High impact information on CPR7

• Cpr6 and Cpr7, the Saccharomyces cerevisiae homologs of cyclophilin-40 (CyP-40), were shown to form complexes with Hsp90, a protein chaperone that functions in several signal transduction pathways [1].
• The open reading frame YBR155w, which has moderate identity to the yeast p60 homolog STI1, was isolated as a high-copy-number suppressor of the cpr7 slow-growth phenotype [2].
• Yeast strains lacking the Cpr7 enzyme are viable but exhibit a slow-growth phenotype [2].
• In addition, we show here that cpr7 mutant strains are hypersensitive to the Hsp90 inhibitor geldanamycin [2].
• In addition, it has recently been shown that Cpr7 plays a major role in negative regulation of the S. cerevisiae heat shock transcription factor (HSF) [3].

Biological context of CPR7

• Neither CPR6 nor CPR7 is essential but deletion of CPR7 results in a significant impairment of the rate of cell division [4].
• Our results reveal that Hsp90 and Cpr7 are required for negative regulation of the heat shock response under both stress and nonstress conditions and establish a specific endogenous role for the Hsp90 machinery in S. cerevisiae [5].
• Ah receptor signalling from a lacZ reporter gene was reduced by approximately 60% in cells that lacked Cpr7 [6].

Associations of CPR7 with chemical compounds

• Cpr7 is required for normal growth and is required for maximal activity of heterologous Hsp90-dependent substrates, including glucocorticoid receptor (GR) and the oncogenic tyrosine kinase pp60(v-src) [3].

Physical interactions of CPR7

• Although both co-chaperones interact with Hsp90 primarily through the carboxyl terminus (EEVD), Cns1 and Cpr7 are mostly found in complexes distinct from Hsp90 [7].

Other interactions of CPR7

• We report the analysis of two Saccharomyces cerevisiae cyclophilins, Cpr6 and Cpr7, identified by their ability to interact in vivo with the transcriptional regulator Rpd3 [4].
• Finally, we show that Cns1 functions in MAP kinase signaling in association with Cpr7 [8].
• Consistent with this, the half-life of Mal63p is significantly shorter in the hsc82 Delta cpr7 Delta strain (reduced about 6-fold) and modestly affected in the Hsp90-ts strain (reduced about 2-fold) [9].

Analytical, diagnostic and therapeutic context of CPR7

• The activities of two heterologous Hsp90-dependent signal transducers expressed in yeast, glucocorticoid receptor and pp60(v-src) kinase, were adversely affected by cpr7 null mutations [1].

References