title: Phosphorylation of an HP1-like protein is a prerequisite for heterochromatin body formation in Tetrahymena DNA elimination.
abstract: Multiple heterochromatic loci are often clustered into a higher order nuclear architecture called a heterochromatin body in diverse eukaryotes. Although phosphorylation of Heterochromatin Protein 1 (HP1) family proteins regulates heterochromatin dynamics, its role in heterochromatin bodies remains unknown. We previously reported that dephosphorylation of the HP1-like protein Pdd1p is required for the formation of heterochromatin bodies during the process of programmed DNA elimination in the ciliated protozoan Tetrahymena Here, we show that the heterochromatin body component Jub4p is required for Pdd1p phosphorylation, heterochromatin body formation, and DNA elimination. Moreover, our analyses of unphosphorylatable Pdd1p mutants demonstrate that Pdd1p phosphorylation is required for heterochromatin body formation and DNA elimination, whereas it is dispensable for local heterochromatin assembly. Therefore, both phosphorylation and the following dephosphorylation of Pdd1p are necessary to facilitate the formation of heterochromatin bodies. We suggest that Jub4p-mediated phosphorylation of Pdd1p creates a chromatin environment that is a prerequisite for subsequent heterochromatin body assembly and DNA elimination.
authors.affiliation: Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), A-1030 Vienna, Austria Kazufumi.Mochizuki@imba.oeaw.ac.at kensuke.kataoka@imba.oeaw.ac.at.
authors.forename: Kensuke
authors.identifier: 0000-0001-6113-289X
authors.initials: K
authors.lastname: Kataoka
authors.affiliation: Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), A-1030 Vienna, Austria.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Noto
authors.affiliation: Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), A-1030 Vienna, Austria Kazufumi.Mochizuki@imba.oeaw.ac.at kensuke.kataoka@imba.oeaw.ac.at.
authors.forename: Kazufumi
authors.initials: K
authors.lastname: Mochizuki
mesh_terms: D000090266:Chromobox Protein Homolog 5; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism*; D016054:DNA, Protozoan / Q000378:metabolism*; D006570:Heterochromatin / Q000502:physiology*; D009687:Nuclear Proteins / Q000378:metabolism*; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation; D015800:Protozoan Proteins / Q000378:metabolism*; D013768:Tetrahymena / Q000235:genetics*
chemical_list: D002868:Chromosomal Proteins, Non-Histone; D016054:DNA, Protozoan; D006570:Heterochromatin; D009687:Nuclear Proteins; C101880:Pdd1 protein, Tetrahymena; D010750:Phosphoproteins; D015800:Protozoan Proteins; D000090266:Chromobox Protein Homolog 5
keywords: DNA elimination; HP1 phosphorylation; Tetrahymena; heterochromatin body