This family of proteins are eukaryotic RNA dependent RNA polymerases. These proteins are involved in post transcriptional gene silencing where they are thought to amplify dsRNA templates.
This entry represents various eukaryotic RNA-dependent RNA polymerases (RDRP; EC), such as RCRP-1, RDRP-2 and RDRP-6. These enzymes are involved in the amplification of regulatory microRNAs during post-transcriptional gene silencing [PUBMED:12553882]; they are also required for transcriptional gene silencing. Double-stranded RNA has been shown to induce gene silencing in diverse eukaryotes and by a variety of pathways [PUBMED:16691418]. These enzymes also play a role in the RNA interference (RNAi) pathway, which is important for heterochromatin formation, accurate chromosome segregation, centromere cohesion and telomere function during mitosis and meiosis. RDRP enzymes are highly conserved in most eukaryotes, but are missing in archaea and bacteria. The core catalytic domain of RDRP enzymes is structurally similar to the beta' subunit of DNA-dependent RNA polymerases (DDRP), however the other domains of DDRP show no similarity to those of RDRP.
Sijen T, Fleenor J, Simmer F, Thijssen KL, Parrish S, Timmons L, Plasterk RH, Fire A; , Cell 2001;107:465-476.: On the role of RNA amplification in dsRNA-triggered gene silencing. PUBMED:11719187 EPMC:11719187 .
Dalmay T, Hamilton A, Rudd S, Angell S, Baulcombe DC; , Cell 2000;101:543-553.: An RNA-dependent RNA polymerase gene in Arabidopsis is required for posttranscriptional gene silencing mediated by a transgene but not by a virus. PUBMED:10850496 EPMC:10850496 .
Iyer LM, Koonin EV, Aravind L;, BMC Struct Biol. 2003;3:1.: Evolutionary connection between the catalytic subunits of DNA-dependent RNA polymerases and eukaryotic RNA-dependent RNA polymerases and the origin of RNA polymerases. PUBMED:12553882 EPMC:12553882.