A mitochondrial cytidine deaminase is responsible for C to U editing of tRNA(Trp) to decode the UGA codon in Trypanosoma brucei

0554452 - BC 2022 RIV US eng J - Journal Article
Paris, Zdeněk - Svobodová, Michaela - Kachale, Ambar - Horáková, Eva - Nenarokova, Anna - Lukeš, Julius
A mitochondrial cytidine deaminase is responsible for C to U editing of tRNA(Trp) to decode the UGA codon in Trypanosoma brucei.
RNA biology. Roč. 18, JUL 2021 (2021), s. 278-286. ISSN 1547-6286. E-ISSN 1555-8584
R&D Projects: GA ČR(CZ) GA20-11585S; GA ČR(CZ) GA18-15962S; GA MŠMT(CZ) LL1601; GA MŠMT(CZ) EF16_019/0000759; GA ČR(CZ) GA20-07186S
Institutional support: RVO:60077344
Keywords : transfer-rna import * leishmania-tarentolae * adenosine-deaminase * protein-synthesis * anticodon * translation * identification * thiolation * stability * inosine * Mitochondrion * tryptophanyl tRNA * editing * cytidine deaminase * trypanosoma
OECD category: Parasitology
Impact factor: 4.766, year: 2021
Method of publishing: Open access
https://www.tandfonline.com/doi/full/10.1080/15476286.2021.1940445

In kinetoplastid protists, all mitochondrial tRNAs are encoded in the nucleus and imported from the cytoplasm to maintain organellar translation. This also applies to the tryptophanyl tRNA (tRNA(Trp)) encoded by a single-copy nuclear gene, with a CCA anticodon to read UGG codon used in the cytosolic translation. Yet, in the mitochondrion it is unable to decode the UGA codon specifying tryptophan. Following mitochondrial import of tRNA(Trp), this problem is solved at the RNA level by a single C34 to U34 editing event that creates the UCA anticodon, recognizing UGA. To identify the enzyme responsible for this critical editing activity, we scrutinized the genome of Trypanosoma brucei for putative cytidine deaminases as the most likely candidates. Using RNAi silencing and poisoned primer extension, we have identified a novel deaminase enzyme, named here TbmCDAT for mitochondrial Cytidine Deaminase Acting on tRNA, which is responsible for this organelle-specific activity in T. brucei. The ablation of TbmCDAT led to the downregulation of mitochondrial protein synthesis, supporting its role in decoding the UGA tryptophan codon.
Permanent Link: http://hdl.handle.net/11104/0329160