Video Experimental Relacionado
Updated: Jun 27, 2026
08:53
Using Scaffold Liposomes to Reconstitute Lipid-proximal Protein-protein Interactions In Vitro
Published on: January 11, 2017
El ciclo de GTPasa de la dinamina está acoplado al apretamiento y liberación de la membrana, lo que lleva a la fisión
Pavel V Bashkirov1, Sergey A Akimov, Alexey I Evseev
1Program on Physical Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), Bethesda, MD 20892-1855, USA.
Cell
|December 17, 2008
Resumen
La proteína dinamina utiliza la energía GTP para remodelar las membranas celulares mediante la formación y desmontaje de andamios, impulsando la fisión de la membrana a través del estrés de la curvatura lipídica. Este proceso permite una remodelación eficiente de la membrana sin fugas.
Área de la Ciencia:
- Biología celular Biología celular.
- La bioquímica es la bioquímica.
- Dinámica de las membranas Dinámica de las membranas.
Sus antecedentes:
- La dinamina es una GTPasa esencial para la fisión de la membrana en la endocitosis.
- El mecanismo por el cual la dinamina utiliza la hidrólisis de GTP para la remodelación de la membrana sigue siendo incompletamente entendido.
Objetivo del estudio:
- Para aclarar cómo la dinamina aprovecha la energía de hidrólisis GTP para la remodelación de la membrana y la fisión.
- Para investigar el papel de la formación del andamio de dinamina y la curvatura de los nanotubos de lípidos en la fisión de la membrana.
Principales métodos:
- Monitoreo de la permeabilidad iónica de los nanotubos lipídicos (NT) para evaluar el efecto de la dinamina en la estructura de la membrana.
- Utilizando la composición de nanotubos de lípidos para estudiar el apretamiento y la fisión de la membrana inducida por dinamina.
- Analizando los ciclos de montaje y desmontaje dependientes de la GTPasa de los andamios de dinamina.
Principales resultados:
- La dinamina exprimió los nanotubos de lípidos a radios muy pequeños, dependiendo de la composición de los lípidos.
- La fisión de la membrana fue mediada por ciclos dependientes de la GTPasa de montaje/desmontaje de andamios de dinamina cortos, no andamios largos.
- La fisión se produjo espontáneamente al soltarse el andamio, sin fugas, impulsada por el estrés de curvatura y la inclinación cooperativa de lípidos (hemifission).
Conclusiones:
- La dinamina transmite energía GTP para crear andamios periódicos de curvatura limitada que desestabilizan las bicapas lipídicas.
- Este mecanismo facilita la remodelación de la membrana y la fisión a través de la hemifisión, asegurando la integridad de la membrana.
- La naturaleza estocástica de la fisión está relacionada con el estrés de curvatura y las propiedades de los lípidos.
Más Videos Relacionados
10:19Single-Molecule FRET Imaging for Observing the Conformational Dynamics of Dynamin-Like GTPase Atlastin
Published on: January 24, 2025
10:58SNARE-mediated Fusion of Single Proteoliposomes with Tethered Supported Bilayers in a Microfluidic Flow Cell Monitored by Polarized TIRF Microscopy
Published on: August 24, 2016
Videos de Conceptos Relacionados
01:32Pinching-off of Coated Vesicles
Vesicle budding is orchestrated by distinct cytosolic proteins such as adaptor proteins, coat proteins, and GTPases. To initiate vesicle budding, membrane-bending proteins containing crescent-shaped BAR domains bind to the lipid heads in the bilayer and distort the membrane to form a protein-coated vesicle bud. Adaptors proteins such as AP2 for clathrin-coated vesicles can nucleate on the deformed membrane. Finally, coat proteins such as clathrin or COPI and COPII assemble into a coat forming...
01:43SNAREs and Membrane Fusion
Once a transport vesicle has recognized its target organelle, the vesicular membrane needs to fuse with the target membrane to unload the cargo. Transmembrane proteins called SNAREs present on organelle membranes and their vesicles, mediate vesicle fusion.
SNAREs exist in pairs that symmetrically interact and catalyze the fusion of the lipid bilayers in vesicle and target organelle. v-SNARE in the vesicle membrane are single polypeptide chains that bind to a complementary t-SNARE, composed of 2...
SNAREs exist in pairs that symmetrically interact and catalyze the fusion of the lipid bilayers in vesicle and target organelle. v-SNARE in the vesicle membrane are single polypeptide chains that bind to a complementary t-SNARE, composed of 2...
01:25Rab Cascades
Rab GTPases act in a regulated cascade during membrane fusion, helping the lipid bilayers mix. The Rab family of proteins are active when bound to GTP, and inactive when bound to GDP. Hence, they act as guanine nucleotide-dependent molecular switches. Rab-GTP recognizes and binds to long or short-range tethering proteins to capture the target vesicle. These tethers coordinate with SNAREs on the vesicle and the target membrane to assemble the trans SNARE complex that locks the mixing bilayers.
02:14GTPases and their Regulation
Guanine nucleotide-binding proteins (G-proteins), also known as GTPases, are a superfamily of proteins that regulate many cellular processes, such as cell signaling, vesicular transport, and the regulation of cell shape and motility. Mutation or dysfunction of these proteins can lead to disease. There are around 40,000 known G-proteins that can broadly be classified into two groups ‒ small G-proteins consisting of a single domain and large multi-domain G-proteins.
Large G-proteins, also known...
Large G-proteins, also known...
02:14GTPases and their Regulation
Guanine nucleotide-binding proteins (G-proteins), also known as GTPases, are a superfamily of proteins that regulate many cellular processes, such as cell signaling, vesicular transport, and the regulation of cell shape and motility. Mutation or dysfunction of these proteins can lead to disease. There are around 40,000 known G-proteins that can broadly be classified into two groups ‒ small G-proteins consisting of a single domain and large multi-domain G-proteins.
Large G-proteins, also known...
Large G-proteins, also known...
01:19Actin Filament Depolymerization
Actin filaments (F-actin) are composed of actin subunits. The dissociation of actin monomers can occur from either end of F-actin. The rate of dissociation is faster from the minus-end or the pointed end, where the actin subunits exist with a bound ADP, together known as ADP-actin. The depolymerization of F-actin is aided by proteins, including the actin-depolymerizing factor (ADF) and cofilin family of proteins, gelsolin, and glia maturation factor (GMF).
In F-actin, the ADF/cofilin proteins...
In F-actin, the ADF/cofilin proteins...