The process of RNA editing leads to sequence changes that are not reflective of the genetic information contained within the gene for an edited RNA. RNA editing occurs through the action of specific nucleotide deaminases that change either adenine to inosine or cytidine to uridine. These nucleotide changes can affect the coding or splicing capacity of the RNA. Which of the following proteins is an important example of the result of RNA editing?
A) apo-B48
B) calcitonin gene related peptide (CGRP)
C) ferritin
D) glutamate dehydrogenase
E) tissue factor (factor III)

Question

Quizplus · Accepted Answer

Apo-B48 is an important example of RNA editing, where a cytidine to uridine change creates a stop codon, resulting in a truncated protein compared to apo-B100. RNA editing in mammals involves the deamination of adenine (A) to produce inosine (I) in pre-mRNAs. The process of A to I editing is catalyzed by ADARs (ADAs acting on RNA). In some pre-mRNAs this alters splicing; in some it alters codon(s). RNA editing also occurs to convert C to U. A C-to-U edit in the gene for apolipoprotein B leads to tissue-specific generation of apoB- 48 in intestines, whereas, the nonedited mRNA makes apoB-100 in liver.

The Process of RNA Editing Leads to Sequence Changes That