Charged multivesicular body protein 1b-1 (Chmp1b1)

Probable peripherally associated component of the endosomal sorting required for transport complex III (ESCRT-III) that is involved in multivesicular bodies (MVBs) formation and sorting of endosomal cargo proteins into MVBs. MVBs include intraluminal vesicles (ILVs) that are generated by invagination and scission in the limiting membrane of the endosome and mostly are delivered to lysosomes allowing degradation of membrane proteins, such as stimulated growth factor receptors, lysosomal enzymes and lipids.

The MVB pathway appears to require the sequential function of ESCRT-O, -I,-II and -III complexes. ESCRT- III proteins mostly dissociate in the invaginating membrane until the ILV is discharged.