Charged multivesicular body protein 4b, Chromatin-modifying protein 4b, CHMP4b, SNF7 homolog associated with Alix 1, SNF7-2, hSnf7-2, Vacuolar protein sorting-associated protein 32-2, Vps32-2, hVps32-2, CHMP4B, C20orf178, SHAX1
CHMP4B is a member of the chromatin-modifying protein/charged multivesicular body protein (CHMP) protein family. The protein is part of the endosomal sorting complex required for transport (ESCRT) complex III (ESCRT-III), which functions in the sorting of endocytosed cell-surface receptors into multivesicular endosomes. The ESCRT machinery also functions in the final abscisson stage of cytokinesis and in the budding of enveloped viruses such as HIV-1. The three proteins of the CHMP4 subfamily interact with programmed cell death 6 interacting protein (PDCD6IP, also known as ALIX), which also functions in the ESCRT pathway. The CHMP4 proteins assemble into membrane-attached 5-nm filaments that form circular scaffolds and promote or stabilize outward budding. These polymers are proposed to help generate the luminal vesicles of multivesicular bodies.