Saint-Guily A, Schantz M L, Schantz R
Physiologie et Génétique végétales, Université Blaise Pascal, Clermont-Ferrand, France.
Plant Mol Biol. 1994 Mar;24(6):941-8. doi: 10.1007/BF00014447.
Screening of a lambda gt11 cDNA expression library of Euglena gracilis with antibodies directed against histones H2 from maize resulted in the isolation of a full-length cDNA for a histone H2A. The open-reading frame of 408 bp corresponded to a protein of 136 amino acid residues (14 kDa). Despite the presence of a poly(A) tail, which is typical of plant histone mRNA but not of animal histone mRNA, the size of the deduced protein and its percentage of homology were closer to animal histone H2As than to plant or lower eukaryotic histone H2A. Sequence alignment revealed that the Euglena H2A protein was characterized by a shorter C-terminus and a N-terminus which extended 10 residues past the animal H2A. In contrast to other organisms studied, the expression of the Euglena H2A gene appeared to be almost constant during an entire life-cycle and presented no cell-stage-specific expression during development. Similar results are obtained for another histone gene, H3, and for beta-tubulin. Regulation of gene expression at a post-transcriptional level seems to be a general feature of Euglena.
用针对玉米组蛋白H2的抗体筛选纤细裸藻的λgt11 cDNA表达文库，得到了一个组蛋白H2A的全长cDNA。408 bp的开放阅读框对应于一个由136个氨基酸残基组成的蛋白质（14 kDa）。尽管存在聚腺苷酸尾，这是植物组蛋白mRNA的典型特征而非动物组蛋白mRNA的特征，但推导蛋白质的大小及其同源百分比与动物组蛋白H2A更接近，而不是与植物或低等真核生物的组蛋白H2A接近。序列比对显示，裸藻H2A蛋白的特征是C端较短，N端比动物H2A延伸了10个残基。与其他研究的生物不同，裸藻H2A基因的表达在整个生命周期中似乎几乎恒定，在发育过程中没有细胞阶段特异性表达。另一个组蛋白基因H3和β-微管蛋白也得到了类似的结果。转录后水平的基因表达调控似乎是裸藻的一个普遍特征。
