Small interfering RNA
Small interfering RNA (siRNA) [1] is a class of double-stranded RNA molecules, 20-25 base pairs long.
siRNA plays many roles, but it is most notable in the RNA interference (RNAi) pathway,[2] where it interferes with the expression of certain genes. Genes are only affected if they have nucleotide sequences complementary to those of the siRNA.
siRNA functions by breaking down mRNA after transcription.[3] This prevents translation of the gene into protein. siRNA also acts in RNAi-related pathways, e.g., as an antiviral mechanism or in shaping the chromatin structure of a genome. The complexity of these pathways is only now being worked out.
Small Interfering RNA Media
SVG schematic of siRNA structure
siRNA mechanism
Dicer protein colored by protein domain.
A simplified version of the Ping-Pong Method, involving proteins Aubergine (Aub) and Argonaute-3 (Ago3) cleaving the 3' and 5' ends of piRNA.
The generalised RNAi mechanism upto the molecular level depicting the role of various cellular proteins and external siRNAs.
References
- ↑ sometimes known as short interfering RNA or silencing RNA
- ↑ Hannon G.J. & Rossi J.J. 2004. Unlocking the potential of the human genome with RNA interference. Nature 431 (7006): 371–378. [1]
- ↑ RNA Interference: biology, mechanism, and applications