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Preparation of Segmented Microtubules to Study Motions Driven by the Disassembling Microtubule Ends
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La fosforilación dependiente de calcio y calmodulina de una proteína de 62 kd induce la despolimerización de
1Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755.
Cell
|June 3, 1988
Resumen
Los aparatos mitóticos del erizo de mar (MA) contienen una proteína quinasa que fosforila un sustrato de 62 kd. Esta fosforilación desencadena la despolimerización de microtúbulos durante la mitosis, lo que tiene un impacto en la división celular.
Área de la Ciencia:
- Biología celular Biología celular.
- Biología Molecular Biología Molecular
- La bioquímica es la bioquímica.
Sus antecedentes:
- Los aparatos mitóticos (AM) son cruciales para la división celular.
- La fosforilación de proteínas juega un papel en la regulación de los procesos celulares.
- Los mecanismos específicos que controlan la estabilidad de la MA durante la mitosis no se comprenden completamente.
Objetivo del estudio:
- Para investigar el papel de una proteína quinasa dependiente de calcio y calmodulina en el erizo de mar MAs.
- Para determinar el efecto de la fosforilación de un sustrato específico de 62 kd en la estabilidad de MA.
- Explorar las implicaciones de estos hallazgos para los modelos de mitosis.
Principales métodos:
- Aislamiento de MAs de erizo de mar en un amortiguador estabilizador de microtúbulos.
- Ensayos de kinasa in vitro para estudiar la fosforilación de las proteínas.
- Estudios de etiquetado in vivo para confirmar la fosforilación del sustrato en células vivas.
- Microscopía para evaluar la despolimerización de los microtúbulos de MA.
Principales resultados:
- Se identificó una proteína quinasa dependiente de calcio y calmodulina en MAs. aislados.
- Esta quinasa fosforila un sustrato endógeno específico de 62 kd.
- La fosforilación de la proteína de 62 kd condujo a una despolimerización significativa de los microtúbulos de MA en 10 minutos.
- Las MAs sin 62 kd de fosforilación se mantuvieron estables durante hasta 30 minutos.
- Los estudios in vivo confirmaron la fosforilación de la proteína 62 kd durante la mitosis.
Conclusiones:
- La fosforilación específica de proteínas regula la estabilidad de la MA del erizo de mar.
- La fosforilación de la proteína 62 kd por una quinasa dependiente de calcio/calmodulina está relacionada con la despolimerización de los microtúbulos.
- Este proceso probablemente juega un papel en los eventos de la anafase durante la mitosis.
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