Swanson D A, Steel J M, Valle D
Visual Neuroscience Training Program, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
Genomics. 1998 Mar 15;48(3):373-6. doi: 10.1006/geno.1997.5202.
In a screen designed to identify genes expressed preferentially in retina, we identified a cDNA encoding the human ortholog of rat STXBP1 (n-Sec1, Munc-18-1, rbSec1), a protein implicated in vesicle trafficking and neurotransmitter release. This protein also has similarity to Drosophila Rop (65% aa identity) and Caenorhabditis elegans UNC-18 (58% aa identity). The major human cDNA encodes a protein of 594 amino acids which has 100 % amino acid identity with its rat and murine counterparts. Additionally, there is an alternative splice form in humans, arising from the inclusion of an additional exon, which encodes a protein of 603 amino acids and is also 100% identical to the corresponding rat isoform. We found expression of the shorter cDNA in all tissues and cell lines we examined with highest levels in retina and cerebellum. By RT-PCR analysis, we found expression of the longer cDNA in neural tissues only. We mapped the structural gene to 9q34.1, a region without obvious candidate phenotypes. However, due to its evolutionary conservation and abundant expression in retina and brain, STXBP1 should be considered a candidate gene for retinal and/or neural disorders mapping to 9q34.1.
在一项旨在鉴定在视网膜中优先表达的基因的筛选中，我们鉴定出一个编码大鼠STXBP1（n-Sec1、Munc-18-1、rbSec1）人类直系同源物的cDNA，该蛋白与囊泡运输和神经递质释放有关。该蛋白还与果蝇Rop（氨基酸同一性为65%）和秀丽隐杆线虫UNC-18（氨基酸同一性为58%）相似。主要的人类cDNA编码一个由594个氨基酸组成的蛋白，该蛋白与其大鼠和小鼠对应物的氨基酸同一性为100%。此外，人类中存在一种可变剪接形式，由包含一个额外的外显子产生，该外显子编码一个由603个氨基酸组成的蛋白，并且也与相应的大鼠异构体100%相同。我们发现在我们检测的所有组织和细胞系中均有较短cDNA的表达，在视网膜和小脑中表达水平最高。通过RT-PCR分析，我们发现较长的cDNA仅在神经组织中表达。我们将该结构基因定位到9q34.1，这是一个没有明显候选表型的区域。然而，由于其进化保守性以及在视网膜和大脑中的丰富表达，STXBP1应被视为定位到9q34.1的视网膜和/或神经疾病的候选基因。
