RNA Polymerase IV Directs Silencing of Endogenous DNA
Abstract
Plants encode subunits for a fourth RNA polymerase (Pol IV) in addition to the well-known DNA-dependent RNA polymerases I, II, and III. By mutation of the two largest subunits (NRPD1a and NRPD2), we show that Pol IV silences certain transposons and repetitive DNA in a short interfering RNA pathway involving RNA-dependent RNA polymerase 2 and Dicer-like 3. The existence of this distinct silencing polymerase may explain the paradoxical involvement of an RNA silencing pathway in maintenance of transcriptional silencing.
- Publication:
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Science
- Pub Date:
- April 2005
- DOI:
- 10.1126/science.1106910
- Bibcode:
- 2005Sci...308..118H
- Keywords:
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- MOLEC BIO