RNA editing (also RNA modification) is a molecular process through which some cells can make discrete changes to specific nucleotide sequences within an RNA molecule after it has been generated by RNA polymerase. It occurs in all living organisms and is one of the most evolutionarily conserved properties of RNAs.

RNA editing may include the insertion, deletion, and base substitution of nucleotides within the RNA molecule. RNA editing is relatively rare, with common forms of RNA processing (e.g. splicing, 5′-capping, and 3′-polyadenylation) not usually considered as editing. It can affect the activity, localization as well as stability of RNAs, and has been linked with human diseases.

The diversity of RNA editing phenomena includes nucleobase modifications such as cytidine (C) to uridine (U) and adenosine (A) to inosine (I) deaminations, as well as non-template nucleotide additions and insertions. RNA editing in mRNAs effectively alters the amino acid sequence of the encoded protein so that it differs from that predicted by the genomic DNA sequence.

RNA editing – Wikipedia

In intestinal mucosal cells, an RNA editing complex alters one base in ApoB-100 mRNA (C is deaminated and converted to U), producing a stop codon. This leads to production of a protein that is only 48% of the original protein, the ApoB-48 of chylomicrons.

Deamination of adenine (A) in tRNA produces inosine (I), which helps identifying more than one codon (degeneracy of the code).

RNA-editing events may regulate cancer development and metabolic dysfunctions.

See the new post:

All You Need To know About RNA Editing