[RNAi and the formation of heterochromatin in Schizosaccharomyces pombe.].
In the fission yeast Schizosaccharomyces pombe, formation of pericentromeric heterochromatin involves RNA interference (RNAi). Recent data indicate that two RNAi complexes, RITS (RNA-induced transcriptional silencing complex) and RDRC (RNA-directed RNA polymerase complex), their respective enzymatic activity, and RNA polymerase II are essential for RNAi-mediated heterochromatin formation. At the site where heterochromatin formation takes place, RNA polymerase II synthesizes an RNA that would serve as an RNA platform to recruit in a siRNA-dependent manner RITS and RDRC, and thereby initiate heterochromatin assembly. Once recruited, RITS and RDRC seem to also contribute to the processing of the RNA platform. Therefore, RNAi-driven heterochromatin assembly appears to take place through a dynamic process of RNA synthesis, RNA-dependant recruitment of RNAi complexes and RNA degradation that all occur in cis.
Institut National de la Santé et de la Recherche Médicale, U823, Institut Albert Bonniot - Université Joseph Fourier, F-38700 Grenoble, France.
Sophie
S
Barral
Aurélia
A
Vavasseur
André
A
Verdel
D002467:Cell Nucleus / Q000378:metabolism; D004722:Endoribonucleases / Q000502:physiology; D015966:Gene Expression Regulation, Fungal / Q000235:genetics*; D006570:Heterochromatin / Q000235:genetics*; D008957:Models, Genetic; D009707:Nucleosomes / Q000648:ultrastructure; D034622:RNA Interference; D012319:RNA Polymerase II / Q000235:genetics; D020871:RNA Stability; D012330:RNA, Double-Stranded / Q000096:biosynthesis / Q000235:genetics; D012331:RNA, Fungal / Q000096:biosynthesis / Q000235:genetics*; D012324:RNA-Dependent RNA Polymerase / Q000235:genetics; D034743:RNA-Induced Silencing Complex / Q000235:genetics; D012568:Schizosaccharomyces / Q000235:genetics*; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000502:physiology
D006570:Heterochromatin; D009707:Nucleosomes; D012330:RNA, Double-Stranded; D012331:RNA, Fungal; D034743:RNA-Induced Silencing Complex; D029702:Schizosaccharomyces pombe Proteins; D012319:RNA Polymerase II; D012324:RNA-Dependent RNA Polymerase; C568524:Dcr1 protein, S pombe; D004722:Endoribonucleases