S100 proteins regulate the interaction of Hsp90 with Cyclophilin 40 and FKBP52 through their tetratricopeptide repeats

Seiko Shimamoto, Yasuo Kubota, Hiroshi Tokumitsu, Ryoji Kobayashi

Research output: Contribution to journalArticle

28 Citations (Scopus)


S100 proteins are a subfamily of the EF-hand type calcium sensing proteins, the exact biological functions of which have not been clarified yet. In this work, we have identified Cyclophilin 40 (CyP40) and FKBP52 (called immunophilins) as novel targets of S100 proteins. These immunophilins contain a tetratricopeptide repeat (TPR) domain for Hsp90 binding. Using glutathione-S transferase pull-down assays and immunoprecipitation, we have demonstrated that S100A1 and S100A2 specifically interact with the TPR domains of FKBP52 and CyP40 in a Ca2+-dependent manner, and lead to inhibition of the CyP40-Hsp90 and FKBP52-Hsp90 interactions. These findings have suggested that the Ca2+/S100 proteins are TPR-targeting regulators of the immunophilins-Hsp90 complex formations.

Original languageEnglish
Pages (from-to)1119-1125
Number of pages7
JournalFEBS Letters
Issue number6
Publication statusPublished - Mar 2010
Externally publishedYes



  • Cyclophilin 40
  • FKBP52
  • Hsp90
  • S100 proteins
  • Tetratricopeptide repeat

ASJC Scopus subject areas

  • Biochemistry
  • Biophysics
  • Cell Biology
  • Genetics
  • Molecular Biology
  • Structural Biology

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