The carboxy-terminal domain of Grp94 binds to protein kinase CK2 alpha but not to CK2 holoenzyme.
Surface plasmon resonance analysis shows that the carboxy-terminal domain of Grp94 (Grp94-CT, residues 518-803) physically interacts with the catalytic subunit of protein kinase CK2 (CK2 alpha) under non-stressed conditions. A K(D) of 4 x 10(-7) was determined for this binding. Heparin competed with Grp94-CT for binding to CK2 alpha. CK2 beta also inhibited the binding of Grp94-CT to CK2 alpha, and CK2 holoenzyme reconstituted in vitro was unable to bind Grp94-CT. The use of CK2 alpha mutants made it possible to map the Grp94-CT binding site to the four lysine stretch (residues 74-77) present in helix C of CK2 alpha. Grp94-CT stimulated the activity of CK2 alpha wild-type but was ineffective on the CK2 alpha K74-77A mutant.
Roher
N
N
Department de Bioquímica i Biologia Molcular, Facultat de Ciències, Universitat Autònoma de Barcelona, Spain.
Sarno
S
S
Miró
F
F
Ruzzene
M
M
Llorens
F
F
Meggio
F
F
Itarte
E
E
Pinna
L A
LA
Plana
M
M
D000595:Amino Acid Sequence; D001665:Binding Sites; D047390:Casein Kinase II; D020134:Catalytic Domain; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008239:Lysine; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation; D010455:Peptides / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D021122:Protein Subunits; D013379:Substrate Specificity; D020349:Surface Plasmon Resonance
D018840:HSP70 Heat-Shock Proteins; D008565:Membrane Proteins; D010455:Peptides; D021122:Protein Subunits; C018551:glucose-regulated proteins; D047390:Casein Kinase II; D017346:Protein Serine-Threonine Kinases; D008239:Lysine