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Regulación del ciclo celular de la miosina-V por la proteína quinasa II dependiente del calcio y la calmodulina
R L Karcher1, J T Roland, F Zappacosta
1Department of Cell and Structural Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
Science (New York, N.Y.)
|August 18, 2001
Resumen
La fosforilación de la miosina-V durante la mitosis libera proteínas motoras de los orgánulos. Este proceso regulado por la proteína quinasa II dependiente de calcio/calmodulina (CaMKII) tiene un impacto en el transporte de orgánulos.
Área de la Ciencia:
- Biología celular Biología celular.
- Los motores moleculares son los motores moleculares de las moléculas.
- La fosforilación de las proteínas.
Sus antecedentes:
- Los motores de miosina-V facilitan el transporte de los orgánulos.
- La mitosis conduce a una regulación a la baja del transporte de orgánulos de miosina-V.
- La fosforilación de la miosina-V es la hipótesis para mediar esta regulación descendente.
Objetivo del estudio:
- Para investigar el mecanismo de regulación descendente de la miosina-V durante la mitosis.
- Para identificar el sitio específico de fosforilación en la miosina-V.
- Para determinar la quinasa responsable de la fosforilación de la miosina-V.
Principales métodos:
- Se utilizó el mapeo de fosfopéptidos por espectrometría de masas.
- Se realizaron experimentos con extracto de huevo de Xenopus mitótico.
- Se emplearon inhibidores de la proteína quinasa II (CaMKII) dependientes del calcio y la calmodulina.
Principales resultados:
- Un solo residuo de serina en el dominio de unión a los orgánulos de la cola de miosina-V fue fosforilado.
- Esta fosforilación causó la liberación de miosina-V de los orgánulos.
- El sitio de fosforilación coincidía con la secuencia de consenso de CaMKII.
- La inhibición de CaMKII impidió la liberación de miosina-V.
Conclusiones:
- La fosforilación mitótica de la miosina-V por CaMKII regula la unión de los orgánulos.
- Esta liberación de carga dependiente de la fosforilación es un mecanismo clave que controla el transporte de orgánulos de miosina-V durante la mitosis.
- Este mecanismo puede ser ampliamente aplicable a la función de la miosina-V.
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