Waterborg J H
Division of Cell Biology and Biophysics, School of Basic Life Sciences, University of Missouri--Kansas City 64110-2499.
Biochemistry. 1992 Jul 14;31(27):6211-9. doi: 10.1021/bi00142a006.
Radioactive acetylation in vivo of plant histone H4 of alfalfa, Arabidopsis, tobacco, and carrot revealed five distinct forms of radioactive, acetylated histone. In histone H4 of eukaryotes ranging from fungi to man, acetylation is restricted to four lysines (residues 5, 8, 12, and 16) possibly caused by a quantitative methylation of lysine-20. Chemical and proteolytic fragmentation of the amino terminally blocked alfalfa H4 protein, dynamically acetylated by radioactive acetate in vivo, allowed protein sequencing and identification of selected peptides. Peptide identification was facilitated by analyzing fully characterized calf histone H4 in parallel. Acetylation in vivo of alfalfa histone H4 was restricted to the lysines in the amino-terminal domain of the protein, residues 1-23. Lysine-20 was shown to be free of methylation, as in pea histone H4. This apparently makes lysine-20 accessible as a novel target for histone acetylation. The in vivo pattern of lysine acetylation (16 greater than 12 greater than 8 greater than or equal to 5 = 20) revealed a preference for lysines -16 and -12 without an apparent strict sequential specificity of acetylation.
苜蓿、拟南芥、烟草和胡萝卜的植物组蛋白H4在体内的放射性乙酰化显示出五种不同形式的放射性乙酰化组蛋白。在从真菌到人类的真核生物的组蛋白H4中，乙酰化仅限于四个赖氨酸（第5、8、12和16位残基），这可能是由赖氨酸-20的定量甲基化引起的。通过体内放射性乙酸盐动态乙酰化的氨基末端被封闭的苜蓿H4蛋白的化学和蛋白水解片段化，实现了蛋白质测序和选定肽段的鉴定。通过平行分析完全表征的小牛组蛋白H4促进了肽段鉴定。苜蓿组蛋白H4在体内的乙酰化仅限于蛋白质氨基末端结构域中的赖氨酸，即第1-23位残基。如豌豆组蛋白H4一样，赖氨酸-20未发生甲基化。这显然使赖氨酸-20成为组蛋白乙酰化的一个新靶点。赖氨酸乙酰化的体内模式（16＞12＞8≥5 = 20）显示对赖氨酸-16和-12有偏好，且没有明显严格的乙酰化顺序特异性。
