title: Domain requirements of the JIL-1 tandem kinase for histone H3 serine 10 phosphorylation and chromatin remodeling in vivo.
abstract: The JIL-1 kinase localizes to Drosophila polytene chromosome interbands and phosphorylates histone H3 at interphase, counteracting histone H3 lysine 9 dimethylation and gene silencing. JIL-1 can be divided into four main domains, including an NH2-terminal domain, two separate kinase domains, and a COOH-terminal domain. In this study, we characterize the domain requirements of the JIL-1 kinase for histone H3 serine 10 (H3S10) phosphorylation and chromatin remodeling in vivo. We show that a JIL-1 construct without the NH2-terminal domain is without H3S10 phosphorylation activity despite the fact that it localizes properly to polytene interband regions and that it contains both kinase domains. JIL-1 is a double kinase, and we demonstrate that both kinase domains of JIL-1 are required to be catalytically active for H3S10 phosphorylation to occur. Furthermore, we provide evidence that JIL-1 is phosphorylated at serine 424 and that this phosphorylation is necessary for JIL-1 H3S10 phosphorylation activity. Thus, these data are compatible with a model where the NH2-terminal domain of JIL-1 is required for chromatin complex interactions that position the kinase domain(s) for catalytic activity in the context of the state of higher order nucleosome packaging and chromatin structure and where catalytic H3S10 phosphorylation activity mediated by the first kinase domain is dependent on autophosphorylation of serine 424 by the second kinase domain. Furthermore, using a lacO repeat tethering system to target mutated JIL-1 constructs with or without catalytic activity, we show that the epigenetic H3S10 phosphorylation mark itself functions as a causative regulator of chromatin structure independently of any structural contributions from the JIL-1 protein.
authors.affiliation: Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa 50011, USA.
authors.forename: Yeran
authors.initials: Y
authors.lastname: Li
authors.forename: Weili
authors.initials: W
authors.lastname: Cai
authors.forename: Chao
authors.initials: C
authors.lastname: Wang
authors.forename: Changfu
authors.initials: C
authors.lastname: Yao
authors.forename: Xiaomin
authors.initials: X
authors.lastname: Bao
authors.forename: Huai
authors.initials: H
authors.lastname: Deng
authors.forename: Jack
authors.initials: J
authors.lastname: Girton
authors.forename: Jørgen
authors.initials: J
authors.lastname: Johansen
authors.forename: Kristen M
authors.initials: KM
authors.lastname: Johansen
mesh_terms: D000818:Animals; D002843:Chromatin / Q000235:genetics / Q000378:metabolism*; D042002:Chromatin Assembly and Disassembly / Q000502:physiology*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster; D044127:Epigenesis, Genetic / Q000502:physiology*; D006657:Histones / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D010766:Phosphorylation / Q000502:physiology; D059007:Polytene Chromosomes / Q000235:genetics / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D012694:Serine / Q000235:genetics / Q000378:metabolism
chemical_list: D002843:Chromatin; D029721:Drosophila Proteins; D006657:Histones; D012694:Serine; C507306:JIL-1 protein, Drosophila; D017346:Protein Serine-Threonine Kinases
keywords: Chromatin Histone Modification; Chromatin Remodeling; Drosophila; H3S10 Phosphorylation; JIL-1 Kinase; Phosphorylation; Protein Kinases