Detailed entry information

Protein Information (annotations from UniProt)

Database IDHIV0004258
UniProt IDQ9H444
Primary gene name(s)CHMP4B
Synonym gene name(s)C20orf178, SHAX1
Protein nameCharged multivesicular body protein 4b
Protein functionProbable 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. {ECO:0000269|PubMed:12860994, ECO:0000269|PubMed:18209100, ECO:0000269|PubMed:21310966, ECO:0000269|PubMed:22660413, ECO:0000269|PubMed:26040712}.; FUNCTION:, 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. {ECO:0000269|PubMed:14505569, ECO:0000269|PubMed:14505570, ECO:0000269|PubMed:14519844}.
Subcellular locationCytoplasm, cytosol {ECO:0000269|PubMed:15511219}. Late endosome membrane {ECO:0000269|PubMed:15511219, ECO:0000305|PubMed:12860994};
Peripheral membrane protein {ECO:0000305}. Midbody {ECO:0000269|PubMed:21310966}. Nucleus envelope {ECO:0000269|PubMed:26040712}. Note=Recruited to the nuclear envelope by CHMP7 during late anaphase, PubMed:26040712. {ECO:0000269|PubMed:26040712}.
ECO codeClick here for more information.
Amino acid sequence
FASTA format: Q9H444
Gene Ontology
(Biological Process)
Complete annatation
autophagy [GO:0006914];
cell separation after cytokinesis [GO:0000920];
endosomal transport [GO:0016197];
exit from mitosis [GO:0010458];
maintenance of lens transparency [GO:0036438];
membrane fission [GO:0090148];
mitotic cytokinesis [GO:0000281];
mitotic metaphase plate congression [GO:0007080];
multivesicular body assembly [GO:0036258];
negative regulation of autophagosome assembly [GO:1902902];
negative regulation of cell death [GO:0060548];
negative regulation of neuron death [GO:1901215];
nuclear envelope reassembly [GO:0031468];
nucleus organization [GO:0006997];
positive regulation of viral release from host cell [GO:1902188];
posttranslational protein targeting to membrane [GO:0006620];
protein homooligomerization [GO:0051260];
regulation of centrosome duplication [GO:0010824];
regulation of mitotic spindle assembly [GO:1901673];
regulation of viral process [GO:0050792];
ubiquitin-independent protein catabolic process via the multivesicular body sorting pathway [GO:0090611];
vacuolar transport [GO:0007034];
viral budding [GO:0046755];
viral budding via host ESCRT complex [GO:0039702];
viral life cycle [GO:0019058]
Gene Ontology
(Molecular Function)
Complete annatation
identical protein binding [GO:0042802];
protein homodimerization activity [GO:0042803]
Gene Ontology
(Cellular Component)
Complete annatation
cytoplasm [GO:0005737];
cytoplasmic side of plasma membrane [GO:0009898];
cytosol [GO:0005829];
endosome [GO:0005768];
ESCRT III complex [GO:0000815];
extracellular exosome [GO:0070062];
late endosome membrane [GO:0031902];
membrane coat [GO:0030117];
midbody [GO:0030496];
nuclear envelope [GO:0005635];
nucleus [GO:0005634]
Protein-protein interaction126170
Phylogenetic treeQ9H444
HIV replication factor status Zhou et al., Cell. Host. Microbe., 2008
Brass et al., Science, 2008
Smith et al., J. Immunol, 2010
gene status
Lu et al., J. Virol., 2011
      Folds changes 8h: unknown; Folds changes 16h: unknown; Tested: unknown;
Schoggins JW and Rice CM, Curr. Opin. Virol., 2011
      Targeted viruses: unknown
      Viral life cycle: unknown
      Mechanism related to antiviral activity: unknown
Anti-viral restriction factor Liu et al., Retrovirology, 2011
      unknown (Triplicates)

Gene Expression Profile       top

            Up-regulated;            Down-regulated

For brief introduction to each study, please go to the help page.

Gene expression during HIV latency

(1). Mohammadi et al., PLoS Pathog., 2014

Differentially expressed transcripts (Pairwise) during latency and subsequent viral reactivation using several agents - Primary CD4+ T-cell based model

DMSO: Dimethyl suloxyde (negative control) - 0.0033% final
SAHA: Vorinostat (Histone deacetylase inhibitor) - 0.5 μM
CD3: TCR Stimulation by IL-2+ antiCD3/anti-CD28 antibodies
IL7: Interleukin-7 based stimulation
DISU: Disulfiram (alcohol dehydrogenase inhibitor) - 0.5 μM
AZA: 5-azacytidine (AZA; DNA methylation inhibitor) - 1 μM
Experimental Condition Log2 Fold Change P value Adjusted P value
AZA vs. CD30.6978948397467710.03476634889918730.0735981961645645
AZA vs. DISU-0.1486276680695850.5566325370742050.948689448488927
AZA vs. IL7-0.07385737428468730.7008559666044360.999311006273513
AZA vs. SAHA0.04023103737783370.8689452781883070.969683233891807
DISU vs. CD3-0.8586503347410580.01918621574403490.0496332617342684
DISU vs. IL70.06543814084213020.7949488349413460.954423799099071
DISU vs. SAHA0.1906354955094620.5127473082542010.832081386657834
DMSO vs. AZA-0.08833139675521730.5981132058465051
DMSO vs. CD3-0.798478549809430.01354098957063680.0322419800666418
DMSO vs. DISU0.0582642715870330.8111499454890280.97885454093317
DMSO vs. IL70.02185203910177740.9032812357477460.979523619218739
DMSO vs. SAHA0.1228370815734360.6022217372083980.86531080507443
HIV vs. Mock in Activation0.1357242546683550.8273985121764030.999983755607037
HIV vs. Mock in Latency-0.05770123404857880.7272251275118990.999834320637052
IL7 vs. CD3-0.7649668966473290.01872046535614150.0496434859804927
SAHA vs. CD3-0.6817272148276370.05539243070829890.107808850674682
SAHA vs. IL70.1112097989712840.6479388422051870.827114488995082
(2). Iglesias-Ussel et al., J. Virol., 2013

Up and Downregulated transcripts during Latency (Latently infected CD4+ T cells vs Uninfected)- Primary CD4+Tcell based model
Log2 Fold Change P Value
unknown unknown

Gene expression during HIV infection and replication

(1). Imbeault et al., PloS Pathog., 2012

Transcriptomic profiling of HIV-1 infected CD4+ T cells - Primary CD4+ T cells
Experiment type Log2 Fold Change P Value Adjusted P Value
Infected vs. Mock unknown unknown unknown
Infected vs. Bystander unknown unknown unknown
(2). Lefebvre et al., J. Virol., 2011

Transcriptome analysis of T-cell line (Sup T1)
Log2 Fold Change unknown
(3). Li et al., J. Immunol., 2013

Lymphatic tissue
Acute Fold Change Acute P Value Asymt Fold Change Asypt P Value AIDS Fold Change AIDS P Value
unknown unknown unknown unknown unknown unknown
(4). Chang et al., MBio., 2011

Transcriptome analysis of T-cell line (Sup T1)

Derived from Sherrill-Mix et al., BMC Retrovirol., 2015 cross validation
Up-regulated (True) unknown
(5). Sherrill-Mix et al., BMC Retrovirol., 2015

Deep RNA-seq analysis of primary human T cell infected with low passage HIV isolate HIV89.6 - Primary CD4+ T cell based
Test Status Log2 Fold Change P Value
OK -0.103685 0.515736
(6). Rotger et al., PLoS Pathog., 2010

Genome-wide mRNA expression of CD4+ T cells from HIV-infected patient
(Genes differentially expressed (at adjusted p<0.01) according to the empirical Bayes approach)
Log2 Fold Change P Value
unknown unknown

Proteomic/Transcriptomics studies indicating differentially expressed genes mediated by HIV

(1). Greenwood et al., Elife, 2016

Activated (CD3/CD28) Primary human CD4+ T cells infected with pNL4-3-dE-EGFP. The table shows the complete (unfiltered) TMT (tandem mass tag)-based proteomic time course dataset
6 h 24 h 48 h 72 h RTi
0.985 0.946 0.951 0.97 0.938
(2). Navare et al., Virology, 2012

SUP-T1 cell line
FC-4hpi P-value FC-8hpi P-value FC-20hpi P-value Category
unknown unknown unknown unknown unknown unknown unknown
(3). Hyrcza et al., J. Virolo., 2007

Primary human CD4+ and CD8+ T Cells
Affymetrix Prob ID Fold Change In CD8? Category
unknown unknown unknown unknown

Protein Overview       top

Drug-protein Interaction       (annotations from DrugBank)      top

not found

Protein Secondary Structure       (annotations from PDB)      top

PDB Accession Method Resolution Chain Structure Preview
3C3Q X-ray 2.1Å B=207-224.
3UM3 X-ray 3.8Å B=121-224.
4ABM X-ray 1.8Å A/B/C/D=23-97.

HIV-1 Interaction       (annotations from NCBI HIV-1 Interaction Database)      top

HIV Partner Interaction Type PubMed
p6 interacts with 14505569
Pr55(Gag) recruits 25099357
p6 inhibited by 14505569
Pr55(Gag) co-localizes with 21394083
Pr55(Gag) regulated by 24107264
Pr55(Gag) interacts with 23027949

Metabolic/Signalling Pathway       (annotations from KEGG database)      top

Pathway Accession Number Description
hsa04144 Endocytosis - Homo sapiens (human)