Bao, X., Cai, W., Deng, H., Zhang, W., Krencik, R., Girton, J., Johansen, J., Johansen, K.M. (2008). The COOH-terminal domain of the JIL-1 histone H3S10 kinase interacts with histone H3 and is required for correct targeting to chromatin.  J. Biol. Chem. 283(47): 32741--32750.

FBrf0207132

Research paper

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 NH(2)-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 NH(2)-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.

PMC2583313 (PMC) (EuropePMC)