The COOH-terminal domain of the JIL-1 histone H3S10 kinase interacts with histone H3 and is required for correct targeting to chromatin.
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.
Bao
Xiaomin
X
Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa 50011, USA.
Cai
Weili
W
Deng
Huai
H
Zhang
Weiguo
W
Krencik
Robert
R
Girton
Jack
J
Johansen
Jørgen
J
Johansen
Kristen M
KM
D000818:Animals; D002843:Chromatin / Q000737:chemistry*; D002875:Chromosomes / Q000648:ultrastructure; D029721:Drosophila Proteins / Q000737:chemistry* / Q000378:metabolism; D004331:Drosophila melanogaster; D017353:Gene Deletion; D006657:Histones / Q000737:chemistry*; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D008968:Molecular Conformation; D009154:Mutation; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry* / Q000378:metabolism; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000737:chemistry
D002843:Chromatin; D029721:Drosophila Proteins; D006657:Histones; D011993:Recombinant Fusion Proteins; C507306:JIL-1 protein, Drosophila; D017346:Protein Serine-Threonine Kinases