RevCen is a family of non-coding RNA found in Schizosaccharomyces. It is a megastructure containing several siRNA which use the RNAi pathway to regulate heterochromatin formation. The long RNA transcript forms a secondary structure with several stem-loops which are processed by dicer into siRNA. This siRNA then initiate the formation of heterochromatin at the centromeres of fission yeast.[1] Northern blot analysis confirmed the siRNAs were produced from the large RNA structure RevCen in vivo. As with all siRNAs, the enzyme dicer is responsible for dissecting dsRNA into the 21nt stretch of double-stranded RNA. Human recombinant dicer enzyme processed the RevCen structure in vitro, though the same activity by yeast Dcr1 has not been confirmed.[1]

RevCen
Conserved secondary structure of RevCen RNA.
Identifiers
SymbolRevCen
Other data
RNA typeGene; pre-miRNA
Domain(s)Schizosaccharomyces
PDB structuresPDBe

This is a different mechanism to that involving the well-understood RITS (RNA-induced initiation of transcriptional gene silencing) complex.[2][3] It has been suggested that both mechanisms work together, with the RevCen structure potentially acting as a backup system when Rdp1-generated double-stranded siRNA precursors are lost.[1]

References

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  1. ^ a b c Djupedal I, Kos-Braun IC, Mosher RA, et al. (December 2009). "Analysis of small RNA in fission yeast; centromeric siRNAs are potentially generated through a structured RNA". EMBO J. 28 (24): 3832–3844. doi:10.1038/emboj.2009.351. PMC 2797062. PMID 19942857.
  2. ^ Sugiyama T, Cam H, Verdel A, Moazed D, Grewal SI (January 2005). "RNA-dependent RNA polymerase is an essential component of a self-enforcing loop coupling heterochromatin assembly to siRNA production". Proc. Natl. Acad. Sci. U.S.A. 102 (1): 152–157. doi:10.1073/pnas.0407641102. PMC 544066. PMID 15615848.
  3. ^ Verdel A, Jia S, Gerber S, et al. (January 2004). "RNAi-mediated targeting of heterochromatin by the RITS complex". Science. 303 (5658): 672–676. doi:10.1126/science.1093686. PMC 3244756. PMID 14704433.

Further reading

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