube2w, and the specialized deubiquitinating enzyme (DUB), ataxin-3, participate in initiating, regulating, and terminating the CHIP ubiquitination cycle. Monoubiquitination of CHIP by Ube2w stabilizes the interaction between CHIP and ataxin-3, which through its DUB activity limits the length of chains attached to CHIP substrates. Upon completion of substrate ubiquitination, ataxin-3 deubiquitinates CHIP, effectively terminating the reaction. Our results suggest that functional pairing of E3s with ataxin-3 or similar DUBs represents an important point of regulation in ubiquitin-dependent protein quality control. In addition, the results shed light on disease pathogenesis in SCA3, a neurodegenerative disorder caused by polyglutamine expansion in ataxin-3.

Full Text

Duke Authors

Cited Authors

  • Scaglione, KM; Zavodszky, E; Todi, SV; Patury, S; Xu, P; Rodríguez-Lebrón, E; Fischer, S; Konen, J; Djarmati, A; Peng, J; Gestwicki, JE; Paulson, HL

Published Date

  • August 2011

Published In

Volume / Issue

  • 43 / 4

Start / End Page

  • 599 - 612

PubMed ID

  • 21855799

Pubmed Central ID

  • 21855799

Electronic International Standard Serial Number (EISSN)

  • 1097-4164

International Standard Serial Number (ISSN)

  • 1097-2765

Digital Object Identifier (DOI)

  • 10.1016/j.molcel.2011.05.036

Language

  • eng