Banfi S, Servadio A, Chung M Y, Kwiatkowski T J, McCall A E, Duvick L A, Shen Y, Roth E J, Orr H T, Zoghbi H Y
Department of Pediatrics, Baylor College of Medicine, Houston, Texas 77030.
Nat Genet. 1994 Aug;7(4):513-20. doi: 10.1038/ng0894-513.
Spinocerebellar ataxia type 1 (SCA1) is a neurodegenerative disorder caused by expansion of a CAG trinucleotide repeat. In this study, we describe the identification and characterization of the gene harbouring this repeat. The SCA1 transcript is 10,660 bases and is transcribed from both the wild type and SCA1 alleles. The CAG repeat, coding for a polyglutamine tract, lies within the coding region. The gene spans 450 kb of genomic DNA and is organized in nine exons. The first seven fall in the 5' untranslated region and the last two contain the coding region, and a 7,277 basepairs 3' untranslated region. The first four non-coding exons undergo alternative splicing in several tissues. These features suggest that the transcriptional and translational regulation of ataxin-1, the SCA1 encoded protein, may be complex.
1型脊髓小脑共济失调（SCA1）是一种由CAG三核苷酸重复序列扩增引起的神经退行性疾病。在本研究中，我们描述了携带该重复序列的基因的鉴定和特征。SCA1转录本为10660个碱基，由野生型和SCA1等位基因转录而来。编码聚谷氨酰胺序列的CAG重复序列位于编码区内。该基因跨越450kb的基因组DNA，由9个外显子组成。前7个外显子位于5'非翻译区，后2个外显子包含编码区以及一个7277个碱基对的3'非翻译区。前4个非编码外显子在多个组织中发生可变剪接。这些特征表明，SCA1编码的蛋白ataxin-1的转录和翻译调控可能很复杂。
