Zhang K, Howes K A, He W, Bronson J D, Pettenati M J, Chen C, Palczewski K, Wensel T G, Baehr W
Moran Eye Center, University of Utah, Salt Lake City, UT, USA.
Gene. 1999 Nov 15;240(1):23-34. doi: 10.1016/s0378-1119(99)00393-5.
An isoform of RGS9 was recently identified as the GTPase activating protein in bovine and mouse rod and cone photoreceptors. To explore the potential role of the RGS9 gene in human retinal disease, we determined its exon/intron arrangement, and investigated its expression in human retina. The results show that the gene, located on 17q24, consists of 19 exons and spans more than 75kb of genomic DNA. The entire gene was found to be contained on a single BAC clone with an insert size of 170kb. The major transcripts of the gene are alternatively spliced into a 9.5kb retina-specific transcript (RGS9-1) and a brain specific 2.5kb transcript (RGS9-2). Exons 1-16 are constitutive and present in both variants. Exon 17 contains the 3' end of the open reading frame and the 3'-UTR of the RGS9-1 variant. In RGS9-2, exon 17 is alternatively spliced and joined to exons 18 and 19 that are not present in the retina variant. Immunolocalization with a monoclonal antibody recognizing the retina and brain variants shows abundant expression in photoreceptors and possibly very low levels in cell types of the inner retina. Owing to the specific expression of RGS9-1 in photoreceptors the RGS9 gene is a candidate gene for RP17, a form of autosomal retinitis pigmentosa, located on the long arm of chromosome 17.
最近，RGS9的一种同工型被鉴定为牛和小鼠视杆及视锥光感受器中的GTP酶激活蛋白。为了探究RGS9基因在人类视网膜疾病中的潜在作用，我们确定了其外显子/内含子排列，并研究了其在人类视网膜中的表达。结果显示，该基因位于17q24，由19个外显子组成，跨越超过75kb的基因组DNA。整个基因被发现包含在一个插入片段大小为170kb的单一BAC克隆中。该基因的主要转录本被选择性剪接成一个9.5kb的视网膜特异性转录本（RGS9-1）和一个2.5kb的脑特异性转录本（RGS9-2）。外显子1-16是组成型的，存在于两种变体中。外显子17包含开放阅读框的3'末端和RGS9-1变体的3'-UTR。在RGS9-2中，外显子17被选择性剪接，并与视网膜变体中不存在的外显子18和19连接。用识别视网膜和脑变体的单克隆抗体进行免疫定位显示，在光感受器中有丰富的表达，在内层视网膜的细胞类型中可能表达水平非常低。由于RGS9-1在光感受器中的特异性表达，RGS9基因是位于17号染色体长臂上的常染色体隐性视网膜色素变性形式RP17的候选基因。
