The autophosphorylation and p34cdc2 phosphorylation sites of casein kinase-2 beta-subunit are not essential for reconstituting the fully-active heterotetrameric holoenzyme.
Biochim Biophys Acta
; 1164(2): 223-5, 1993 Jul 10.
Article
em En
| MEDLINE
| ID: mdl-8329453
ABSTRACT
Two mutants of human casein kinase-2 beta-subunit with short deletions at either their amino (delta 1-4) or carboxy (delta 209-215) terminal side have been created that have lost the capability to undergo autophosphorylation and p34cdc2 mediated phosphorylation, respectively. Both mutants give rise to reconstituted CK2 holoenzymes displaying basal catalytic activity, thermostability and responsiveness to polylysine, identical to those of wild-type holoenzyme, whose reconstitution, moreover, is not affected by previous phosphorylation of the beta-subunit at either its N-terminal or C-terminal sites. Unlike the wild-type beta and beta(delta 209-215), however, beta(delta 1-4) fails to confer to the reconstituted holoenzyme the typical responsiveness to NaCl stimulation. These results suggest that while neither the autophosphorylation nor the p34cdc2 phosphorylation sites are required for conferring a stable structure and full catalytic activity to CK2, the autophosphorylation site is implicated in the NaCl-dependent fine tuning of CK2 activity.
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Base de dados:
MEDLINE
Assunto principal:
Proteínas Quinases
/
Proteína Quinase CDC2
Idioma:
En
Revista:
Biochim Biophys Acta
Ano de publicação:
1993
Tipo de documento:
Article
País de afiliação:
Itália