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Los enlaces cruzados difusibles generan fuerzas dirigidas en redes de microtúbulos
Zdenek Lansky1, Marcus Braun1, Annemarie Lüdecke2
1B CUBE - Center for Molecular Bioengineering, Technische Universität Dresden, Arnoldstrasse 18, 01307 Dresden, Germany; Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany.
Cell
|March 10, 2015
Resumen
Los enlaces transversales difusibles de microtúbulos, como Ase1, pueden generar fuerzas de deslizamiento dirigidas cuando están confinados. Este hallazgo revela un nuevo mecanismo para la mecánica celular más allá de las proteínas motoras.
Área de la Ciencia:
- Biología celular Biología celular.
- La biofísica es la biofísica.
- Dinámica del citoesqueleto Dinámica del citoesqueleto
Sus antecedentes:
- La remodelación citoesquelética impulsa la división celular y la morfogénesis.
- Las fuerzas mecánicas se atribuyen principalmente a los motores moleculares y la dinámica de los filamentos.
- Se pensaba que los enlaces cruzados no enzimáticos solo generaban fricción.
Objetivo del estudio:
- Para investigar el papel mecánico de los enlaces cruzados de microtúbulos difusibles.
- Para determinar si los enlaces cruzados pueden generar fuerzas dirigidas.
- Comprender el mecanismo detrás de la generación de fuerza por los enlaces cruzados.
Principales métodos:
- Demostración experimental de la generación de fuerza por los enlaces cruzados de la familia Ase1/PRC1/Map65.
- Utilizando pinzas ópticas para medir directamente las fuerzas del rango piconewton.
- Análisis cuantitativo de la generación de fuerza basada en la expansión entrópica.
Principales resultados:
- Los enlaces cruzados difusibles de microtúbulos generan deslizamiento dirigido de microtúbulos cuando están confinados.
- Las fuerzas medidas antagonizan el deslizamiento de los microtúbulos impulsado por la proteína motora.
- La generación de fuerza se explica por la expansión entrópica de las moléculas de enlaces cruzados confinados.
Conclusiones:
- Los enlaces cruzados no enzimáticos pueden generar activamente trabajo mecánico.
- La mecánica celular aprovecha el movimiento térmico para la generación de fuerza dirigida.
- Las fuerzas entrópicas de las proteínas confinadas son significativas para la mecánica celular más allá de las redes citoesqueléticas.
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