Identification and characterization of novel components of a Ca2+/calmodulin-dependent protein kinase cascade in HeLa cells.
FEBS Lett
; 550(1-3): 57-63, 2003 Aug 28.
Article
em En
| MEDLINE
| ID: mdl-12935886
ABSTRACT
In this report, we cloned a novel calmodulin-kinase (CaM-KIdelta) from HeLa cells and characterized its activation mechanism. CaM-KIdelta exhibits Ca(2+)/CaM-dependent activity that is enhanced (approximately 30-fold) in vitro by phosphorylation of its Thr180 by CaM-K kinase (CaM-KK)alpha, consistent with detection of CaM-KIdelta-activating activity in HeLa cells. We also identified a novel CaM-KKbeta isoform (CaM-KKbeta-3) in HeLa cells whose activity was highly Ca(2+)/CaM-independent. Transiently expressed CaM-KIdelta exhibited enhanced protein kinase activity in HeLa cells without ionomycin stimulation. This sustained activation of CaM-KIdelta was completely abolished by Thr180Ala mutation and inhibited by CaM-KK inhibitor, STO-609, indicating a functional CaM-KK/CaM-KIdelta cascade in HeLa cells.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Transdução de Sinais
/
Proteínas Quinases Dependentes de Cálcio-Calmodulina
Tipo de estudo:
Diagnostic_studies
Limite:
Animals
/
Humans
Idioma:
En
Ano de publicação:
2003
Tipo de documento:
Article