The COOH-terminal Domain of the JIL-1 Histone H3S10 Kinase Interacts with Histone H3 and Is Required for Correct Targeting to Chromatin
The COOH-terminal Domain of the JIL-1 Histone H3S10 Kinase Interacts with Histone H3 and Is Required for Correct Targeting to Chromatin
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DOI：
10.1074/jbc.m806227200
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发表时间：
2008-11-21
影响因子：
4.8
通讯作者：
Johansen, Kristen M.
中科院分区：
文献类型：
--
作者：
Bao, Xiaomin;Cai, Weili;Johansen, Kristen M.
果蝇中的JIL-1组蛋白H3S10激酶定位于多线染色体的常染色质带间区，并在雄性X染色体上富含2倍。JIL-1可分为四个主要结构域，包括一个NH2-末端结构域、两个独立的激活区和一个COOH-末端结构域。我们的结果表明，JIL-1的COOH-末端结构域是正确的染色体靶向常染色体的必要条件和充分条件，但COOH-末端和NH2-末端序列对于男性X染色体的丰富是必需的。我们进一步证明了COOH-末端结构域中的一个小的53个氨基酸区域可以与组蛋白H3的尾部区域相互作用，这表明这种相互作用对于正确的染色质靶向JIL-1激酶是必要的。有趣的是，我们的数据表明，仅COOH-末端结构域就足以挽救JIL-1缺失突变的多线染色体缺陷，包括男性X染色体的缺陷。尽管如此，我们也发现截短的JIL-1蛋白没有COOH-末端结构域，但保留了组蛋白H3S10激酶活性，能够挽救常染色体，并部分挽救雄性X多线染色体的形态。综上所述，这些发现表明，JIL-1可能通过多种和部分冗余的机制参与染色质结构的调节。
The JIL-1 histone H3S10 kinase in Drosophila localizes specifically to euchromatic interband regions of polytene chromosomes and is enriched 2-fold on the male X chromosome. JIL-1 can be divided into four main domains including an NH2-terminal domain, two separate kinase domains, and a COOH-terminal domain. Our results demonstrate that the COOH-terminal domain of JIL-1 is necessary and sufficient for correct chromosome targeting to autosomes but that both COOH-and NH2-terminal sequences are necessary for enrichment on the male X chromosome. We furthermore show that a small 53-amino acid region within the COOH-terminal domain can interact with the tail region of histone H3, suggesting that this interaction is necessary for the correct chromatin targeting of the JIL-1 kinase. Interestingly, our data indicate that the COOH-terminal domain alone is sufficient to rescue JIL-1 null mutant polytene chromosome defects including those of the male X chromosome. Nonetheless, we also found that a truncated JIL-1 protein which was without the COOH-terminal domain but retained histone H3S10 kinase activity was able to rescue autosome as well as partially rescue male X polytene chromosome morphology. Taken together these findings indicate that JIL-1 may participate in regulating chromatin structure by multiple and partially redundant mechanisms.