SPG20

SPART
Available structures PDB Human UniProt search: PDBe RCSB List of PDB id codes 2DL1, 4U7I
Identifiers
Aliases	SPART, SPARTIN, TAHCCP1, SPG20, spastic paraplegia 20 (Troyer syndrome)
External IDs	OMIM: 607111 HomoloGene: 32243 GeneCards: SPART
Gene location (Human) Chr. Chromosome 13 (human) Band 13q13.3 Start 36,301,638 bp End 36,370,180 bp
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in Achilles tendon canal of the cervix left uterine tube popliteal artery stromal cell of endometrium left adrenal gland gastric mucosa gallbladder corpus callosum tibial nerve n/a More reference expression data BioGPS More reference expression data
Gene ontology Molecular function protein binding ubiquitin protein ligase binding Cellular component mitochondrial outer membrane lipid droplet plasma membrane synapse cytoplasm midbody cytosol Biological process cell division regulation of mitochondrial membrane potential negative regulation of collateral sprouting in absence of injury adipose tissue development neuromuscular process abscission lipid droplet organization negative regulation of BMP signaling pathway Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 23111 n/a Ensembl ENSG00000133104 n/a UniProt Q8N0X7 n/a RefSeq (mRNA) NM_001142294 NM_001142295 NM_001142296 NM_015087 n/a RefSeq (protein) NP_001135766 NP_001135767 NP_001135768 NP_055902 NP_001135766.1 NP_001135767.1 NP_001135768.1 NP_055902.1 n/a Location (UCSC) Chr 13: 36.3 – 36.37 Mb n/a PubMed search n/a
Wikidata
View/Edit Human

Spartin is a protein that in humans is encoded by the SPG20 gene.

This gene encodes a protein that contains a MIT (Microtubule Interacting and Trafficking molecule) domain. This protein may be involved in endosomal trafficking, microtubule dynamics, or both functions. Spartin loss has been associated to mitochondrial dysfunction, impaired complex I activity and altered pyruvate metabolism. Frameshift mutations associated with this gene cause autosomal recessive spastic paraplegia 20 (Troyer syndrome). Troyer syndrome (SPG20) is a complicated type of hereditary spastic paraplegias (HSPs). HSP is a category of neurological disorder characterized by spasticity and muscle weakness in the lower limbs.

Background

The original description of this gene mutation and associated symptoms were described in 1967. This mutation is commonly found in high frequency with the Amish population. Newer studies have found that the mutation is not isolated to the Amish population, but also resides in the Omani population.

Presentation

This syndrome is not only characterized by spasticity and weakness in the lower limbs, but also with dysarthria, mental retardation or mild developmental delay, and muscle wasting or muscle atrophy.

Physical

Individuals appear to have difficulty walking, and report a clumsy, spastic gait which worsens over time. Some additional common physical features include overgrowth of the jaw bone, hammer toes, hand and feet abnormalities, and pes cavus.

Cognitive

Cognitive challenges, including developmental delay and difficulty with performance in school, may affect individuals with this syndrome.

Neurologic

Neurologic examination of individuals with this mutation may show dysmetria in the upper extremities, hyperreflexia, distal amyotrophy and ankle clonus, in addition to spasticity, weakness and dysarthria.

Diagnostic Imaging

The cerebellar vermis may present with mild atrophy and a loss of white matter volume.

Through Lifespan

Facial dysmorphism and subtle skeletal features are common in younger children. The condition progressively worsens, as spasticity and distal amyotrophy symptoms are revealed more in teenage years. SPG20 expression in the adult is relatively modest, however it is widespread in the nervous system. Longitudinal comparison of magnetic resonance imaging concluded that there was a progression of the syndrome; thus, the condition appears to worsen over time.

External links

• GeneReviews/NCBI/NIH/UW entry on Troyer Syndrome **

Further reading

• Hillier LD, Lennon G, Becker M, et al. (1997). "Generation and analysis of 280,000 human expressed sequence tags". Genome Res. 6 (9): 807–28. doi:10.1101/gr.6.9.807. PMID 8889549.
• Nagase T, Ishikawa K, Miyajima N, et al. (1998). "Prediction of the coding sequences of unidentified human genes. IX. The complete sequences of 100 new cDNA clones from brain which can code for large proteins in vitro". DNA Res. 5 (1): 31–9. doi:10.1093/dnares/5.1.31. PMID 9628581.
• Auer-Grumbach M, Fazekas F, Radner H, et al. (1999). "Troyer syndrome: a combination of central brain abnormality and motor neuron disease?". J. Neurol. 246 (7): 556–61. doi:10.1007/s004150050403. PMID 10463356. S2CID 22666392.
• Strausberg RL, Feingold EA, Grouse LH, et al. (2003). "Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences". Proc. Natl. Acad. Sci. U.S.A. 99 (26): 16899–903. Bibcode:2002PNAS...9916899M. doi:10.1073/pnas.242603899. PMC 139241. PMID 12477932.
• Ciccarelli FD, Proukakis C, Patel H, et al. (2003). "The identification of a conserved domain in both spartin and spastin, mutated in hereditary spastic paraplegia". Genomics. 81 (4): 437–41. doi:10.1016/S0888-7543(03)00011-9. PMID 12676568.
• Ota T, Suzuki Y, Nishikawa T, et al. (2004). "Complete sequencing and characterization of 21,243 full-length human cDNAs". Nat. Genet. 36 (1): 40–5. doi:10.1038/ng1285. PMID 14702039.
• Dunham A, Matthews LH, Burton J, et al. (2004). "The DNA sequence and analysis of human chromosome 13". Nature. 428 (6982): 522–8. Bibcode:2004Natur.428..522D. doi:10.1038/nature02379. PMC 2665288. PMID 15057823.
• Liu M, Liu Y, Cheng J, et al. (2004). "Transactivating effect of hepatitis C virus core protein: a suppression subtractive hybridization study". World J. Gastroenterol. 10 (12): 1746–9. doi:10.3748/wjg.v10.i12.1746. PMC 4572261. PMID 15188498.
• Colland F, Jacq X, Trouplin V, et al. (2004). "Functional proteomics mapping of a human signaling pathway". Genome Res. 14 (7): 1324–32. doi:10.1101/gr.2334104. PMC 442148. PMID 15231748.
• Gerhard DS, Wagner L, Feingold EA, et al. (2004). "The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC)". Genome Res. 14 (10B): 2121–7. doi:10.1101/gr.2596504. PMC 528928. PMID 15489334.
• Bakowska JC, Jenkins R, Pendleton J, Blackstone C (2005). "The Troyer syndrome (SPG20) protein spartin interacts with Eps15". Biochem. Biophys. Res. Commun. 334 (4): 1042–8. doi:10.1016/j.bbrc.2005.06.201. PMID 16036216.
• Lu J, Rashid F, Byrne PC (2006). "The hereditary spastic paraplegia protein spartin localises to mitochondria". J. Neurochem. 98 (6): 1908–19. doi:10.1111/j.1471-4159.2006.04008.x. PMID 16945107.
• Bakowska JC, Jupille H, Fatheddin P, et al. (2007). "Troyer syndrome protein spartin is mono-ubiquitinated and functions in EGF receptor trafficking". Mol. Biol. Cell. 18 (5): 1683–92. doi:10.1091/mbc.E06-09-0833. PMC 1855030. PMID 17332501.
• Bakowska, J.C.; Jenkins, R.; Pendleton, J.; Blackstone, C. (2005). "The Troyer syndrome (SPG20) protein interacts with Eps15". Biochemical and Biophysical Research Communications. 334 (4): 1042–1048. doi:10.1016/j.bbrc.2005.06.201. PMID 16036216.
• Manzini, M. C.; Rajab, A.; Maynard, T. M.; Mochida, G. H.; Tan, W.; Nasir, R.; et al. (2010). "Developmental and degenerative features in a complicated spastic paraplegic". Annals of Neurology. 67 (4): 516–525. doi:10.1002/ana.21923. PMC 3027847. PMID 20437587.
• Ciccarelli, F. D.; Patton, M. A.; McKusick, V. A.; Crosby, A. H. (2002). "SPG20 is mutated in Troyer syndrome, an hereditary spastic paraplegia". Nature Genetics. 31 (4): 347–348. doi:10.1038/ng937. PMID 12134148. S2CID 23051225.