Lee J S, Choe J, Park E H
Department of Biology, College of Natural Sciences, Hanyang University, Seoul, South Korea.
Biochem Mol Biol Int. 1994 Nov;34(5):921-6.
We have cloned ras genes from the hermaphroditic fish Rivulus marmoratus genomic library by screening about 3.0 x 10(5) genomic clones. When one out of 19 ras genomic clones was sequenced, it showed 95.8% amino acid homology to the human c-Ha-ras gene and was named the Rivulus c-Ha-ras gene. The Rivulus c-Ha-ras gene spanned about 3.7 kb and consisted of four exons encoding 189 amino acids. The exon-intron boundaries also coincided with the rule of GT/AG of consensus splice acceptor and donor sequences. The Rivulus c-Ha-ras gene does not, however, have the intron-D-exon (IDX) that has been reported to exist between the third and the fourth exon of the mammalian c-Ha-ras genes, and which is involved in negative control of p21 c-Ha-ras expression and transforming activity of this gene. This is the first report on the structure of the fish c-Ha-ras gene.
我们通过筛选约3.0×10⁵个基因组克隆，从雌雄同体的鱼类——弹涂鱼的基因组文库中克隆了ras基因。在19个ras基因组克隆中，有一个经测序后发现，其与人类c-Ha-ras基因的氨基酸同源性为95.8%，并被命名为弹涂鱼c-Ha-ras基因。弹涂鱼c-Ha-ras基因跨度约3.7 kb，由四个外显子组成，编码189个氨基酸。外显子-内含子边界也符合共有剪接受体和供体序列的GT/AG规则。然而，弹涂鱼c-Ha-ras基因没有内含子-D-外显子（IDX），据报道，该序列存在于哺乳动物c-Ha-ras基因的第三和第四外显子之间，并且参与p21 c-Ha-ras表达的负调控以及该基因的转化活性。这是关于鱼类c-Ha-ras基因结构的首次报道。
