title: Drosophila CAF-1 regulates HP1-mediated epigenetic silencing and pericentric heterochromatin stability.
abstract: Chromatin assembly factor 1 (CAF-1) was initially characterized as a histone deliver in the process of DNA-replication-coupled chromatin assembly in eukaryotic cells. Here, we report that CAF-1 p180, the largest subunit of Drosophila CAF-1, participates in the process of heterochromatin formation and functions to maintain pericentric heterochromatin stability. We provide evidence that Drosophila CAF-1 p180 plays a role in both classes of position effect variegation (PEV) and in the expression of heterochromatic genes. A decrease in the expression of Drosophila CAF-1 p180 leads to a decrease in both H3K9 methylation at pericentric heterochromatin regions and the recruitment of heterochromatin protein 1 (HP1) to the chromocenter of the polytene chromosomes. The artificial targeting of HP1 to a euchromatin location leads to the enrichment of Drosophila CAF-1 p180 at this ectopic heterochromatin, suggesting the mutual recruitment of HP1 and CAF-1 p180. We also show that the spreading of heterochromatin is compromised in flies that have reduced CAF-1 p180. Furthermore, reduced CAF-1 p180 causes a defect in the dynamics of heterochromatic markers in early Drosophila embryos. Together, these findings suggest that Drosophila CAF-1 p180 is an essential factor in the epigenetic control of heterochromatin formation and/or maintenance.
authors.affiliation: State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Hai
authors.initials: H
authors.lastname: Huang
authors.forename: Zhongsheng
authors.initials: Z
authors.lastname: Yu
authors.forename: Shuaiqi
authors.initials: S
authors.lastname: Zhang
authors.forename: Xuehong
authors.initials: X
authors.lastname: Liang
authors.forename: Jianming
authors.initials: J
authors.lastname: Chen
authors.forename: Changqing
authors.initials: C
authors.lastname: Li
authors.forename: Jun
authors.initials: J
authors.lastname: Ma
authors.forename: Renjie
authors.initials: R
authors.lastname: Jiao
mesh_terms: D000818:Animals; D004330:Drosophila / Q000235:genetics*; D029721:Drosophila Proteins / Q000235:genetics* / Q000378:metabolism; D044127:Epigenesis, Genetic; D005786:Gene Expression Regulation; D020868:Gene Silencing; D006570:Heterochromatin / Q000235:genetics* / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D056505:Retinoblastoma-Binding Protein 4 / Q000235:genetics* / Q000378:metabolism
chemical_list: C110251:Caf1-55 protein, Drosophila; D029721:Drosophila Proteins; D006570:Heterochromatin; D012097:Repressor Proteins; D056505:Retinoblastoma-Binding Protein 4