Heterochromatin and RNAi are required to establish CENP-A chromatin at centromeres.
Heterochromatin is defined by distinct posttranslational modifications on histones, such as methylation of histone H3 at lysine 9 (H3K9), which allows heterochromatin protein 1 (HP1)-related chromodomain proteins to bind. Heterochromatin is frequently found near CENP-A chromatin, which is the key determinant of kinetochore assembly. We have discovered that the RNA interference (RNAi)-directed heterochromatin flanking the central kinetochore domain at fission yeast centromeres is required to promote CENP-A(Cnp1) and kinetochore assembly over the central domain. The H3K9 methyltransferase Clr4 (Suv39); the ribonuclease Dicer, which cleaves heterochromatic double-stranded RNA to small interfering RNA (siRNA); Chp1, a component of the RNAi effector complex (RNA-induced initiation of transcriptional gene silencing; RITS); and Swi6 (HP1) are required to establish CENP-A(Cnp1) chromatin on naïve templates. Once assembled, CENP-A(Cnp1) chromatin is propagated by epigenetic means in the absence of heterochromatin. Thus, another, potentially conserved, role for centromeric RNAi-directed heterochromatin has been identified.
Folco
Hernan Diego
HD
Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, 6.34 Swann Building, Edinburgh EH9 3JR, Scotland, UK.
Pidoux
Alison L
AL
Urano
Takeshi
T
Allshire
Robin C
RC
D018797:Cell Cycle Proteins / Q000378:metabolism; D002503:Centromere / Q000378:metabolism*; D002843:Chromatin / Q000378:metabolism*; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism*; D020090:Chromosome Segregation; D015825:Chromosomes, Fungal / Q000235:genetics / Q000378:metabolism; D004271:DNA, Fungal / Q000235:genetics / Q000378:metabolism; D044127:Epigenesis, Genetic; D006570:Heterochromatin / Q000378:metabolism*; D011495:Histone-Lysine N-Methyltransferase; D018386:Kinetochores / Q000378:metabolism; D008780:Methyltransferases / Q000378:metabolism; D034622:RNA Interference; D012331:RNA, Fungal / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D043244:Ribonuclease III / Q000378:metabolism; D012568:Schizosaccharomyces / Q000235:genetics / Q000378:metabolism*; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000378:metabolism*; D014170:Transformation, Genetic
D018797:Cell Cycle Proteins; C115018:Chp1 protein, S pombe; D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; C410349:Cnp1 protein, S pombe; D004271:DNA, Fungal; D006570:Heterochromatin; D012331:RNA, Fungal; D034741:RNA, Small Interfering; D029702:Schizosaccharomyces pombe Proteins; C465958:Swi6 protein, S pombe; D008780:Methyltransferases; D011495:Histone-Lysine N-Methyltransferase; C112744:clr4 protein, S pombe; D043244:Ribonuclease III