Rabbit FKBP59-heat shock protein binding immunophillin (HBI) is a calmodulin binding protein

Massol, Nelly; Lebeau, Marie‐Claire; Renoir, Jack‐Michel; Faber, Lee E.; Baulieu, Étienne-Émile

doi:10.1016/0006-291x(92)90448-t

Cited by 72 publications

(39 citation statements)

References 26 publications

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“…For example, both CaM and S100A1 bind to twitchin kinase, but only S100A1 activates the enzyme. In the present study, Hsp90, Hsp70, FKBP52, and CyP40 weakly bound to CaM-Sepharose in the presence and absence of Ca 2ϩ (data not shown) similar to that reported previously (17,18), although nonspecific interactions cannot be excluded. S100 proteins (ϳ20 known so far) show a very divergent pattern of cell-and tissue-specific expression consistent with their pleiotropic intracellular functions (19,46).…”

Section: Discussionsupporting

confidence: 92%

“…Although it has been reported previously that CaM, a prototypical Ca 2ϩ sensor, binds to Hsp90 (15), Hsp70 (16), FKBP52 (17), and CyP40 (18), the regulatory function of CaM has been a conundrum. To establish whether CaM or S100 proteins exhibit properties of molecular chaperones, we examined their interaction with the components of the chaperone complex.…”

Section: Discussionmentioning

confidence: 99%

“…Selective adsorption of the GST fusion proteins onto glutathione-Sepharose allowed the resin to be used in affinity chromatography to screen for proteins, which would target the chaperone and cochaperone proteins. We performed in vitro binding assays using GST-truncated Hsp90, GST-truncated Hsp70, GST-FKBP52, and GST-CyP40 fusion proteins to confirm the interactions between CaM and the chaperone and cochaperone proteins described in previous reports (15)(16)(17)(18) and exclude the possibility that these interactions were indirect or nonspecific. We also analyzed binding of S100 proteins to the chaperone and cochaperone proteins, because the binding properties of CaM and S100 proteins often overlap (19).…”

Section: Materials-fluphenazine (4-[3-[2-(trifluoromethyl)-10hmentioning

confidence: 99%

“…The intensity of light emission from the assay was determined for 20 s with Luminoskan with a 100:50-l ratio mixture of the luciferase assay reagents and cell lysate. (15)(16)(17)(18). Truncated Hsp90-(237-628), truncated Hsp70-(1-382), full-length FKBP52, and full-length CyP40 were expressed as fusion proteins with GST.…”

Section: Materials-fluphenazine (4-[3-[2-(trifluoromethyl)-10hmentioning

confidence: 99%

“…Among such proteins, it is well known that calmodulin (CaM) is involved in many aspects of the Ca 2ϩ regulating system in various cell types (14). Although several reports indicate that CaM binds to Hsp90 (15), Hsp70 (16), FKBP52 (17), and CyP40 (18) in a Ca 2ϩ -dependent or -independent manner, the regulating role of CaM remains unclear. The overlapping specificity of CaM and S100 proteins for the interaction with target proteins has been reported (19).…”

mentioning

confidence: 99%

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S100A1 Is a Novel Molecular Chaperone and a Member of the Hsp70/Hsp90 Multichaperone Complex

Okada

Hatakeyama

Itoh

et al. 2004

Journal of Biological Chemistry

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Although calmodulin is known to be a component of the Hsp70/Hsp90 multichaperone complex, the functional role of the protein remains uncertain. In this study, we have identified S100A1, but not calmodulin or other S100 proteins, as a potent molecular chaperone and a new member of the multichaperone complex. Glutathione S-transferase pull-down assays and co-immunoprecipitation experiments indicated the formation of stable complexes between S100A1 and Hsp90, Hsp70, FKBP52, and CyP40 both in vitro and in mammalian cells. S100A1 potently protected citrate synthase, aldolase, glyceraldehyde-3-phosphate dehydrogenase, and rhodanese from heat-induced aggregation and suppressed the aggregation of chemically denatured rhodanese and citrate synthase during the refolding pathway. In addition, S100A1 suppressed the heat-induced inactivation of citrate synthase activity, similar to that for Hsp90 and p23. The chaperone activity of S100A1 was antagonized by calmodulin antagonists, such as fluphenazine and prenylamine, that is, indeed an intrinsic function of the protein. The overexpression of S100A1 in COS-7 cells protected transiently expressed firefly luciferase and Escherichia coli ␤-galactosidase from inactivation during heat shock. The results demonstrate a novel physiological function for S100A1 and bring us closer to a comprehensive understanding of the molecular mechanisms of the Hsp70/Hsp90 multichaperone complex.

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