A-to-I editing of coding and non-coding RNAs by ADARs

Abstract

Adenosine deaminases acting on RNA (ADARs) convert adenosine to inosine in double-stranded RNA. This A-to-I editing occurs not only in protein-coding regions of mRNAs, but also frequently in non-coding regions that contain inverted Alu repeats. Editing of coding sequences can result in the expression of functionally altered proteins that are not encoded in the genome, whereas the significance of Alu editing remains largely unknown. Certain microRNA (miRNA) precursors are also edited, leading to reduced expression or altered function of mature miRNAs. Conversely, recent studies indicate that ADAR1 forms a complex with Dicer to promote miRNA processing, revealing a new function of ADAR1 in the regulation of RNA interference.

Aging and Alzheimer’s disease: Comparison and associations from molecular to system level

“…RNA editing is the conversion of adenosine to inosine in double‐stranded RNA by adenosine deaminases acting on RNA (ADARs) (Nishikura, 2016). In C. elegans , the RNA editomes of wild‐type and ADAR mutants were profiled.…”

Unveiling the non-repair face of the Base Excision Repair pathway in RNA processing: A missing link between DNA repair and gene expression?

“…Adenosine to inosine (A-to-I) RNA-editing within the hairpin region of miRNA precursors is among the major effective mechanism described to alter the primary sequence of RNA. A-to-I miRNA editing is mediated by adenosine deaminases acting on RNA (ADAR) protein, ADAR1 and ADAR2, having consequences in miRNA biogenesis both at the level of Drosha and Dicer [100]. Recently, Wang et al demonstrated that also oxidation represents another miRNA post-transcriptional modification with remarkably pathological outcomes.…”

Profiling of m6A RNA modifications identified an age‐associated regulation of AGO2 mRNA stability

“…Regulatory RNA modifications include A‐to‐I editing, pseudouridylation, methylation, and nicotinamide‐adenine dinucleotide (NAD + ) capping, which can regulate many cellular processes by influencing RNA metabolism (Jiao et al., 2017; Nishikura, 2016; Walters et al., 2016; Wang et al., 2014; Zhao, Roundtree & He, 2017). For example, A‐to‐I editing within a coding region of mRNA may lead to abnormal protein expressions that are not encoded in the genome, and editing within intronic regions could create new splice sites resulting in the inclusion of an undesired sequence in the mature mRNA (Nishikura, 2016).…”

“…For example, A‐to‐I editing within a coding region of mRNA may lead to abnormal protein expressions that are not encoded in the genome, and editing within intronic regions could create new splice sites resulting in the inclusion of an undesired sequence in the mature mRNA (Nishikura, 2016). Also, hundreds of pseudouridylated mRNAs were found in mammalian cells and, in response to serum starvation, dynamic changes of pseudouridylation were observed, underscoring its potential as a regulatory element (Carlile et al., 2014).…”