RNA polymerase V functions in Arabidopsis interphase heterochromatin organization independently of the 24-nt siRNA-directed DNA methylation pathway.

ABSTRACT: In Arabidopsis, pericentromeric repeats, retroelements, and silenced rRNA genes are assembled into heterochromatin within nuclear structures known as chromocenters. The mechanisms governing higher-order heterochromatin organization are poorly understood but 24-nt small interfering RNAs (siRNAs) are known to play key roles in heterochromatin formation. Nuclear RNA polymerase IV (Pol IV), RNA-DEPENDENT RNA POLYMERASE 2 (RDR2), and DICER-LIKE 3 (DCL3) are required for biogenesis of 24-nt siRNAs that associate with ARGONAUTE 4 (AGO4). Nuclear RNA polymerase V (Pol V) collaborates with DRD1 (DEFICIENT IN RNA-DEPENDENT DNA METHYLATION 1) to generate transcripts at heterochromatic loci that are hypothesized to bind to siRNA-AGO4 complexes and subsequently recruit the de-novo DNA methylation and/o

SUBMITTER: Pontes O 

PROVIDER: S-EPMC2902898 | biostudies-literature | 2009 Jul

REPOSITORIES: biostudies-literature