{{.infobox .infobox-gene}}
| Symbol | MYO5B |
| Full Name | Myosin Vb |
| Chromosome | 18q21.1 |
| NCBI Gene ID | 4645 |
| OMIM | 614315 |
| Ensembl ID | ENSG00000170111 |
| UniProt ID | Q9ULL5 |
| Aliases | Myosin-5b, Myo5b |
| Associated Diseases | MVID, PD, neurological disorders |
MYO5B encodes myosin Vb, a member of the class V myosin family of motor proteins. Myosin Vb is a cytoskeletal motor that transports cargo along actin filaments, using ATP hydrolysis to generate mechanical force. It plays critical roles in intracellular transport, vesicle trafficking, organelle positioning, and synaptic function in neurons[@wool2013][@lewis2016].
Myosin Vb is expressed throughout the body, with particularly important functions in epithelial cells where it maintains apical-basal polarity, and in neurons where it participates in dendritic and axonal transport. Pathogenic mutations in MYO5B cause microvillus inclusion disease (MVID), a severe congenital enteropathy, while altered myosin Vb function has been implicated in neurodegenerative diseases including Parkinson's disease[@takagi2018][@tiwari2019].
MYO5B is a human gene. This page covers the gene's normal function, disease associations, expression patterns, and key research findings relevant to neurodegeneration.
The MYO5B gene is located on chromosome 18q21.1 and consists of 40 exons encoding a 1,843-amino acid protein. Myosin Vb is a dimeric motor protein with distinct structural domains[@reck-peterson2019]:
The motor domain binds to actin filaments, while the cargo-binding domain interacts with various organelles, vesicles, and mRNAs through adaptor proteins.
Myosin Vb functions as a processive motor[@krementsova2006]:
A single myosin Vb molecule can take hundreds of steps along an actin filament without detaching, making it highly processive.
Myosin Vb transports various cargoes[@brown2017][@sun2019]:
Vesicle transport:
Organelle positioning:
Myosin Vb interacts with specific cargo adaptors:
In epithelial cells, MYO5B is highly expressed and localizes to:
In neurons, MYO5B is expressed throughout the cell[@wool2013][@he2019]:
| Compartment | Function |
|---|---|
| Cell body | General transport |
| Dendrites | Dendritic vesicle transport |
| Dendritic spines | Synaptic vesicle delivery |
| Axon (lower) | Primarily myosin Va |
Specific neuronal populations:
Biallelic loss-of-function mutations in MYO5B cause microvillus inclusion disease (MVID)[@bridgham2019]:
Clinical features:
Pathogenesis:
Inheritance: Autosomal recessive
MYO5B dysfunction contributes to several neurodegenerative conditions[@tiwari2019]:
Myosin Vb contributes to axonal transport through[@wang2016]:
At synapses, myosin Vb plays crucial roles[@cao2014]:
Multiple mechanisms link myosin Vb to neurodegeneration:
MYO5B interacts with:
Targeting myosin Vb function:
Transport enhancers: Improve transport capacity in neurodegeneration
Motor protein stabilizers: Maintain motor function
Cargo adaptor modulators: Restore proper cargo binding
MYO5B as a biomarker:
In vitro approaches:
In vivo models:
Human studies: