RNA editing of human microRNAs.
BACKGROUND
MicroRNAs (miRNAs) are short RNAs of around 22 nucleotides that regulate gene expression. The primary transcripts of miRNAs contain double-stranded RNA and are therefore potential substrates for adenosine to inosine (A-to-I) RNA editing.


RESULTS
We have conducted a survey of RNA editing of miRNAs from ten human tissues by sequence comparison of PCR products derived from matched genomic DNA and total cDNA from the same individual. Six out of 99 (6%) miRNA transcripts from which data were obtained were subject to A-to-I editing in at least one tissue. Four out of seven edited adenosines were in the mature miRNA and were predicted to change the target sites in 3' untranslated regions. For a further six miRNAs, we identified A-to-I editing of transcripts derived from the opposite strand of the genome to the annotated miRNA. These miRNAs may have been annotated to the wrong genomic strand.


CONCLUSIONS
Our results indicate that RNA editing increases the diversity of miRNAs and their targets, and hence may modulate miRNA function.
Blow
Matthew J
MJ
Cancer Genome Project, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA, UK.
Grocock
Russell J
RJ
van Dongen
Stijn
S
Enright
Anton J
AJ
Dicks
Ed
E
Futreal
P Andrew
PA
Wooster
Richard
R
Stratton
Michael R
MR
D000241:Adenosine / Q000378:metabolism; D006801:Humans; D007288:Inosine / Q000378:metabolism; D035683:MicroRNAs / Q000737:chemistry* / Q000378:metabolism*; D017393:RNA Editing; D012322:RNA Precursors / Q000737:chemistry / Q000378:metabolism; D012330:RNA, Double-Stranded / Q000737:chemistry / Q000378:metabolism
D035683:MicroRNAs; D012322:RNA Precursors; D012330:RNA, Double-Stranded; D007288:Inosine; D000241:Adenosine