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Crane AB, Jetti SK, Littleton JT. A stochastic RNA editing process targets a limited number of sites in individual Drosophila glutamatergic motoneurons. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.17.594696. [PMID: 38798345 PMCID: PMC11118563 DOI: 10.1101/2024.05.17.594696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
RNA editing is a post-transcriptional source of protein diversity and occurs across the animal kingdom. Given the complete profile of mRNA targets and their editing rate in individual cells is unclear, we analyzed single cell RNA transcriptomes from Drosophila larval tonic and phasic glutamatergic motoneuron subtypes to determine the most highly edited targets and identify cell-type specific editing. From ∼15,000 genes encoded in the genome, 316 high confidence A-to-I canonical RNA edit sites were identified, with 102 causing missense amino acid changes in proteins regulating membrane excitability, synaptic transmission, and cellular function. Some sites showed 100% editing in single neurons as observed with mRNAs encoding mammalian AMPA receptors. However, most sites were edited at lower levels and generated variable expression of edited and unedited mRNAs within individual neurons. Together, these data provide insights into how the RNA editing landscape alters protein function to modulate the properties of two well-characterized neuronal populations in Drosophila .
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Li J, Fan G, Sakari M, Tsukahara T. Improvement of C-to-U RNA editing using an artificial MS2-APOBEC system. Biotechnol J 2024; 19:e2300321. [PMID: 38010373 DOI: 10.1002/biot.202300321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 11/20/2023] [Accepted: 11/22/2023] [Indexed: 11/29/2023]
Abstract
RNA cytidine deamination (C-to-U editing) has been achieved using the MS2-apolipoprotein B-editing catalytic polypeptide-like (APOBEC)1 editing system. Here, we fused the cytidine deaminase (CDA) enzymes APOBEC3A and APOBEC3G with the MS2 system and examined their RNA editing efficiencies in transfected HEK 293T cells. Given the single-stranded RNA preferences of APOBEC3A and APOBEC3G, we designed unconventional guide RNAs that induced a loop at the target sequence, allowing the target to form a single-stranded structure. Because APOBEC3A and APOBEC3G have different base preferences (5'-TC and 5'-CC, respectively), we introduced the D317W mutation into APOBEC3G to convert its base preference to that of APOBEC3A. Upon co-transfection with a guide RNA that induced the formation of a 14 nt loop on the target sequence, MS2-fused APOBEC3A and APOBEC3G showed high editing efficiency. While the D317W mutation of APOBEC3G led to a slight improvement in editing efficiency, the difference was not statistically significant. These findings indicate that APOBEC3A and APOBEC3G can induce C-to-U RNA editing when transfected with a loop guide RNA. Moreover, the editing efficiency of APOBEC3G can be enhanced by site-specific mutation to alter the base preference. Overall, our results demonstrate that the MS2 system can fuse and catalyze reactions with different enzymes, suggesting that it holds an even greater potential for RNA editing than is utilized currently.
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Affiliation(s)
- Jiarui Li
- Bioscience, Biotechnology and Biomedical Engineering Research Area, Japan Advanced Institute of Science and Technology, Nomi, Ishikawa, Japan
| | - Guangyao Fan
- Bioscience, Biotechnology and Biomedical Engineering Research Area, Japan Advanced Institute of Science and Technology, Nomi, Ishikawa, Japan
- School of Medicine, Shaoxing University, Shaoxing, China
| | - Matomo Sakari
- Bioscience, Biotechnology and Biomedical Engineering Research Area, Japan Advanced Institute of Science and Technology, Nomi, Ishikawa, Japan
| | - Toshifumi Tsukahara
- Bioscience, Biotechnology and Biomedical Engineering Research Area, Japan Advanced Institute of Science and Technology, Nomi, Ishikawa, Japan
- GeCoRT Co. Ltd., Nishi-ku, Yokohama, Japan
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Gao Z, Jiang W, Zhang Y, Zhang L, Yi M, Wang H, Ma Z, Qu B, Ji X, Long H, Zhang S. Amphioxus adenosine-to-inosine tRNA-editing enzyme that can perform C-to-U and A-to-I deamination of DNA. Commun Biol 2023; 6:744. [PMID: 37464027 PMCID: PMC10354150 DOI: 10.1038/s42003-023-05134-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 07/11/2023] [Indexed: 07/20/2023] Open
Abstract
Adenosine-to-inosine tRNA-editing enzyme has been identified for more than two decades, but the study on its DNA editing activity is rather scarce. We show that amphioxus (Branchiostoma japonicum) ADAT2 (BjADAT2) contains the active site 'HxE-PCxxC' and the key residues for target-base-binding, and amphioxus ADAT3 (BjADAT3) harbors both the N-terminal positively charged region and the C-terminal pseudo-catalytic domain important for recognition of substrates. The sequencing of BjADAT2-transformed Escherichia coli genome suggests that BjADAT2 has the potential to target E. coli DNA and can deaminate at TCG and GAA sites in the E. coli genome. Biochemical analyses further demonstrate that BjADAT2, in complex with BjADAT3, can perform A-to-I editing of tRNA and convert C-to-U and A-to-I deamination of DNA. We also show that BjADAT2 preferentially deaminates adenosines and cytidines in the loop of DNA hairpin structures of substrates, and BjADAT3 also affects the type of DNA substrate targeted by BjADAT2. Finally, we find that C89, N113, C148 and Y156 play critical roles in the DNA editing activity of BjADAT2. Collectively, our study indicates that BjADAT2/3 is the sole naturally occurring deaminase with both tRNA and DNA editing capacity identified so far in Metazoa.
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Affiliation(s)
- Zhan Gao
- Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, 266003, Qingdao, China.
| | - Wanyue Jiang
- Institute of Evolution & Marine Biodiversity, KLMME, Ocean University of China, 266003, Qingdao, China
| | - Yu Zhang
- Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, 266003, Qingdao, China
| | - Liping Zhang
- Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, 266003, Qingdao, China
| | - Mengmeng Yi
- Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, 266003, Qingdao, China
| | - Haitao Wang
- Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, 266003, Qingdao, China
| | - Zengyu Ma
- Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, 266003, Qingdao, China
| | - Baozhen Qu
- Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, 266003, Qingdao, China
| | - Xiaohan Ji
- Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, 266003, Qingdao, China
| | - Hongan Long
- Institute of Evolution & Marine Biodiversity, KLMME, Ocean University of China, 266003, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Laoshan Laboratory, 266237, Qingdao, China
| | - Shicui Zhang
- Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, 266003, Qingdao, China.
- Laboratory for Marine Biology and Biotechnology, Laoshan Laboratory, 266237, Qingdao, China.
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