The in vitro phosphorylation of the co-chaperone mSTI1 by cell cycle kinases substantiates a predicted casein kinase II-p34cdc2-NLS (CcN) motif.
The co-chaperone murine stress-inducible protein 1 (mSTI1), a Hsp70/Hsp90 organizing protein (Hop) homolog, functions as a physical link between Hsp70 and Hsp90 by mediating the formation of the mSTI1/ Hsp70/Hsp90 chaperone heterocomplex. We show here that mSTI1 is an in vitro substrate of cell cycle kinases. Casein kinase II (CKII) phosphorylates mSTI1 at S189, and cdc2 kinase (p34cdc2) at T198, substantiating a predicted CKII-p34cdc2-NLS (CcN) motif. The possible implications of this phosphorylation as a cell cycle checkpoint are discussed.
Longshaw
V M
VM
Department of Molecular and Cell Biology, University of the Witwatersrand, South Africa.
Dirr
H W
HW
Blatch
G L
GL
Lässle
M
M
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D016203:CDC2 Protein Kinase / Q000378:metabolism*; D047390:Casein Kinase II; D002453:Cell Cycle; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism*; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism*; D006360:Heat-Shock Proteins / Q000378:metabolism*; D051379:Mice; D018832:Molecular Chaperones / Q000378:metabolism; D008969:Molecular Sequence Data; D019913:Nuclear Localization Signals / Q000378:metabolism*; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism
D018840:HSP70 Heat-Shock Proteins; D018841:HSP90 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D018832:Molecular Chaperones; D019913:Nuclear Localization Signals; D010750:Phosphoproteins; D011993:Recombinant Fusion Proteins; C489791:Stip1 protein, mouse; D047390:Casein Kinase II; D017346:Protein Serine-Threonine Kinases; D016203:CDC2 Protein Kinase