新基因水稻OsLSD1的克隆及拟南芥和水稻类LSD1基因家族的生物信息学分析

Cloning of a Novel Rice Gene OsLSD1 and Bioinformatic Analysis of LSD1-like Gene Family From Arabidopsis and Rice

类LSD1(LSD1-like) 基因家族是一类特殊的C2C2型锌指蛋白基因,编码植物特有的转录因子. 目前已经研究的2个成员拟南芥LSD1(lesions stimulating disease resistance 1) 和LOL1(LSD-One-Like 1) 基因均参与植物细胞程序化死亡(programmed cell death, PCD) 的调控. 从水稻cDNA文库中克隆到1个类LSD1基因,命名为OsLSD1. 该基因长988 bp,包含一个432 bp的开放阅读框,推导的氨基酸序列(143个氨基酸) 含有3个内部保守的锌指结构域. DNA印迹结果表明OsLSD1基因在水稻基因组中为单拷贝,且在根、茎和叶中表达. 借助于生物信息学分析技术,从拟南芥和水稻数据库中各识别出5个和7个(包括OsLSD1) 类LSD1基因. 分析了这些类LSD1基因的结构,蛋白质结构域组成. 系统进化分析表明,无论基于编码区的核苷酸或氨基酸序列都可以将这些类LSD1基因分为2类. 虽然不存在拟南芥或水稻特有的类LSD1蛋白,但有些结构域是水稻所特有的,也有些基因是来源于复制事件.

LSD1-like proteins are a family of plant-specific transcription factors that contain a specific class of C2C2 type zinc finger domain. Two members of this family have been identified and proved to control plant programmed cell death (PCD) in Arabidopsis. Here, a novel rice LSD1-like gene was cloned from a cDNA library and designated as OsLSD1 (for Oryza sativa LSD1). The cDNA is 988 bp in size, containing an open reading frame of 432 bp. The predicted OsLSD1 protein (143 amino acid residues) contains three internally conserved zinc finger domains. Southern blot indicated that OsLSD1 is a single-copy gene in rice. Furthermore, the OsLSD1 gene was expressed constitutively in rice root, stem and leaf. Using Bioinformatic tool, five and seven LSD1-like genes were identified from the databases of Arabidopsis and rice, respectively. The gene structure and domain organization of these LSD1-like genes were determined. Phylogenetic analysis of their coding sequences and predicted amino acid sequences suggested these genes can be classified into two classes, and a gene duplication event was identified. Although there is no specific class of LSD1-like gene in Arabidopsis or rice, some rice-specific zinc finger domains are found.