Entrez ID	Official symbol	Synonyms	Description	Location	Type of protein	External annotation
128866	CHMP4B	C20orf178, CHMP4A, CTPP3, CTRCT31, SNF7, SNF7-2, Shax1, VPS32B, Vps32-2, dJ553F4.4	charged multivesicular body protein 4B	20q11.22	protein-coding	Genecard

uniprot_summary

refseq_summary

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 (PubMed:12860994, PubMed:18209100). The ESCRT machinery also functions in topologically equivalent membrane fission events, such as the terminal stages of cytokinesis (PubMed:21310966). Together with SPAST, the ESCRT-III complex promotes nuclear envelope sealing and mitotic spindle disassembly during late anaphase (PubMed:26040712). Plays a role in the endosomal sorting pathway. ESCRT-III proteins are believed to mediate the necessary vesicle extrusion and/or membrane fission activities, possibly in conjunction with the AAA ATPase VPS4. When overexpressed, membrane-assembled circular arrays of CHMP4B filaments can promote or stabilize negative curvature and outward budding. CHMP4A/B/C are required for the exosomal release of SDCBP, CD63 and syndecan (PubMed:22660413).|(Microbial infection) The ESCRT machinery also functions in topologically equivalent membrane fission events, such as the budding of enveloped viruses (HIV-1 and other lentiviruses). Via its interaction with PDCD6IP involved in HIV-1 p6- and p9-dependent virus release.

This gene encodes 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. Mutations in this gene result in autosomal dominant posterior polar cataracts.

Caregory	Description	Value	Value range ( Low - High )	Comment
PLI	The probability of being loss-of-function (LoF) intolerant	0.882	[0, ..., 1]	Genes with high pLI scores (pLI ≥ 0.9) are extremely LoF intolerant, whereby genes with low pLI scores (pLI ≤ 0.1) are LoF tolerant. The score is calculated based on high-quality exome sequence data (ExAC) for 60,706 individuals of diverse ethnicities.
Haploinsufficiency (HI) score rank	Predicted probability of exhibiting haploinsufficiency		[100, ..., 1]	High ranks (e.g. 0-10%) indicate a gene is more likely to exhibit haploinsufficiency, low ranks (e.g. 90-100%) indicate a gene is more likely to NOT exhibit haploinsufficiency (DECIPHER, PMID: 20976243). haploinsufficiency means a single functional copy of a gene is insufficient to maintain its normal function and is extremely intolerant of LoF variation.
Gene brain expressed	Queried gene is expressed in brain tissues	True	[False, True]	The gene expression data are extracted from GTEx v7 and BrainSpan. A gene with the expression value of (log 2 based (TPM+1)) at least 1 TPM/RPKM/FPKM in one or more tissues related to the brain is considered brain-expressed.
Protein brain expressed	Queried protein is expressed in brain tissues	True	[False, True]	The protein expression data are extracted from ProteomicsDB (v2018.09). A protein with the expression value of (log based 10 (iBAQ intensity)) at least 0.5 in one or more tissues related to the brain is considered brain-expressed protein.
Carrying LoF DNMs	Number of loss-of-function DNMs hit the queried gene	0 (Case)	[0, ..., 67] with average of 0.160	Loss of function (LoF) mutations include frameshift indels, nonsense (stop-gained) and splice-site mutations, which can result in the gene product having less or no function and can have deleterious consequences.
		0 (Control)	[0, ..., 6] with average of 0.044
Carrying missense DNMs	Number of missense DNMs hit the queried gene	2 (Case)	[0, ..., 55] with average of 0.846	Missense mutations can result in changes in protein sequences, but are commonly considered to have less deleterious impacts than LoF mutations.
		0 (Control)	[0, ..., 21] with average of 0.300
FMRP binding targets	FMRP inteacting parters	False	[False, True]	FMRP loss of function causes Fragile X syndrome (FXS). The binding targets identified crosslinking immunoprecipitation (HITS-CLIP) in mouse brains (PMID:21784246). Many FMRP targets are among genes implicated in different neuropsychiatric diseases, such as autism, schizophrenia.
Postsynaptic density (PSD)	Protein associates with postsynaptic membranes of excitatory synapses	False	[False, True]	Abnormalities with PSD proteins are linked to various neuropsychiatric diseases including neurodevelopmental disorders.
Human essential genes	-	True	[False, True]	Genes are thought to be critical for human survival.