Affordable Access

deepdyve-link
Publisher Website

Ca 2+-induced release of mitochondrial m-calpain from outer membrane with binding of calpain small subunit and Grp75

Authors
  • Ozaki, Taku
  • Yamashita, Tetsuro
  • Ishiguro, Sei-ichi
Type
Published Article
Journal
Archives of Biochemistry and Biophysics
Publisher
Elsevier BV
Publication Date
Jan 01, 2010
Volume
507
Issue
2
Pages
254–261
Identifiers
DOI: 10.1016/j.abb.2010.12.003
Source
Elsevier
Keywords
License
Unknown

Abstract

Although mitochondrial μ- and m-calpains play significant roles in apoptotic cell death, their activating mechanisms have not been determined. The purpose of this study was to determine the core factors that are involved in activating mitochondrial outer membrane (OM)-bound calpains. To accomplish this, we solubilized OM-bound calpains and separated them by DEAE-Sepharose column chromatography, and identified them by immunoblots. We also determined the core factors that activated the OM-bound calpains and release them from the OM by calpain assays, immunoprecipitations, and immunoblots. The OM-bound m-calpain large subunit was not associated with the small subunit or with Grp75 chaperone. Free calpain small subunit was located in the IMS and caused the release of the OM-bound m-calpain large subunit from the OM together with Grp75, ATP, and Ca 2+. Our results showed that the activating mechanism of mitochondrial OM-bound m-calpain and the release of mitochondrial m-calpain from the OM have important implications in facilitating apoptotic cell death.

Report this publication

Statistics

Seen <100 times