Cdc37/Hsp90 protein-mediated regulation of IRE1α protein activity in endoplasmic reticulum stress response and insulin synthesis in INS-1 cells.

Journal Article (Journal Article)

IRE1α is an endoplasmic reticulum (ER) localized signaling molecule critical for unfolded protein response. During ER stress, IRE1α activation is induced by oligomerization and autophosphorylation in its cytosolic domain, a process triggered by dissociation of an ER luminal chaperone, binding immunoglobulin-protein (BiP), from IRE1α. In addition, inhibition of a cytosolic chaperone protein Hsp90 also induces IRE1α oligomerization and activation in the absence of an ER stressor. Here, we report that the Hsp90 cochaperone Cdc37 directly interacts with IRE1α through a highly conserved cytosolic motif of IRE1α. Cdc37 knockdown or disruption of Cdc37 interaction with IRE1α significantly increased basal IRE1α activity. In INS-1 cells, Hsp90 inhibition and disruption of IRE1α-Cdc37 interaction both induced an ER stress response and impaired insulin synthesis and secretion. These data suggest that Cdc37-mediated direct interaction between Hsp90/Cdc37 and an IRE1α cytosolic motif is important to maintain basal IRE1α activity and contributes to normal protein homeostasis and unfolded protein response under physiological stimulation.

Full Text

Duke Authors

Cited Authors

  • Ota, A; Wang, Y

Published Date

  • February 24, 2012

Published In

Volume / Issue

  • 287 / 9

Start / End Page

  • 6266 - 6274

PubMed ID

  • 22199355

Pubmed Central ID

  • PMC3307264

Electronic International Standard Serial Number (EISSN)

  • 1083-351X

Digital Object Identifier (DOI)

  • 10.1074/jbc.M111.331264

Language

  • eng

Conference Location

  • United States