Video Experimental Relacionado
Updated: Jun 27, 2026
08:02
Extracting Modified Microtubules from Mammalian Cells to Study Microtubule-Protein Complexes by Cryo-Electron Microscopy
Published on: March 3, 2023
Estructura y función del dominio de unión de microtúbulos de la dineína
Andrew P Carter1, Joan E Garbarino, Elizabeth M Wilson-Kubalek
1Howard Hughes Medical Institute and Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94158, USA.
Science (New York, N.Y.)
|December 17, 2008
Resumen
Dynein en los motores.
Área de la Ciencia:
- La función motora molecular tiene su función.
- Dinámica del citoesqueleto Dinámica del citoesqueleto
- Mecanismos de transporte de las células.
Sus antecedentes:
- Los motores de dineína son cruciales para el transporte intracelular y la motilidad celular.
- Una característica clave de la dineína es la separación de su dominio de unión de microtúbulos (MTBD, por sus siglas en inglés) de su dominio AAA+ ATPasa por medio de un tallo en espiral.
- Comprender la relación estructural y funcional entre estos dominios es esencial para elucidar el mecanismo de acción de la dineína.
Objetivo del estudio:
- Determinar la estructura cristalina del dominio de unión de microtúbulos (MTBD) de la dineína citoplasmática del ratón y la región en espiral-en espiral asociada.
- Investigar la base estructural para la comunicación entre el MTBD y el dominio AAA+ ATPasa.
- Para identificar el determinante primario de la motilidad direccional de la dineína.
Principales métodos:
- Se utilizó la cristalografía de rayos X para determinar la estructura de la MTBD de dynein y una parte de la bobina enrollada.
- El análisis estructural se centró en el tallo de la bobina enrollada y su papel potencial en la comunicación interdominio.
- Se realizaron ensayos funcionales para evaluar el papel del dominio MTBD y ATPasa en la determinación de la dirección de la motilidad.
Principales resultados:
- La estructura cristalina revela los detalles atómicos de la dynein MTBD y el tallo de la bobina enrollada.
- Se propone un cambio en el registro heptad de la bobina enrollada como mecanismo de comunicación entre la ATPasa y el MTBD.
- Los datos funcionales indican que el MTBD, en lugar del dominio ATPasa, es el principal determinante del movimiento direccional de la dineína.
Conclusiones:
- La estructura proporciona información sobre cómo se comunican el dominio ATPasa de dynein y el MTBD.
- El MTBD juega un papel sorprendentemente dominante en dictar la dirección de la motilidad impulsada por dynein.
- Este hallazgo desafía las suposiciones anteriores sobre los principales impulsores del movimiento direccional de la dineína.
Videos de Conceptos Relacionados
01:32Microtubule Associated Motor Proteins
Eukaryotic cells have different motor proteins for transporting various cargo within the cell. These motor proteins differ based on the filament they associate with, the direction they move within the cell, and the type of cargo they transport. Motor proteins that associate with microtubules are known as microtubule-associated motor proteins. There are two families of microtubule-associated motor proteins —Kinesins and Dyneins. Both these proteins assist in the transport of cellular cargos...
01:43The Movement of Organelles and Vesicles
In eukaryotic cells, cytoskeletal filaments such as actin, microtubules, and intermediate filaments form a mesh-like cytoskeletal network. These filaments serve as tracks for transporting cellular cargo. Specialized motor proteins use the chemical energy stored in adenosine triphosphate (ATP) for this transport. During interphase, microtubules are polarized, with the plus-end towards the cell periphery and the minus-end towards the cell center. Two microtubule-associated motor proteins,...
01:24Microtubules in Cell Motility
Microtubules are thick hollow cylindrical proteins that help form the cytoskeleton. Microtubules have varied roles in the cell. These filaments help form cellular appendages like cilia and flagella, which are responsible for locomotion. The cilia arise from basal bodies, separated from the main body by a membrane-like structure forming the transition zone. This zone is the gate for the entry of lipids and proteins, creating a unique composition of lipids and proteins in the ciliary membrane and...
01:24Microtubules in Cell Motility
Microtubules are thick hollow cylindrical proteins that help form the cytoskeleton. Microtubules have varied roles in the cell. These filaments help form cellular appendages like cilia and flagella, which are responsible for locomotion. The cilia arise from basal bodies, separated from the main body by a membrane-like structure forming the transition zone. This zone is the gate for the entry of lipids and proteins, creating a unique composition of lipids and proteins in the ciliary membrane and...
01:45Destabilization of Microtubules
The destabilization of microtubules can occur during different stages of the microtubule lifecycle, such as nucleation or elongation. It can take place at either end of the microtubule or in the microtubule lattices as a whole. The lifespan of individual microtubules within a cell varies according to the cell type and stage of the cell cycle. During interphase, the lifespan of the microtubule is about 30 minutes, while during cell division, it is about 15 minutes. In axonal microtubules of...
01:15Overview of Myosin Structure and Function
Myosins are a family of molecular motor proteins, first identified in the skeletal muscles, where they are responsible for muscle contraction. Along with their role in muscle contraction, these proteins also play a role in the intracellular transport of molecules and vesicles. There are twenty-four classes of myosins based on their domain sequence and organization. Of the twenty-four, six classes (Myosin I, Myosin II, Myosin V, Myosin VI, Myosin VII, and Myosin X) have been well characterized.