A mechanism for tunable autoinhibition in the structure of a human Ca2+/calmodulin- dependent kinase II holoenzyme.
Cell
; 146(5): 732-45, 2011 Sep 02.
Article
en En
| MEDLINE
| ID: mdl-21884935
ABSTRACT
Calcium/calmodulin-dependent kinase II (CaMKII) forms a highly conserved dodecameric assembly that is sensitive to the frequency of calcium pulse trains. Neither the structure of the dodecameric assembly nor how it regulates CaMKII are known. We present the crystal structure of an autoinhibited full-length human CaMKII holoenzyme, revealing an unexpected compact arrangement of kinase domains docked against a central hub, with the calmodulin-binding sites completely inaccessible. We show that this compact docking is important for the autoinhibition of the kinase domains and for setting the calcium response of the holoenzyme. Comparison of CaMKII isoforms, which differ in the length of the linker between the kinase domain and the hub, demonstrates that these interactions can be strengthened or weakened by changes in linker length. This equilibrium between autoinhibited states provides a simple mechanism for tuning the calcium response without changes in either the hub or the kinase domains.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina
Límite:
Animals
/
Humans
Idioma:
En
Año:
2011
Tipo del documento:
Article