Dou Y, Gorovsky M A
Department of Biology, University of Rochester, New York 14627, USA.
Mol Cell. 2000 Aug;6(2):225-31. doi: 10.1016/s1097-2765(00)00024-1.
In Tetrahymena, histone H1 phosphorylation can regulate transcription and mimics loss of H1 from chromatin. We investigated the mechanism by which H1 phosphorylation affects transcription. Tetrahymena strains were created containing mutations in H1 that mimicked the charge of the phosphorylated region without mimicking the structure or increased hydrophilicity of the phosphorylated residues. Whenever the charge resembled that of the phosphorylated state, the induced expression of the CyP1 gene was greatly inhibited. Whenever the charge was similar to that of the dephosphorylated state, the CyP1 gene was induced normally. These results argue strongly that phosphorylation of H1 acts by changing the overall charge of a small domain, not by phosphate recognition or by creating a site-specific charge.
在四膜虫中，组蛋白H1磷酸化可调节转录，并模拟染色质中H1的缺失。我们研究了H1磷酸化影响转录的机制。构建了四膜虫菌株，其中H1发生突变，模拟了磷酸化区域的电荷，但没有模拟磷酸化残基的结构或增加亲水性。只要电荷与磷酸化状态相似，CyP1基因的诱导表达就会受到极大抑制。只要电荷与去磷酸化状态相似，CyP1基因就能正常诱导表达。这些结果有力地表明，H1的磷酸化是通过改变一个小结构域的整体电荷来发挥作用的，而不是通过磷酸识别或产生位点特异性电荷来发挥作用。
