UNC45B Gene
Unc-45 Myosin Chaperone B
Gene Information Card
| Symbol | UNC45B |
|---|---|
| Full Name | Unc-45 Myosin Chaperone B |
| Gene Type | Protein coding |
| Chromosomal Location | 17q12 |
| NCBI Gene ID | 146862 ncbi.nlm.nih.gov/gene/146862 |
| Ensembl ID | ENSG00000141510 |
| UniProt ID | Q8IWX7 |
| OMIM ID | 611220 |
| HGNC ID | 30591 |
| Aliases | UNC-45B, SMUNC45B, CMYA4 |
Description
UNC45B encodes a member of the UNC45 family of myosin chaperones. The protein is essential for myosin folding and assembly, particularly in striated muscle. It interacts with Hsp90 and Hsp70 to facilitate proper myosin incorporation into thick filaments. Mutations in UNC45B are associated with congenital myopathy and cardiomyopathy.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Congenital myopathy | Impaired myosin folding due to UNC45B loss-of-function mutations leads to muscle fiber disorganization | ClinVar, OMIM |
| Dilated cardiomyopathy | Defective chaperone activity disrupts sarcomere integrity in cardiac muscle | ClinVar, OMIM |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Heart | 12.5 | High |
| Skeletal muscle | 8.3 | Medium |
| Brain | 0.8 | Low |
| Liver | 0.5 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| H9c2 (rat cardiomyoblasts) | 5.2 | Model for cardiac expression |
| C2C12 (mouse myoblasts) | 6.1 | Model for skeletal muscle expression |
| HEK293 | 0.3 | Low endogenous expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.782C>T (p.Pro261Leu) | Missense | Rare | Reduced chaperone activity |
| c.1123G>A (p.Gly375Arg) | Missense | Rare | Impaired Hsp90 binding |
| c.1456_1457del (p.Leu486fs) | Frameshift | Very rare | Loss of function |
Mutation functional classification
Loss of Function (LOF)
Frameshift and nonsense mutations that truncate the protein or disrupt the UCS domain lead to loss of chaperone activity.
Gain of Function (GOF)
No gain-of-function mutations reported.
Dominant Negative (DN)
Missense mutations in the central domain may exert dominant-negative effects by sequestering Hsp90.
View complete mutation data：
Gene Ontology (GO)
| • unfolded protein binding (GO:0051082) | • chaperone binding (GO:0051087) |
| • myosin filament assembly (GO:0030239) | • regulation of the force of heart contraction (GO:0002026) |
| • cytoplasm (GO:0005737) |
Pathways
• Chaperone-mediated protein folding (Hsp90/Hsp70)
• Myosin assembly and sarcomere organization
Protein Summary
UNC45B is a 961-amino acid protein containing an N-terminal tetratricopeptide repeat (TPR) domain for Hsp90/Hsp70 interaction, a central domain, and a C-terminal UCS (UNC-45/CRO1/SHE4) domain that binds myosin. It acts as a co-chaperone to ensure proper myosin head folding and thick filament assembly in muscle cells.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| UNC45B Knockout HEK293 Cell Line | EDJ-KQ10509 | Human | 146862 | Details Get a Quote |
| UNC45B Knockout HeLa Cell Line | EDJ-KQ58565 | Human | 146862 | Details Get a Quote |
| UNC45B Knockout A-549 Cell Line | EDJ-KQ67054 | Human | 146862 | Details Get a Quote |
| UNC45B Knockout HCT 116 Cell Line | EDJ-KQ75455 | Human | 146862 | Details Get a Quote |
