SPART (Spartin) encodes a protein involved in lipid droplet metabolism and mitochondrial function. Mutations in SPART cause autosomal recessive hereditary spastic paraplegia (SPG20).
SPART (Spartin) encodes a protein involved in lipid droplet metabolism, mitochondrial function, and endosomal trafficking. Mutations in SPART cause autosomal recessive hereditary spastic paraplegia (SPG20), also known as Troyer syndrome. The protein is widely expressed and localizes to lipid droplets, mitochondria, and the cytoskeleton.
| Attribute |
Value |
| Symbol |
SPART |
| Full Name |
Spartin |
| Chromosomal Location |
4p16.3 |
| NCBI Gene ID |
55037 |
| OMIM |
607111 |
| Ensembl ID |
ENSG00000133104 |
| UniProt ID |
Q9UQ10 |
| Associated Diseases |
Hereditary Spastic Paraplegia (SPG20), Troyer Syndrome |
Spartin is a multifunctional protein involved in several cellular processes:
- Lipid Droplet Metabolism: SPART localizes to lipid droplets and regulates their turnover and distribution
- Mitochondrial Function: Involved in mitochondrial dynamics and quality control
- Endosomal Trafficking: Participates in endosomal sorting and membrane trafficking
- Cytoskeletal Organization: Associates with microtubules and affects cell morphology
- E3 Ubiquitin Ligase Activity: Contains a SPARTin-like domain with potential ubiquitination functions
The protein contains multiple domains including an N-terminal microtubule-interacting domain and a C-terminal lipid droplet-binding domain.
- Troyer Syndrome: Caused by frameshift mutations in SPART
- Autosomal recessive inheritance pattern
- Characterized by spastic paraplegia, developmental delay, and short stature
- Additional features include dysarthria, behavioral problems, and distal muscle atrophy
- Neuropathology shows degeneration of corticospinal tracts
- Loss of spartin function leads to impaired lipid droplet turnover
- Mitochondrial dysfunction in neurons
- Disrupted endosomal trafficking
- Accumulation of lipids in various tissues
SPART shows broad expression:
- Brain: High expression in cerebral cortex, cerebellum, and spinal cord
- Motor Neurons: Detectable in corticospinal motor neurons
- Peripheral Tissues: Expressed in muscle, liver, and other tissues
- Subcellular Localization: Cytoplasmic, associated with lipid droplets and mitochondria
- Soderblom et al., SPART mutations cause Troyer syndrome (2005)
- Lonardo et al., Spartin functions in lipid droplet turnover (2010)
- Ishmael et al., Analysis of spartin in neurodegeneration (2006)