Cdc37 interacts with the glycine-rich loop of Hsp90 client kinases.
Recently, we identified a client-binding site of Cdc37 that is required for its association with protein kinases. Phage display technology and liquid chromatography-tandem mass spectrometry (which identifies a total of 33 proteins) consistently identify a unique sequence, GXFG, as a Cdc37-interacting motif that occurs in the canonical glycine-rich loop (GXGXXG) of protein kinases, regardless of their dependence on Hsp90 or Cdc37. The glycine-rich motif of Raf-1 (GSGSFG) is necessary for its association with Cdc37; nevertheless, the N lobe of Raf-1 (which includes the GSGSFG motif) on its own cannot interact with Cdc37. Chimeric mutants of Cdk2 and Cdk4, which differ sharply in their affinities toward Cdc37, show that their C-terminal portions may determine this difference. In addition, a nonclient kinase, the catalytic subunit of cyclic AMP-dependent protein kinase, interacts with Cdc37 but only when a threonine residue in the activation segment of its C lobe is unphosphorylated. Thus, although a region in the C termini of protein kinases may be crucial for accomplishing and maintaining their interaction with Cdc37, we conclude that the N-terminal glycine-rich loop of protein kinases is essential for physically associating with Cdc37.
Terasawa
Kazuya
K
Department of Biophysics and Biochemistry, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 133-0033, Japan.
Yoshimatsu
Katsuhiko
K
Iemura
Shun-Ichiro
S
Natsume
Tohru
T
Tanaka
Keiji
K
Minami
Yasufumi
Y
D020816:Amino Acid Motifs / Q000235:genetics; D000595:Amino Acid Sequence; D000818:Animals; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D018833:Chaperonins / Q000235:genetics / Q000378:metabolism*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D051357:Cyclin-Dependent Kinase 2 / Q000378:metabolism; D051358:Cyclin-Dependent Kinase 4 / Q000378:metabolism; D005998:Glycine / Q000235:genetics / Q000378:metabolism*; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D010766:Phosphorylation; D025941:Protein Interaction Mapping; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D019908:Proto-Oncogene Proteins c-raf / Q000378:metabolism; D013912:Threonine / Q000235:genetics / Q000378:metabolism
C498362:CDC37 protein, human; D018797:Cell Cycle Proteins; D018841:HSP90 Heat-Shock Proteins; D013912:Threonine; D017346:Protein Serine-Threonine Kinases; D019908:Proto-Oncogene Proteins c-raf; D017868:Cyclic AMP-Dependent Protein Kinases; D051357:Cyclin-Dependent Kinase 2; D051358:Cyclin-Dependent Kinase 4; D018833:Chaperonins; D005998:Glycine