Increased expression of co-chaperone HOP with HSP90 and HSC70 and complex formation in human colonic carcinoma.
Co-chaperone HOP (also called stress-inducible protein 1) is a co-chaperone that interacts with the cytosolic 70-kDa heat shock protein (HSP70) and 90-kDa heat shock protein (HSP90) families using different tetratricopeptide repeat domains. HOP plays crucial roles in the productive folding of substrate proteins by controlling the chaperone activities of HSP70 and HSP90. Here, we examined the levels of HOP, HSC70 (cognate of HSP70, also called HSP73), and HSP90 in the tumor tissues from colon cancer patients, in comparison with the non-tumor tissues from the same patients. Expression level of HOP was significantly increased in the tumor tissues (68% of patients, n = 19). Levels of HSC70 and HSP90 were also increased in the tumor tissues (95% and 74% of patients, respectively), and the HOP level was highly correlated with those of HSP90 (r = 0.77, p < 0.001) and HSC70 (r = 0.68, p < 0.01). Immunoprecipitation experiments indicated that HOP complexes with HSC70 or HSP90 in the tumor tissues. These data are consistent with increased formation of co-chaperone complexes in colon tumor specimens compared to adjacent normal tissue and could reflect a role for HOP in this process.
Kubota
Hiroshi
H
Department of Life Science, Faculty and Graduate School of Engineering and Resource Science, Akita University, 1-1 Tegata-Gakuencho, Akita, 010-8502, Japan.
Yamamoto
Soh
S
Itoh
Eri
E
Abe
Yuki
Y
Nakamura
Asami
A
Izumi
Yukina
Y
Okada
Hirotaka
H
Iida
Masatake
M
Nanjo
Hiroshi
H
Itoh
Hideaki
H
Yamamoto
Yuzo
Y
D016227:Benzoquinones / Q000494:pharmacology; D002277:Carcinoma / Q000378:metabolism* / Q000473:pathology; D003110:Colonic Neoplasms / Q000378:metabolism* / Q000473:pathology; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism*; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism*; D006360:Heat-Shock Proteins / Q000378:metabolism*; D006801:Humans; D047468:Immunoprecipitation; D047029:Lactams, Macrocyclic / Q000494:pharmacology; D011485:Protein Binding; D017510:Protein Folding
D016227:Benzoquinones; D018840:HSP70 Heat-Shock Proteins; D018841:HSP90 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D047029:Lactams, Macrocyclic; C079373:STIP1 protein, human; C112765:tanespimycin