Chromatin Modifying Protein 2b (CHMP2B) Human Recombinant Protein

This gene encodes a component of the heteromeric ESCRT-III complex (Endosomal Sorting Complex Required for Transport III) that functions in the recycling or degradation of cell surface receptors. ESCRT-III functions in the concentration and invagination of ubiquitinated endosomal cargos into intralumenal vesicles. The protein encoded by this gene is found as a monomer in the cytosol or as an oligomer in ESCRT-III complexes on endosomal membranes. It is expressed in neurons of all major regions of the brain. Mutations in this gene result in one form of familial frontotemporal lobar degeneration. [provided by RefSeq, Jul 2008]

CHMP2B: Probable core component of the endosomal sorting required for transport complex III (ESCRT-III) which is involved in multivesicular bodies (MVBs) formation and sorting of endosomal cargo proteins into MVBs. MVBs contain intraluminal vesicles (ILVs) that are generated by invagination and scission from the limiting membrane of the endosome and mostly are delivered to lysosomes enabling 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 from the invaginating membrane before the ILV is released. The ESCRT machinery also functions in topologically equivalent membrane fission events, such as the terminal stages of cytokinesis and the budding of enveloped viruses (HIV-1 and other lentiviruses). ESCRT-III proteins are believed to mediate the necessary vesicle extrusion and/or membrane fission activities, possibly in conjunction with the AAA ATPase VPS4. Defects in CHMP2B are the cause of frontotemporal dementia, chromosome 3-linked (FTD3). FTD3 is characterized by an onset of dementia in the late 50's initially characterized by behavioral and personality changes including apathy, restlessness, disinhibition and hyperorality, progressing to stereotyped behaviors, non-fluent aphasia, mutism and dystonia, with a marked lack of insight. The brains of individuals with FTD3 have no distinctive neuropathological features. They show global cortical and central atrophy, but no beta-amyloid deposits. Defects in CHMP2B are the cause of amyotrophic lateral sclerosis type 17 (ALS17). An adult-onset progressive neurodegenerative disorder with predominantly lower motor neuron involvement, manifest as muscle weakness and wasting of the upper and lower limbs, bulbar signs, and respiratory insufficiency. Belongs to the SNF7 family.

Chromosomal Location of Human Ortholog: 3p11.2

Cellular Component: nucleoplasm; mitochondrion; late endosome membrane; lysosome; late endosome; cytoplasm; plasma membrane; intracellular; nucleus; cytosol; endosome

Molecular Function: protein domain specific binding; protein binding

Biological Process: protein transport; endosome organization and biogenesis; viral reproduction; cell separation during cytokinesis; vacuolar transport; viral infectious cycle; cognition; endosome transport; mitotic metaphase plate congression; nuclear organization and biogenesis

Disease: Frontotemporal Dementia, Chromosome 3-linked; Amyotrophic Lateral Sclerosis 17