Video Experimental Relacionado

Updated: Jun 15, 2025

In Vitro Polymerization of F-actin on Early Endosomes

In Vitro Polymerization of F-actin on Early Endosomes

Published on: August 28, 2017

El andamio de la submembrana de la actina-espectrina restringe la endocitosis a lo largo de los axones proximales

Florian Wernert¹, Satish Babu Moparthi², Florence Pelletier¹

¹Aix Marseille Université, CNRS, INP UMR7051, NeuroCyto, 13005 Marseille, France.

Science (New York, N.Y.)

|August 22, 2024

Resumen

La endocitosis mediada por clatrina ocurre en el segmento inicial del axón (AIS) a través de hoyos estables recubiertos de clatrina. La actina y la dinámica del espectro regulan estos hoyos, controlando la internalización de proteínas de la membrana a lo largo del eje del axón.

Área de la Ciencia:

La neurociencia
Biología celular
La bioquímica

Sus antecedentes:

La endocitosis mediada por clatrina es crucial para la función neuronal, pero se entiende mal a lo largo del eje del axón.
El segmento inicial del axón (AIS) tiene un andamio de actina-espectrina único que recubre su membrana plasmática.

Objetivo del estudio:

Investigar las estructuras cubiertas de clatrina y la endocitosis en el AIS.
Para determinar el papel del andamio de la actina-espectrina en la endocitosis axonal.

Principales métodos:

Microscopía de alta resolución
Microscopía electrónica con réplica de platino
Imágenes de células vivas de neuronas cultivadas

Principales resultados:

Las fosas recubiertas de clatrina se forman en "limpiezas" libres de actina en el AIS.
La desorganización del andamio de actina-espectrina mejora la formación de hoyos recubiertos de clatrina.
Las fosas recubiertas de clatrina de AIS son inusualmente estables y su internalización se desencadena mediante la estimulación neuronal a través de la polimerización de actina.

Conclusiones:

La espectrina y la actina son reguladores clave de la formación y escisión de hoyos recubiertos de clatrina en el AIS.
Este mecanismo controla la internalización de proteínas de la membrana a lo largo del eje del axón.

Más Videos Relacionados

Labeling F-actin Barbed Ends with Rhodamine-actin in Permeabilized Neuronal Growth Cones

Labeling F-actin Barbed Ends with Rhodamine-actin in Permeabilized Neuronal Growth Cones

Published on: March 17, 2011

Expanding the Toolkit for In Vivo Imaging of Axonal Transport

Expanding the Toolkit for In Vivo Imaging of Axonal Transport

Published on: December 23, 2021

Videos de Conceptos Relacionados

Cell Motility through Blebbing

Cell Motility through Blebbing

Blebs are a type of membrane protrusion formed by the internal hydrostatic pressure of the cytoplasm. Blebs are observed in several cell types, including fibroblasts, immune cells, and single-celled organisms like the amoeba. The primary function of blebs is cell locomotion and apoptosis, but they are also found during necrosis and cell division. The life cycle of a bleb comprises an initiation phase followed by the expansion and retraction phases.
Blebbing Through the Matrix
In multicellular...

Mechanism of Filopodia Formation

Mechanism of Filopodia Formation

Filopodia are thin, actin-rich cellular protrusions that play an important role in many fundamental cellular functions. They vary in their occurrence, length, and positioning in different cell types, suggesting their diverse roles.
Their main function is to guide migrating cells during normal tissue morphogenesis or cancer metastasis by recognizing and making initial contacts with the extracellular matrix. However, they can also act as stationary cell anchors or help to establish communication...

Assembly of Complex Microtubule Structures

Assembly of Complex Microtubule Structures

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.

Tail-anchoring of Proteins in the ER Membrane

Tail-anchoring of Proteins in the ER Membrane

Tail-anchored, or TA, proteins are estimated to make up to 3-5% of membrane proteins found in the eukaryotic cell. Such proteins have a single transmembrane domain located approximately 30 amino acid residues upstream from the C-terminal end. As a result, the signal recognition particle (SRP) cannot guide a TA protein to the ER membrane for cotranslational insertion. Hence, they are integrated into the ER membrane post-translationally using their C-terminal end as the anchor. TA proteins...

Mechanism of Lamellipodia Formation

Mechanism of Lamellipodia Formation

Cells migrating in response to external stimuli form lamellipodia, which are thin membrane protrusions supported by a mesh of linked, branched, or unbranched actin filaments. These actin filaments interact with myosin motor proteins, creating the dynamic actomyosin complex within the cytoskeleton. Contractility, or the ability to generate contractile stress, is inherent to the actomyosin complex. It helps cells detect the stiffness of the surrounding ECM and exert contractile force for...

The Contractile Ring

The Contractile Ring

Contractile rings are composed of microfilaments and are responsible for separating the daughter cells during cytokinesis. Contractile ring assembly proceeds along with other cell cycle events; however, very few mechanistic details are known about the timing and coordination of the contractile rings with the cell cycle.
A small GTPase, RhoA, controls the function and assembly of the contractile ring. RhoA belongs to the Ras superfamily of proteins. The activation of formins by RhoA promotes...