Huh G H, Matsuura Y, Meshi T, Iwabuchi M
Department of Botany, Faculty of Science, Kyoto University, Japan.
Biochim Biophys Acta. 1995 Mar 14;1261(1):155-60. doi: 10.1016/0167-4781(95)00017-b.
Five histone H2A cDNA clones have been isolated from a wheat cDNA library. They were divided into two groups, termed type 1 and type 2, based on their deduced amino acid sequences and their gene expression patterns. Three type 1 clones had ORFs encoding proteins similar to angiosperm histone H2As known so far, whereas two type 2 clones encoded an identical protein, which was more similar to Norway spruce (gymnosperm) H2A than to the angiosperm H2As. The C-terminus of the type 2 H2A was shorter than that of the type 1 H2As and lacked the characteristic SPKK motif that is conserved in angiosperm H2As. Northern analysis revealed that the mRNA levels of the type 1 H2A genes were high in proliferating cells during germination and in various tissues of young seedlings, while the mRNA levels of the type 2 genes were high in non-proliferating cells in which the type 1 gene was poorly expressed. This result suggests that the expression of these two groups of H2A genes is differently regulated during development in wheat.
从小麦cDNA文库中分离出了五个组蛋白H2A cDNA克隆。根据其推导的氨基酸序列和基因表达模式，它们被分为两组，分别称为1型和2型。三个1型克隆具有开放阅读框，编码的蛋白质与迄今为止已知的被子植物组蛋白H2A相似，而两个2型克隆编码一种相同的蛋白质，该蛋白质与挪威云杉（裸子植物）的H2A比与被子植物的H2A更相似。2型H2A的C末端比1型H2A的C末端短，并且缺乏在被子植物H2A中保守的特征性SPKK基序。Northern分析表明，1型H2A基因的mRNA水平在萌发期间的增殖细胞和幼苗的各种组织中较高，而2型基因的mRNA水平在1型基因表达较差的非增殖细胞中较高。这一结果表明，在小麦发育过程中，这两组H2A基因的表达受到不同的调控。
