Video Experimental Relacionado
Updated: Jul 6, 2026
06:45
In Vivo Single-Molecule Tracking at the Drosophila Presynaptic Motor Nerve Terminal
Published on: January 14, 2018
Munc13-1 es esencial para la competencia de fusión de las vesículas sinápticas glutamatérgicas
I Augustin1, C Rosenmund, T C Südhof
1Max-Planck-Institut für Experimentelle Medizin, AG Molekulare Neurobiologie, Göttingen, Bundesrepublik Deutschland.
Nature
|August 10, 1999
Resumen
Munc13-1 es crucial para la maduración de las vesículas sinápticas en las neuronas. Su ausencia detiene la liberación de neurotransmisores, pero algunas sinapsis y neuronas GABA no se ven afectadas, revelando diversas vías de maduración.
Área de la Ciencia:
- La neurociencia es la neurociencia.
- Biología Molecular Biología Molecular
- Biología celular Biología celular.
Sus antecedentes:
- La liberación de neurotransmisores se basa en la fusión de las vesículas sinápticas desencadenadas por el calcio.
- La maduración de la vesícula a un estado competente para la fusión es esencial antes de acoplarse a los sitios presinápticos.
Objetivo del estudio:
- Identificar las proteínas esenciales para la maduración de las vesículas sinápticas.
- Para investigar el papel de Munc13-1 en el ciclo de las vesículas sinápticas y la liberación de neurotransmisores.
Principales métodos:
- Utilizó ratones knockout Munc13-1 para estudiar las neuronas glutamatérgicas del hipocampo.
- Examinó la ultrastructura de la sinapsis y los mecanismos de liberación de neurotransmisores.
- Se investigó el efecto de la alfa-latrotoxina en la liberación en sinapsis deficientes de Munc13-1.
Principales resultados:
- Las neuronas deficientes de Munc13-1 forman sinapsis normales, pero exhiben una maduración vesicular detenida.
- La pérdida de Munc13-1 impide la liberación del potencial de acción, el ionóforo de calcio o el transmisor inducido por la sacarosa.
- La alfa-latrotoxina evita el requisito de Munc13-1, lo que indica una vía de liberación alternativa.
Conclusiones:
- Munc13-1 es esencial para la maduración de las vesículas sinápticas y la liberación de neurotransmisores.
- Existen múltiples vías de maduración de las vesículas sinápticas específicas del transmisor en las neuronas.
- Las neuronas GABAérgicas y un subconjunto de sinapsis glutamatérgicas utilizan procesos de maduración independientes de Munc13-1.
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...
01:33Coat Assembly and GTPases
Vesicles incorporate different coat protein subunits in different cell locations, which changes the properties of the coat, such as the shape and geometry of the transport vesicles. Thus, vesicle coat proteins also play a significant role in cargo selection.
Coat assembly depends on the local availability of phosphatidylinositol phosphates or PIPs and GTP-binding proteins. Adaptor proteins, which link the coat proteins to the membrane, bind to these PIPs and play a crucial role in controlling...
Coat assembly depends on the local availability of phosphatidylinositol phosphates or PIPs and GTP-binding proteins. Adaptor proteins, which link the coat proteins to the membrane, bind to these PIPs and play a crucial role in controlling...
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...
01:29Protein Folding Quality Check in the RER
ER is the primary site for the maturation and folding of soluble and transmembrane secretory proteins. The calnexin cycle is a specific chaperone system that folds and assesses the confirmation of N-glycosylated proteins before they can exit the ER lumen. The primary players of this quality check pipeline are the lectins, ER-resident chaperones, and a glucosyl transferase enzyme. In case the calnexin system in the lumen fails to salvage a misfolded protein, it is transported to the cytoplasm...
01:10Integrins
Animal and protozoan cells do not have cell walls to help maintain shape and provide structural stability. Instead, these eukaryotic cells secrete a sticky mass of carbohydrates and proteins into the spaces between adjacent cells. This network of proteins and molecules is called an extracellular matrix or ECM.
Some ECM proteins assemble into a basement membrane to which the remaining components adhere. Proteoglycans typically form the bulk of the ECM while fibrous proteins, like collagen,...
Some ECM proteins assemble into a basement membrane to which the remaining components adhere. Proteoglycans typically form the bulk of the ECM while fibrous proteins, like collagen,...
01:15Activation of Integrins
Integrins bind ligands and transmit information from outside the cell to inside or vice-versa through an "outside-in signaling" or "inside-out signaling."
In "outside-in signaling," external factors in the extracellular space bind to exposed ligand binding sites on integrins. This causes the inactive protein to undergo a conformational change to become active. Integrins are often clustered on the cell membrane. Repetitive and regularly spaced ligand binding events provide an effective stimulus.
In "outside-in signaling," external factors in the extracellular space bind to exposed ligand binding sites on integrins. This causes the inactive protein to undergo a conformational change to become active. Integrins are often clustered on the cell membrane. Repetitive and regularly spaced ligand binding events provide an effective stimulus.