Function
Charged multivesicular body protein (CHMP)s are part of Endosomal Sorting Complex Required for Transport (ESCRT) together with the Vacuolar protein sorting-associated proteins that performs the topologically unique membrane bending and scission reaction away from the cytoplasm. This process is required for the multivesicular body (MVP) pathway, cytokinesis and HIV budding. There are five distinct ESCRT complexes (0,I,II,III,Vps4) with distinct functions[1]. CHMPs are part of the ESCRT-III complex.
- CHMP1A and CHMP1B are required for bodies containing plastid material during autophagy into the cytoplasm [2].
- CHMP2B polymerization scaffolds membranes as part of outward membrane deformation[3].
- CHMP3 sorts transmembrane proteins into lysosomes/vacuoles via the multivesicular body pathway. .
- CHMP4B circular filament arrays can promote or stabilize negative membrane curvature and outward budding.
- CHMP5 has possibly a regulatory role on apoptosis-associated genes.
Disease
Mutations in CHMP2B are implicated in ALS[4].
Structural highlights
The ampiphatic CHMP5 creates a hydrophobic binding collar that includes which make . A is formed between CHMP5 negative surface which includes 13 Asp and Glu residues and 11 basic residues on the vacuolar protein sorting-associated protein Vta1 homolog binding surface[5].
3D structures of charged multivesicular body protein
Charged multivesicular body protein 3D structures
