RESUMEN

The sorting of transmembrane proteins (e.g., cell surface receptors) into the multivesicular body (MVB) pathway to the lysosomal/vacuolar lumen requires the function of the ESCRT protein complexes. The soluble coiled-coil-containing proteins Vps2, Vps20, Vps24, and Snf7 are recruited from the cytoplasm to endosomal membranes where they oligomerize into a protein complex, ESCRT-III. ESCRT-III contains two functionally distinct subcomplexes. The Vps20-Snf7 subcomplex binds to the endosomal membrane, in part via the myristoyl group of Vps20. The Vps2-Vps24 subcomplex binds to the Vps20-Snf7 complex and thereby serves to recruit additional cofactors to this site of protein sorting. We provide evidence for a role for ESCRT-III in sorting and/or concentration of MVB cargoes.

Asunto(s)

Proteínas Portadoras/metabolismo , Compartimento Celular/fisiología , Membrana Celular/metabolismo , Endosomas/metabolismo , Células Eucariotas/metabolismo , Proteínas Fúngicas/metabolismo , Proteínas Nucleares , Transporte de Proteínas/fisiología , Proteínas de Saccharomyces cerevisiae , Vesículas Transportadoras/metabolismo , Animales , Proteínas Portadoras/ultraestructura , Membrana Celular/ultraestructura , Complejos de Clasificación Endosomal Requeridos para el Transporte , Endosomas/ultraestructura , Escherichia coli , Células Eucariotas/ultraestructura , Proteínas Fúngicas/ultraestructura , Lisosomas/metabolismo , Lisosomas/ultraestructura , Sustancias Macromoleculares , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Microscopía Electrónica , Mutación/fisiología , Péptido Hidrolasas/metabolismo , Saccharomyces cerevisiae , Vesículas Transportadoras/ultraestructura , Red trans-Golgi/metabolismo , Red trans-Golgi/ultraestructura