Two RNAi complexes, RITS and RDRC, physically interact and localize to noncoding centromeric RNAs

Mohammad R Motamedi; André Verdel; Serafin U Colmenares; Scott A Gerber; Steven P Gygi; Danesh Moazed

doi:10.1016/j.cell.2004.11.034

Two RNAi complexes, RITS and RDRC, physically interact and localize to noncoding centromeric RNAs

Cell. 2004 Dec 17;119(6):789-802. doi: 10.1016/j.cell.2004.11.034.

Authors

Mohammad R Motamedi¹, André Verdel, Serafin U Colmenares, Scott A Gerber, Steven P Gygi, Danesh Moazed

Affiliation

¹ Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.

PMID: 15607976
DOI: 10.1016/j.cell.2004.11.034

Abstract

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.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S.

MeSH terms

Adenosine Triphosphatases / genetics
Adenosine Triphosphatases / metabolism*
Cell Cycle Proteins / genetics
Cell Cycle Proteins / metabolism
Cell Nucleus / genetics
Cell Nucleus / metabolism
Centromere / genetics
Centromere / metabolism*
Heterochromatin / genetics
Heterochromatin / metabolism*
Histone-Lysine N-Methyltransferase
Methyltransferases / genetics
Methyltransferases / metabolism
Protein Binding
RNA Helicases / genetics
RNA Helicases / metabolism
RNA, Fungal / genetics
RNA, Fungal / metabolism
RNA, Untranslated / genetics
RNA, Untranslated / metabolism
RNA-Induced Silencing Complex / genetics
RNA-Induced Silencing Complex / metabolism*
Ribonuclease III / genetics
Ribonuclease III / metabolism
Schizosaccharomyces / genetics
Schizosaccharomyces / metabolism
Schizosaccharomyces pombe Proteins / genetics
Schizosaccharomyces pombe Proteins / metabolism*

Substances

Cell Cycle Proteins
Heterochromatin
RNA, Fungal
RNA, Untranslated
RNA-Induced Silencing Complex
Schizosaccharomyces pombe Proteins
Methyltransferases
Histone-Lysine N-Methyltransferase
clr4 protein, S pombe
Ribonuclease III
Adenosine Triphosphatases
Rdp1 protein, S pombe
RNA Helicases