CHMP4B
Charged Multivesicular Body Protein 4B: A Key Regulator of ESCRT-III Complex and Vesicular Trafficking
Gene Information Card
| Symbol | CHMP4B |
|---|---|
| Full Name | Charged Multivesicular Body Protein 4B |
| Gene Type | Protein coding |
| Chromosomal Location | 20q11.22 |
| NCBI Gene ID | 128866 ncbi.nlm.nih.gov/gene/128866 |
| Ensembl ID | ENSG00000101421 |
| UniProt ID | Q9H444 |
| OMIM ID | 610897 |
| HGNC ID | 16171 |
| Aliases | CHMP4, C20orf178, SNF7-2, VPS32B |
Description
CHMP4B encodes a core component of the endosomal sorting complex required for transport III (ESCRT-III), which is essential for multivesicular body (MVB) biogenesis, cytokinesis, and viral budding. The protein localizes to the midbody during cell division and is involved in membrane fission and scission events. Mutations in CHMP4B are associated with autosomal dominant posterior polar cataract and may contribute to other neurodegenerative and developmental disorders.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Posterior polar cataract 2 (CTRCT2) | Dominant-negative mutations impair ESCRT-III function, disrupting lens fiber cell membrane remodeling and leading to cataract formation. | OMIM #610897; ClinVar; NCBI |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | 12.5 | Medium |
| Eye | 15.2 | Medium |
| Heart | 8.3 | Low |
| Liver | 6.1 | Low |
| Kidney | 9.7 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HeLa | 14.0 | Moderate expression |
| HEK293 | 11.5 | Moderate expression |
| SH-SY5Y | 13.2 | Moderate expression |
| HepG2 | 7.8 | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.481G>A (p.Asp161Asn) | Missense | Rare | Dominant-negative; associated with posterior polar cataract |
| c.497G>A (p.Arg166His) | Missense | Rare | Dominant-negative; associated with posterior polar cataract |
| c.503G>A (p.Arg168His) | Missense | Rare | Dominant-negative; associated with posterior polar cataract |
Mutation functional classification
Loss of Function (LOF)
Not well characterized; complete loss may be lethal or cause severe developmental defects.
Gain of Function (GOF)
Not reported.
Dominant Negative (DN)
Mutations in CHMP4B (e.g., Asp161Asn, Arg166His, Arg168His) act as dominant-negative alleles, disrupting ESCRT-III complex assembly and function, leading to cataract.
View complete mutation data：
Gene Ontology (GO)
Pathways
• ESCRT-III complex pathway (Reactome: R-HSA-917729)
• Endosomal sorting complex required for transport (ESCRT) (KEGG: hsa04144)
Protein Summary
CHMP4B is a 224-amino acid protein that forms part of the ESCRT-III complex. It is involved in membrane remodeling and scission events required for MVB formation, cytokinesis, and viral budding. The protein contains a basic N-terminal region and a coiled-coil domain that mediates interactions with other ESCRT-III components. Mutations in CHMP4B disrupt its ability to polymerize and function properly, leading to cellular trafficking defects and disease.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| No Data | ||||
