Specific association of a set of molecular chaperones including HSP90 and Cdc37 with MOK, a member of the mitogen-activated protein kinase superfamily.
We have recently identified and cloned a novel member of mitogen-activated protein kinase superfamily protein, MOK (Miyata, Y., Akashi, M., and Nishida, E. (1999) Genes Cells 4, 299-309). To address its regulatory mechanisms, we searched for cellular proteins that specifically associate with MOK by co-immunoprecipitation experiments. Several cellular proteins including a major 90-kDa molecular chaperone HSP90 were found associated with MOK. Treatment of cells with geldanamycin, an HSP90-specific inhibitor, rapidly decreased the protein level of MOK, and the decrease was attributed to enhanced degradation of MOK through proteasome-dependent pathways. Our data suggest that the association with HSP90 may regulate intracellular protein stability and solubility of MOK. Experiments with a series of deletion mutants of MOK indicated that the region encompassing the protein kinase catalytic subdomains I-IV is required for HSP90 binding. Closely related protein kinases (male germ cell-associated kinase and male germ cell-associated kinase-related kinase) were also found to associate with HSP90, whereas conventional mitogen-activated protein kinases (extracellular signal-regulated kinase, p38, and c-Jun N-terminal kinase/stress-activated protein kinase) were not associated with HSP90. In addition, we found that other molecular chaperones including Cdc37, HSC70, HSP70, and HSP60 but not GRP94, FKBP52, or Hop were detected specifically in the MOK-HSP90 immunocomplexes. These results taken together suggest a role of a specific set of molecular chaperones in the stability of signal-transducing protein kinases.
Miyata
Y
Y
Department of Cell and Developmental Biology, Graduate School of Biostudies, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan.
Ikawa
Y
Y
Shibuya
M
M
Nishida
E
E
D000818:Animals; D000951:Antigens, Neoplasm; D016227:Benzoquinones; D001665:Binding Sites; D019556:COS Cells; D002352:Carrier Proteins; D018797:Cell Cycle Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D018833:Chaperonins; D002522:Chlorocebus aethiops; D003546:Cysteine Endopeptidases / Q000378:metabolism; D029721:Drosophila Proteins; D018840:HSP70 Heat-Shock Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D018841:HSP90 Heat-Shock Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D006801:Humans; D047029:Lactams, Macrocyclic; D008322:Mammals; D020928:Mitogen-Activated Protein Kinases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D018832:Molecular Chaperones / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D009097:Multienzyme Complexes / Q000378:metabolism; D016296:Mutagenesis; D046988:Proteasome Endopeptidase Complex; D011485:Protein Binding; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors; D011809:Quinones / Q000494:pharmacology; D051381:Rats; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D017384:Sequence Deletion; D014162:Transfection; D014982:Xenopus laevis
D000951:Antigens, Neoplasm; D016227:Benzoquinones; C498362:CDC37 protein, human; D002352:Carrier Proteins; C103269:Cdc37 protein, rat; D018797:Cell Cycle Proteins; D029721:Drosophila Proteins; D018840:HSP70 Heat-Shock Proteins; D018841:HSP90 Heat-Shock Proteins; D047029:Lactams, Macrocyclic; D018832:Molecular Chaperones; D009097:Multienzyme Complexes; D011809:Quinones; D011994:Recombinant Proteins; D011505:Protein-Tyrosine Kinases; C498978:MOK protein, human; D020928:Mitogen-Activated Protein Kinases; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex; D018833:Chaperonins; C001277:geldanamycin