Phosphorylation of microsomal HMG CoA reductase increases susceptibility to proteolytic degradation in vitro

Rex A. Parker, Steven J. Miller, David M. Gibson

Research output: Contribution to journalArticle

30 Scopus citations


Conversion of native, 97-100 kDa rat liver microsomal HMG CoA reductase to membrane-bound 62 kDa and soluble 52-56 kDa catalytically active forms was catalyzed invitro by the calcium-dependent, leupeptin- and calpastatin-sensitive protease calpain-II purified from rat liver cytosol. Cleavage of the native 97-100 kDa reductase was enhanced by pretreatment (inactivation) of microsomes with ATP(Mg2+) and liver reductase kinase (compared to protein phosphatase-pretreated controls). This was reflected in a loss of the 97-100 kDa species and an increase in the soluble 52-56 kDa species (total enzyme activity and specific immunoblot recovery).

Original languageEnglish (US)
Pages (from-to)629-635
Number of pages7
JournalBiochemical and Biophysical Research Communications
Issue number2
StatePublished - Dec 14 1984


ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology
  • Cell Biology

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