Atrophin-1 is a protein that in humans is encoded by the ATN1 gene.[1] The encoded protein includes a serine repeat and a region of alternating acidic and basic amino acids, as well as the variable glutamine repeat.[2] The function of Atrophin-1 has not yet been determined.[3] There is evidence provided by studies of Atrophin-1 in animals to suggest it acts as a transcriptional co-repressor.[3] Atrophin-1 can be found in the nuclear and cytoplasmic compartments of neurons.[3] It is expressed in nervous tissue.[4]
The function of Atrophin-1 has not been defined yet. It is widely hypothesized that Atrophin-1 functions as a transcriptional co-repressor.[5] A transcriptional co-repressor is a protein that indirectly suppresses the activity of specific genes by interacting with DNA-binding proteins.[5]
Clinical significance
The ATN1 gene has a segment of DNA called the CAG trinucleotide repeat.[5] It is made up of cytosine, adenine, and guanine.[5] The number of CAG repeats in the ATN1 gene in a healthy person will range from six to thirty-five repeats.[5] CAG repeats that exceed thirty-five can cause a gain-of-function mutation in ATN1.[6] Studies have supported the idea that mutated Atrophin-1 gathers in neurons and disrupts cell function.[7] The sequence of the ATN1 gene contains a nuclear localizing signal (NLS) and a nuclear export signal (NES).[7] It has been shown that a mutation of the NES in ATN1 can change where ATN1 localizes, and can cause aggregation to occur in the nucleus.[7] This can lead to an increase in cellular toxicity.[7]
Mutations in ATN1 are associated with a form of trinucleotide repeat disorder known as "dentatorubral-pallidoluysian atrophy" or "dentatorubropallidoluysian atrophy". Dentatorubral-pallidoluysian atrophy (DRPLA) is a rare neurodegenerative disorder characterized by cerebellar ataxia, myoclonic epilepsy, choreoathetosis, and dementia.[1] The disorder is related to the expansion of a trinucleotide repeat within this gene.[1]In patients with DRPLA, truncated ATN1 has been observed forming intranuclear aggregates that cause cell death.[7] The symptoms of this disorder can be credited to the significant reduction of brain and spinal tissue observed in those afflicted with DRPLA.[8] There are both juvenile-onset and late adult-onset variants of DRPLA, which show differing degrees of severity of specific symptoms.[8]
↑Shen Y, Peterson AS (February 2009). "Atrophins' emerging roles in development and neurodegenerative disease". Cellular and Molecular Life Sciences. 66 (3): 437–46. doi:10.1007/s00018-008-8403-9. PMID18953689.
↑Shen Y, Lee G, Choe Y, Zoltewicz JS, Peterson AS (February 2007). "Functional architecture of atrophins". The Journal of Biological Chemistry. 282 (7): 5037–44. doi:10.1074/jbc.M610274200. PMID17150957.
↑Okamura-Oho Y, Miyashita T, Ohmi K, Yamada M (June 1999). "Dentatorubral-pallidoluysian atrophy protein interacts through a proline-rich region near polyglutamine with the SH3 domain of an insulin receptor tyrosine kinase substrate". Human Molecular Genetics. 8 (6): 947–57. doi:10.1093/hmg/8.6.947. PMID10332026.
↑ 10.010.110.2Wood JD, Yuan J, Margolis RL, Colomer V, Duan K, Kushi J, Kaminsky Z, Kleiderlein JJ, Sharp AH, Ross CA (June 1998). "Atrophin-1, the DRPLA gene product, interacts with two families of WW domain-containing proteins". Molecular and Cellular Neurosciences. 11 (3): 149–60. doi:10.1006/mcne.1998.0677. PMID9647693.
↑Yanagisawa H, Bundo M, Miyashita T, Okamura-Oho Y, Tadokoro K, Tokunaga K, Yamada M (May 2000). "Protein binding of a DRPLA family through arginine-glutamic acid dipeptide repeats is enhanced by extended polyglutamine". Human Molecular Genetics. 9 (9): 1433–42. doi:10.1093/hmg/9.9.1433. PMID10814707.
Yazawa I, Nukina N, Hashida H, Goto J, Yamada M, Kanazawa I (May 1995). "Abnormal gene product identified in hereditary dentatorubral-pallidoluysian atrophy (DRPLA) brain". Nature Genetics. 10 (1): 99–103. doi:10.1038/ng0595-99. PMID7647802.
Nagafuchi S, Yanagisawa H, Ohsaki E, Shirayama T, Tadokoro K, Inoue T, Yamada M (October 1994). "Structure and expression of the gene responsible for the triplet repeat disorder, dentatorubral and pallidoluysian atrophy (DRPLA)". Nature Genetics. 8 (2): 177–82. doi:10.1038/ng1094-177. PMID7842016.
Burke JR, Wingfield MS, Lewis KE, Roses AD, Lee JE, Hulette C, Pericak-Vance MA, Vance JM (August 1994). "The Haw River syndrome: dentatorubropallidoluysian atrophy (DRPLA) in an African-American family". Nature Genetics. 7 (4): 521–4. doi:10.1038/ng0894-521. PMID7951323.
Nagafuchi S, Yanagisawa H, Sato K, Shirayama T, Ohsaki E, Bundo M, Takeda T, Tadokoro K, Kondo I, Murayama N (January 1994). "Dentatorubral and pallidoluysian atrophy expansion of an unstable CAG trinucleotide on chromosome 12p". Nature Genetics. 6 (1): 14–8. doi:10.1038/ng0194-14. PMID8136826.
Koide R, Ikeuchi T, Onodera O, Tanaka H, Igarashi S, Endo K, Takahashi H, Kondo R, Ishikawa A, Hayashi T (January 1994). "Unstable expansion of CAG repeat in hereditary dentatorubral-pallidoluysian atrophy (DRPLA)". Nature Genetics. 6 (1): 9–13. doi:10.1038/ng0194-9. PMID8136840.
Li SH, McInnis MG, Margolis RL, Antonarakis SE, Ross CA (June 1993). "Novel triplet repeat containing genes in human brain: cloning, expression, and length polymorphisms". Genomics. 16 (3): 572–9. doi:10.1006/geno.1993.1232. PMID8325628.
Ansari-Lari MA, Muzny DM, Lu J, Lu F, Lilley CE, Spanos S, Malley T, Gibbs RA (April 1996). "A gene-rich cluster between the CD4 and triosephosphate isomerase genes at human chromosome 12p13". Genome Research. 6 (4): 314–26. doi:10.1101/gr.6.4.314. PMID8723724.
Takano T, Yamanouchi Y, Nagafuchi S, Yamada M (February 1996). "Assignment of the dentatorubral and pallidoluysian atrophy (DRPLA) gene to 12p 13.31 by fluorescence in situ hybridization". Genomics. 32 (1): 171–2. doi:10.1006/geno.1996.0100. PMID8786114.
Yanagisawa H, Fujii K, Nagafuchi S, Nakahori Y, Nakagome Y, Akane A, Nakamura M, Sano A, Komure O, Kondo I, Jin DK, Sørensen SA, Potter NT, Young SR, Nakamura K, Nukina N, Nagao Y, Tadokoro K, Okuyama T, Miyashita T, Inoue T, Kanazawa I, Yamada M (March 1996). "A unique origin and multistep process for the generation of expanded DRPLA triplet repeats". Human Molecular Genetics. 5 (3): 373–9. doi:10.1093/hmg/5.3.373. PMID8852663.
Margolis RL, Li SH, Young WS, Wagster MV, Stine OC, Kidwai AS, Ashworth RG, Ross CA (March 1996). "DRPLA gene (atrophin-1) sequence and mRNA expression in human brain". Brain Research. Molecular Brain Research. 36 (2): 219–26. doi:10.1016/0169-328X(95)00241-J. PMID8965642.
Ansari-Lari MA, Shen Y, Muzny DM, Lee W, Gibbs RA (March 1997). "Large-scale sequencing in human chromosome 12p13: experimental and computational gene structure determination". Genome Research. 7 (3): 268–80. doi:10.1101/gr.7.3.268. PMID9074930.
Miyashita T, Okamura-Oho Y, Mito Y, Nagafuchi S, Yamada M (November 1997). "Dentatorubral pallidoluysian atrophy (DRPLA) protein is cleaved by caspase-3 during apoptosis". The Journal of Biological Chemistry. 272 (46): 29238–42. doi:10.1074/jbc.272.46.29238. PMID9361003.
Wellington CL, Ellerby LM, Hackam AS, Margolis RL, Trifiro MA, Singaraja R, McCutcheon K, Salvesen GS, Propp SS, Bromm M, Rowland KJ, Zhang T, Rasper D, Roy S, Thornberry N, Pinsky L, Kakizuka A, Ross CA, Nicholson DW, Bredesen DE, Hayden MR (April 1998). "Caspase cleavage of gene products associated with triplet expansion disorders generates truncated fragments containing the polyglutamine tract". The Journal of Biological Chemistry. 273 (15): 9158–67. doi:10.1074/jbc.273.15.9158. PMID9535906.
Wood JD, Yuan J, Margolis RL, Colomer V, Duan K, Kushi J, Kaminsky Z, Kleiderlein JJ, Sharp AH, Ross CA (June 1998). "Atrophin-1, the DRPLA gene product, interacts with two families of WW domain-containing proteins". Molecular and Cellular Neurosciences. 11 (3): 149–60. doi:10.1006/mcne.1998.0677. PMID9647693.
Hayashi Y, Kakita A, Yamada M, Koide R, Igarashi S, Takano H, Ikeuchi T, Wakabayashi K, Egawa S, Tsuji S, Takahashi H (December 1998). "Hereditary dentatorubral-pallidoluysian atrophy: detection of widespread ubiquitinated neuronal and glial intranuclear inclusions in the brain". Acta Neuropathologica. 96 (6): 547–52. doi:10.1007/s004010050933. PMID9845282.
Takiyama Y, Sakoe K, Amaike M, Soutome M, Ogawa T, Nakano I, Nishizawa M (March 1999). "Single sperm analysis of the CAG repeats in the gene for dentatorubral-pallidoluysian atrophy (DRPLA): the instability of the CAG repeats in the DRPLA gene is prominent among the CAG repeat diseases". Human Molecular Genetics. 8 (3): 453–7. doi:10.1093/hmg/8.3.453. PMID9949204.
Okamura-Oho Y, Miyashita T, Ohmi K, Yamada M (June 1999). "Dentatorubral-pallidoluysian atrophy protein interacts through a proline-rich region near polyglutamine with the SH3 domain of an insulin receptor tyrosine kinase substrate". Human Molecular Genetics. 8 (6): 947–57. doi:10.1093/hmg/8.6.947. PMID10332026.
Dias Neto E, Correa RG, Verjovski-Almeida S, Briones MR, Nagai MA, da Silva W, Zago MA, Bordin S, Costa FF, Goldman GH, Carvalho AF, Matsukuma A, Baia GS, Simpson DH, Brunstein A, de Oliveira PS, Bucher P, Jongeneel CV, O'Hare MJ, Soares F, Brentani RR, Reis LF, de Souza SJ, Simpson AJ (March 2000). "Shotgun sequencing of the human transcriptome with ORF expressed sequence tags". Proceedings of the National Academy of Sciences of the United States of America. 97 (7): 3491–6. doi:10.1073/pnas.97.7.3491. PMC16267. PMID10737800.
Yanagisawa H, Bundo M, Miyashita T, Okamura-Oho Y, Tadokoro K, Tokunaga K, Yamada M (May 2000). "Protein binding of a DRPLA family through arginine-glutamic acid dipeptide repeats is enhanced by extended polyglutamine". Human Molecular Genetics. 9 (9): 1433–42. doi:10.1093/hmg/9.9.1433. PMID10814707.