%0 Journal Article %T Two RNAi complexes, RITS and RDRC, physically interact and localize to noncoding centromeric RNAs. %+ Department of cell biology %+ Taplin Biological Mass Spectrometry Facility %A Motamedi, Mohammad R %A Verdel, André %A Colmenares, Serafin U %A Gerber, Scott A %A Gygi, Steven P %A Moazed, Danesh %< avec comité de lecture %@ 0092-8674 %J Cell %I Elsevier %V 119 %N 6 %P 789-802 %8 2004-12-17 %D 2004 %R 10.1016/j.cell.2004.11.034 %M 15607976 %Z Life Sciences [q-bio]/GeneticsJournal articles %X RNAi-mediated heterochromatin assembly in fission yeast requires the RNA-induced transcriptional silencing (RITS) complex and a putative RNA-directed RNA polymerase (Rdp1). Here we show that Rdp1 is associated with two conserved proteins, Hrr1, an RNA helicase, and Cid12, a member of the polyA polymerase family, in a complex that has RNA-directed RNA polymerase activity (RDRC, RNA-directed RNA polymerase complex). RDRC physically interacts with RITS in a manner that requires the Dicer ribonuclease (Dcr1) and the Clr4 histone methyltransferase. Moreover, both complexes are localized to the nucleus and associate with noncoding centromeric RNAs in a Dcr1-dependent manner. In cells lacking Rdp1, Hrr1, or Cid12, RITS complexes are devoid of siRNAs and fail to localize to centromeric DNA repeats to initiate heterochromatin assembly. These findings reveal a physical and functional link between Rdp1 and RITS and suggest that noncoding RNAs provide a platform for siRNA-dependent localization of RNAi complexes to specific chromosome regions. %G English %L inserm-00332373 %U https://inserm.hal.science/inserm-00332373 %~ INSERM