title: Phosphorylation of Swi6/HP1 regulates transcriptional gene silencing at heterochromatin.
abstract: Heterochromatin protein 1 (HP1) recruits various effectors to heterochromatin for multiple functions, but its regulation is unclear. In fission yeast, a HP1 homolog Swi6 recruits SHREC, Epe1, and cohesin, which are involved in transcriptional gene silencing (TGS), transcriptional activation, and sister chromatid cohesion, respectively. We found that casein kinase II (CK2) phosphorylated Swi6. Loss of CK2-dependent Swi6 phosphorylation alleviated heterochromatic TGS without affecting heterochromatin structure. This was due to the inhibited recruitment of SHREC to heterochromatin, accompanied by an increase in Epe1. Interestingly, loss of phosphorylation did not affect cohesion. These results indicate that CK2-dependent Swi6 phosphorylation specifically controls TGS in heterochromatin.
authors.affiliation: Laboratory of Signal Transduction, Department of Cell Biology, Institute for Virus Research, Kyoto University, Kyoto, Kyoto 606-8507, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Shimada
authors.forename: Kohei
authors.initials: K
authors.lastname: Dohke
authors.forename: Mahito
authors.initials: M
authors.lastname: Sadaie
authors.forename: Kaori
authors.initials: K
authors.lastname: Shinmyozu
authors.forename: Jun-Ichi
authors.initials: J
authors.lastname: Nakayama
authors.forename: Takeshi
authors.initials: T
authors.lastname: Urano
authors.forename: Yota
authors.initials: Y
authors.lastname: Murakami
mesh_terms: D047390:Casein Kinase II / Q000235:genetics / Q000378:metabolism; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D020868:Gene Silencing / Q000502:physiology*; D006570:Heterochromatin / Q000378:metabolism*; D010766:Phosphorylation; D012568:Schizosaccharomyces / Q000235:genetics / Q000378:metabolism*; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D002868:Chromosomal Proteins, Non-Histone; D006570:Heterochromatin; D029702:Schizosaccharomyces pombe Proteins; C465958:Swi6 protein, S pombe; D047390:Casein Kinase II; C479661:casein kinase II, S pombe