Site-directed mutants of the beta subunit of protein kinase CK2 demonstrate the important role of Pro-58.
The following amino acids of the Xenopus laevis beta subunit of protein kinase CK2 (casein kinase 2) were changed to alanine: Pro-58 (beta P-->A); Asp-59 and Glu-60 and Glu-61 (beta DEE-->AAA); His-151-153 (beta HHH-->AAA). The last 37 amino acids of the carboxyl end were deleted (beta delta 179-215). Stimulation of CK2 alpha catalytic subunit activity was measured with casein as substrate and the following relative activities were observed: beta P-->A > beta DEE-->AAA >>> beta WT > beta HHH-->AAA >>> beta delta 179-215. The beta DEE-->AAA and beta P-->A were similar to beta WT in reducing CD2 alpha binding to DNA but beta delta 179-215 was less active. The results indicate that both Pro-58 and the surrounding acidic cluster play roles in dampening the activation of CK2 alpha and that the carboxyl end of beta is involved in the interaction with CK2 alpha.
Hinrichs
M V
MV
Departamento de Bioquímica, Facultad de Medicina, Universidad de Chile, Santiago.
Gatica
M
M
Allende
C C
CC
Allende
J E
JE
D000818:Animals; D001483:Base Sequence; D047390:Casein Kinase II; D002364:Caseins / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009154:Mutation / Q000502:physiology*; D010766:Phosphorylation; D011392:Proline / Q000502:physiology*; D011487:Protein Conformation; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014982:Xenopus laevis
D002364:Caseins; D004268:DNA-Binding Proteins; D004247:DNA; D011392:Proline; D047390:Casein Kinase II; D017346:Protein Serine-Threonine Kinases