Video Experimental Relacionado
Updated: Apr 28, 2026
07:54
Purification of Tubulin with Controlled Posttranslational Modifications and Isotypes from Limited Sources by Polymerization-Depolymerization Cycles
Published on: November 5, 2020
4.6K
Base molecular para la acetilación de microtúbulos dependiente de la edad por la tubulina acetiltransferasa
Agnieszka Szyk1, Alexandra M Deaconescu2, Jeffrey Spector1
1Cell Biology and Biophysics Unit, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892, USA.
Cell
|June 7, 2014
Resumen
La tubulina acetiltransferasa (TAT) acetila los microtúbulos estables, marcándolos para las funciones celulares. Su velocidad catalítica, no la difusión, limita la acetilación, actuando como un reloj molecular para la vida útil de los microtúbulos.
Área de la Ciencia:
- La bioquímica es la bioquímica.
- Biología celular Biología celular.
- Biología Estructural Biología estructural.
Sus antecedentes:
- La acetilación de la α-tubulina Lys40 por la tubulina acetiltransferasa (TAT) es la única modificación posttranslacional conocida dentro del lumen de los microtúbulos.
- Esta modificación es crucial para identificar microtúbulos estables, esenciales para establecer la polaridad celular y la migración direccional.
Objetivo del estudio:
- Para aclarar la base mecanicista de la actividad TAT.
- Para entender la preferencia de TAT por los microtúbulos con bajas tasas de rotación.
Principales métodos:
- Las estructuras cocristalinas de alta resolución (1,35 Å) de TAT con análogos de bisubstrato.
- Pruebas bioquímicas utilizando diversos polímeros de tubulina. análisis bioquímicos utilizando diversos polímeros de tubulina. análisis bioquímicos utilizando diversos polímeros de tubulina. ensayos bioquímicos utilizando diversos polímeros de tubulina. ensayos bioquímicos utilizando diversos polímeros de tubulina. ensayos bioquímicos utilizando diversos polímeros de tubulina. ensayos bioquímicos utilizando diversos polímeros de tubulina. ensayos bioquímicos utilizando diversos polímeros de tubulina.
- Modelado de primeros principios y mediciones de una sola molécula.
Principales resultados:
- La acción de TAT se limita al lumen de los microtúbulos, con Lys40 en un sitio activo subóptimo.
- La actividad de los TAT se ve reforzada por los contactos de los interprotofilamentos dentro de los microtúbulos.
- La TAT escanea los microtúbulos bidireccionalmente y los acetilados estocásticamente, independientemente de los extremos de los microtúbulos.
- La actividad catalítica, más que la difusión luminal, es el paso que limita la velocidad de la acetilación.
Conclusiones:
- La TAT funciona como un "reloj lento" para las vidas de los microtúbulos debido a su preferencia por los microtúbulos sobre la tubulina libre y su modesta tasa catalítica.
- Los hallazgos proporcionan información mecanicista sobre la acetilación de microtúbulos y su papel en los procesos celulares.
Más Videos Relacionados
07:21Quantitative Microtubule Fractionation Technique to Separate Stable Microtubules, Labile Microtubules, and Free Tubulin in Mouse Tissues
Published on: November 17, 2023
3.0K
09:29Isolation of Intermediate Filament Proteins from Multiple Mouse Tissues to Study Aging-associated Post-translational Modifications
Published on: May 18, 2017
7.5K
Videos de Conceptos Relacionados
02:17Microtubule Instability
5.0K
Microtubules are hollow cylindrical filaments having a diameter of approximately 25 nm and a length that varies from 200 nm to 25 μm. GTP-bound tubulin subunits form αβ-heterodimers for microtubule assembly. These core building blocks interact longitudinally, polymerizing into protofilaments. The protofilaments then interact with one another through lateral bonding forces to form stable cylindrical microtubules. These cylindrical filaments are dynamic as they undergo repeated...
5.0K
01:32Assembly of Complex Microtubule Structures
2.1K
Complex microtubule structures are present in resting cells and in dividing cells. In resting cells, they are responsible for maintaining the cellular architecture, tracks for intracellular transport, positioning of organelles, assembly of cilia and flagella. They mediate the bipolar spindle assembly for chromosomal segregation and positioning of the cell division plate in dividing cells. The formation of microtubule complex structures depends on the cell type, cell stage, and cell function.
2.1K
01:45Destabilization of Microtubules
2.9K
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...
2.9K
01:23Microtubule Formation
6.3K
Microtubules are dynamic structures that undergo continuous assembly and disassembly. They originate from specialized multi-protein complexes known as microtubule organizing centers or MTOCs. Within the MTOC, the point of origin of the microtubule is known as the minus end, while the end radiating outward is the plus end. Microtubules serve two primary functions — the organization of spindle complexes to separate sister chromatids during mitotic or meiotic cell division and the formation...
6.3K
01:42Microtubule Associated Proteins (MAPs)
4.7K
Microtubule function and architecture are regulated by an array of specialized proteins called microtubule-associated proteins or MAPs. These proteins are widespread across different organisms and have conserved protein motifs, like the multi-TOG domain for tubulin binding found in the CLASP family of MAPs. Some MAPs are lineage-specific based on their conserved domains. Their functions depend upon the cytoskeletal architecture and cell type they are located within. In-plant cells, a specific...
4.7K
01:15Drugs that Stabilize Microtubules
2.2K
Microtubules are dynamic structures that undergo cycles of catastrophe and rescue. The microtubules play a central role in cell division by forming the spindle apparatus for segregating the chromosomes. This makes them ideal targets for regulating dividing cells in tumors and malignant cancer cells. Microtubule stabilizing drugs help stabilize the microtubule formation and promote its polymerization. Paclitaxel was the first microtubule stabilizing agent used as anticancer drug in chemotherapy...
2.2K