Crystal structure of the Ca²âº/calmodulin-dependent protein kinase kinase in complex with the inhibitor STO-609.
J Biol Chem
; 286(25): 22570-9, 2011 Jun 24.
Article
em En
| MEDLINE
| ID: mdl-21504895
ABSTRACT
Ca(2+)/calmodulin (CaM)-dependent protein kinase (CaMK) kinase (CaMKK) is a member of the CaMK cascade that mediates the response to intracellular Ca(2+) elevation. CaMKK phosphorylates and activates CaMKI and CaMKIV, which directly activate transcription factors. In this study, we determined the 2.4 Å crystal structure of the catalytic kinase domain of the human CaMKKß isoform complexed with its selective inhibitor, STO-609. The structure revealed that CaMKKß lacks the αD helix and that the equivalent region displays a hydrophobic molecular surface, which may reflect its unique substrate recognition and autoinhibition. Although CaMKKß lacks the activation loop phosphorylation site, the activation loop is folded in an active-state conformation, which is stabilized by a number of interactions between amino acid residues conserved among the CaMKK isoforms. An in vitro analysis of the kinase activity confirmed the intrinsic activity of the CaMKKß kinase domain. Structure and sequence analyses of the STO-609-binding site revealed amino acid replacements that may affect the inhibitor binding. Indeed, mutagenesis demonstrated that the CaMKKß residue Pro(274), which replaces the conserved acidic residue of other protein kinases, is an important determinant for the selective inhibition by STO-609. Therefore, the present structure provides a molecular basis for clarifying the known biochemical properties of CaMKKß and for designing novel inhibitors targeting CaMKKß and the related protein kinases.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Benzimidazóis
/
Inibidores de Proteínas Quinases
/
Naftalimidas
/
Quinase da Proteína Quinase Dependente de Cálcio-Calmodulina
Tipo de estudo:
Prognostic_studies
Limite:
Humans
Idioma:
En
Ano de publicação:
2011
Tipo de documento:
Article