Expressional Localization And Functionally Identifying An Rna Editing Enzyme Bmadara Of The Silkwormbombyx Mori

Simple Summary Adenosine deaminase acting on RNA (ADAR) is a key enzyme in the editing of adenosine into inosine (A-to-I). The loss or dysfunction of ADAR enzymes in higher eukaryotes affects the editing efficiency of target genes, leading to some neurological diseases. The silkwormBombyx moriis an oligophagous economically important insect and has been used as an important lepidoptera model insect. By far, the knowledge about A-to-I RNA editing and ADAR members inB. mori(BmADAR) is very limited. In this paper, we present a first molecular comprehensive cloning, sequence analysis of BmADAR transcripts and subcelluar localization of BmADARa. As a result, we obtained six BmADAR transcripts encoding different amino and carboxyl termini, among whichBmADARais a mainly expressed transcript with complete open reading frame. Our further investigations showed that the majority of BmADARa protein exists in the nucleus and has editing function to a specific site of the silkwormsynaptotagmin Igene. Overall, by molecular cloning and functional identifing, this paper introduces the first ADAR enzyme inB. moriand contributes to further exploration of the functional domain of BmADARa and its editing substrates and target sites. The most common type of RNA editing in metazoans is the deamination of adenosine into inosine (A-to-I) catalyzed by the adenosine deaminase acting on the RNA (ADAR) family of proteins. The deletion or dysfunction of ADAR enzymes in higher eukaryotes can affect the efficiency of substrate editing and cause neurological disorders. However, the information concerning A-to-I RNA editing and ADAR members in the silkworm,Bombyx mori(BmADAR), is limited. In this study, a first molecular comprehensive cloning and sequence analysis ofBmADARtranscripts was presented. A complete open reading frame (ORF) (BmADARa) was obtained using RT-PCR and RACE and its expression pattern, subcellular localization and A-to-I RNA-editing function on the silkwormsynaptotagmin I(BmSyt I) were investigated. Subcellular localization analysis observed thatBmADARawas mainly localized in the nucleus. To further study the A-to-I RNA-editing function ofBmADARa, BmSyt I-pIZ-EGFP was constructed and co-transfected with BmADARa-pIZ-EGFP into BmN cells. The result demonstrates that BmADARa can functionally edit the specific site ofBmSyt I.Taken together, this study not only provides insight into the function of the first ADAR enzyme inB. mori, but also lays foundations for further exploration of the functional domain of BmADARa and its editing substrates and target sites.