Organization of serpin gene-1 from Manduca sexta - Evolution of a family of alternate exons encoding the reactive site loop
Organization of serpin gene-1 from Manduca sexta - Evolution of a family of alternate exons encoding the reactive site loop
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DOI：
10.1074/jbc.271.45.28017
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发表时间：
1996-11-08
影响因子：
4.8
通讯作者：
Kanost, MR
中科院分区：
文献类型：
--
作者：
Jiang, HB;Wang, Y;Kanost, MR
Manduca sexta serpin基因-1编码一个氨基酸序列相同的蛇类家族，其氨基酸序列在氨基末端336个残基上相同，而在其羧基末端39-46个残基上变异，包括反应位点环(酱，H.，Wang，Y.和Kanost，M.R.(1994)J.Biol)。化学，269，55-58)。在这里，我们报告了该基因的完整核苷酸序列和外显子-内含子结构。该基因的一个独特特征是它的外显子9，它存在于外显子8和10之间的12种交替形式中。对包含以前没有发现的外显子9C、9H和9I的cDNA克隆的分离和鉴定表明，所有12种不同形式的外显子9都可以用来产生12种不同的蛇。剪接途径显然只允许每个成熟的Serpin-1mRNA分子包含一个外显子9。对外显子-内含子边界序列的分析揭示了可能参与调控RNA剪接的独特特征。外显子9区显然是通过几轮外显子复制和序列差异而进化的。该区域中心附近的外显子可能是最近进化的，而最外层的外显子是最古老的。外显子9G和9H作为外显子9E和9F的一对复制，这一事件在该基因的历史上可能发生过不止一次。
Manduca sexta serpin gene-1 encodes a family of serpins whose amino acid sequences are identical in their amino terminal 336 residues but variable in their carboxyl-terminal 39-46 residues, which includes the reactive site loop (Jiang, H., Wang, Y., and Kanost, M.R. (1994) J. Biol. Chem, 269, 55-58). Here, we report the gene's complete nucleotide sequence and exon-intron structure. A unique characteristic of this gene is its exon 9, which is present in 12 alternate forms between exons 8 and 10. Isolation and characterization of cDNA clones containing exons 9C, 9H, and 9I, which were not found previously, indicate that all 12 alternate forms of exon 9 can be utilized to generate 12 different serpins. The splicing pathway apparently allows inclusion of only one exon 9 per molecule of mature serpin-1 mRNA. Analysis of exon-intron border sequences reveals unique features that may be involved in regulation of RNA splicing. The exon 9 region has apparently evolved through rounds of exon duplication and sequence divergence. The exons near the center of the region may have evolved recently, whereas the outermost exons are the most ancient. Exons 9G and 9H were duplicated as a pair from exons 9E and 9F, an event that may have occurred more than once in the history of this gene.