The H1 histone variant of tomato, H1-S, is targeted to the nucleus and accumulates in chromatin in response to water-deficit stress
The H1 histone variant of tomato, H1-S, is targeted to the nucleus and accumulates in chromatin in response to water-deficit stress
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DOI：
10.1007/s004250000278
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发表时间：
2000-07
期刊：
影响因子：
4.3
通讯作者：
G. Scippa;A. Griffiths;D. Chiatante;E. Bray
中科院分区：
文献类型：
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作者：
G. Scippa;A. Griffiths;D. Chiatante;E. Bray
水分亏缺对基因表达模式有显著影响。根据推测的氨基酸序列，提出了番茄（lycopersiicon esculentumMill.）干旱和脱落酸诱导基因（his1-s）编码H1组蛋白变异。为了研究H1-S的作用，了解其表达特性是非常重要的。为了在体内鉴定his1-s产物，将his1- scdna融合到（His）6标签并在大肠杆菌中过表达。利用H1-S融合蛋白生成一种抗体，该抗体能识别一种表观分子量为31 kDa的蛋白质，这种蛋白质是在整个植物和离体叶片中对水分缺乏作出反应而积累的。his1表达的时间过程表明，与整个植株和离体叶片的mRNA积累相比，蛋白质积累延迟。利用细胞分离、免疫荧光和H1-S::β-葡萄糖醛酸酶融合分析转基因组织中H1-S的细胞定位。结果表明，H1-S在番茄萎蔫叶片的细胞核中积累，并与染色质有关。干旱和脱落酸诱导的基因his1编码一种连接组蛋白亚型，这种连接组蛋白亚型特异性地积累在遭受缺水条件的番茄叶片的细胞核和染色质中。尽管H1-S功能的分子机制尚不清楚，但H1-S的表达特征与该蛋白在水分亏缺反应中调控基因表达的潜在作用是一致的。
Water deficit has a significant impact on patterns of gene expression. Based on the deduced amino acid sequence, it has been proposed that the drought and abscisic acid-induced gene (his1-s) of tomato (Lycopersicon esculentumMill.) encodes an H1 histone variant. To study the role of H1-S it is important to understand the expression characteristics of the protein. To identify thehis1-sproduct in vivo thehis1-scDNA was fused to a (His)6tag and overexpressed inEscherichiacoli. The H1-S fusion protein was used to generate an antibody that recognized a protein with an apparent molecular weight of 31 kDa that accumulates in response to water deficit in the whole plant and detached leaves. A time course ofhis1-sexpression showed that protein accumulation is delayed compared to the mRNA accumulation in both the whole plant and detached leaves. Cellular fractionation, immunofluorescence and H1-S::β-glucuronidase fusion analyses in transgenic tissues were used to determine the cellular localization of H1-S. The results showed that H1-S accumulates in nuclei and is associated with chromatin of wilted tomato leaves. The drought- and abscisic acid-induced genehis1-sencodes a linker-histone subtype specifically accumulated in the nuclei and chromatin of tomato leaves subjected to water-deficit conditions. Although the molecular mechanism of H1-S function is still unclear, the expression characteristics of H1-S are consistent with a potential role of this protein in the regulation of gene expression in response to water deficit.