Phosphorylation of serine 13 is required for the proper function of the Hsp90 co-chaperone, Cdc37.
The Hsp90 co-chaperone Cdc37 provides an essential function for the biogenesis and support of numerous protein kinases. In this report, we demonstrate that mammalian Cdc37 is phosphorylated on Ser13 in situ in rabbit reticulocyte lysate and in cultured K562 cells and that casein kinase II is capable of quantitatively phosphorylating recombinant Cdc37 at this site. Mutation of Ser13 to either Ala or Glu compromises the recruitment of Cdc37 to Hsp90-kinase complexes but has only modest effects on its basal (client-free) binding to Hsp90. Furthermore, Cdc37 containing the complementing Ser to Glu mutation showed altered interactions with Hsp90-kinase complexes consistent with compromised Cdc37 modulation of the Hsp90 ATP-driven reaction cycle. Thus, the data indicate that phosphorylation of Cdc37 on Ser13 is critical for its ability to coordinate Hsp90 nucleotide-mediated conformational switching and kinase binding.
Shao
Jieya
J
Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, Oklahoma 74078-3035, USA.
Prince
Thomas
T
Hartson
Steven D
SD
Matts
Robert L
RL
D000255:Adenosine Triphosphate / Q000378:metabolism; D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D018797:Cell Cycle Proteins / Q000737:chemistry* / Q000378:metabolism; D018833:Chaperonins; D029721:Drosophila Proteins; D018698:Glutamic Acid / Q000737:chemistry; D018841:HSP90 Heat-Shock Proteins / Q000737:chemistry*; D006801:Humans; D020014:K562 Cells; D018832:Molecular Chaperones / Q000737:chemistry* / Q000378:metabolism; D008982:Molybdenum / Q000494:pharmacology; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D010766:Phosphorylation; D017354:Point Mutation; D011485:Protein Binding; D011487:Protein Conformation; D017510:Protein Folding; D017434:Protein Structure, Tertiary; D011817:Rabbits; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D012694:Serine / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
C498362:CDC37 protein, human; D018797:Cell Cycle Proteins; D029721:Drosophila Proteins; D018841:HSP90 Heat-Shock Proteins; D018832:Molecular Chaperones; D011994:Recombinant Proteins; C044659:molybdate; D018698:Glutamic Acid; D012694:Serine; D008982:Molybdenum; D000255:Adenosine Triphosphate; D000469:Alkaline Phosphatase; D018833:Chaperonins