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Li H, Zhu D, Yang Y, Ma Y, Chen Y, Xue P, Chen J, Qin M, Xu D, Cai C, Cheng H. Restricted tRNA methylation by intermolecular disulfide bonds in DNMT2/TRDMT1. Int J Biol Macromol 2023; 251:126310. [PMID: 37579906 DOI: 10.1016/j.ijbiomac.2023.126310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 08/09/2023] [Accepted: 08/10/2023] [Indexed: 08/16/2023]
Abstract
Reportedly, DNMT2/TRDMT1 mainly methylates tRNAs at C38 and prevents them from the cleavage under stress. It also plays an essential role in the survival and physiological homeostasis of organisms. Nevertheless, DNMT2/TRDMT1 exhibits much weaker tRNA methylation activity in vitro than other tRNA methyltransferases, TrmD and Trm5. Here, we explored the restricted tRNA methylation mechanism by DNMT2/TRDMT1. In the current study, the optimized buffer C at 37 °C was the best condition for DNMT2/TRDMT1 activation. Of note, Dithiothreitol (DTT) was an indispensable component for this enzyme catalysis. Moreover, reductants took similar effects on the conformation change and oligomeric formation of DNMT2/TRDMT1. Ultimately, LC-MS/MS result revealed that C292-C292 and C292-C287 were predominant intermolecular disulfide bonds in recombinant DNMT2/TRDMT1. Notably, DNMT2/TRDMT1 existed primarily as dimers via intermolecular disulfide bonds C79-C24, C292-C292, and C222-C24 in HEK293T cells. GSSG stress enhanced tRNA methylation level in the early stage of stress, whereas the DNMT2/TRDMT1 activity might be unfavorable along with this enzyme accumulation in the nucleus. Excitingly, GSH stress downregulated the DNMT2/TRDMT1 expression and promoted tRNA methylation in cells, probably through breaking intermolecular disulfide bonds in this enzyme. Thus, our findings demonstrated restricted tRNA methylation by disulfide bonds in DNMT2/TRDMT1, and will provide important implications for redox stress related-diseases.
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Affiliation(s)
- Huari Li
- College of Veterinary Medicine, Huazhong Agricultural University, No.1 Shizishan Street, Wuhan 430070, Hubei, China.
| | - Daiyun Zhu
- College of Veterinary Medicine, Huazhong Agricultural University, No.1 Shizishan Street, Wuhan 430070, Hubei, China
| | - Yapeng Yang
- College of Veterinary Medicine, Huazhong Agricultural University, No.1 Shizishan Street, Wuhan 430070, Hubei, China
| | - Yunfei Ma
- College of Veterinary Medicine, Huazhong Agricultural University, No.1 Shizishan Street, Wuhan 430070, Hubei, China
| | - Yong Chen
- College of Veterinary Medicine, Huazhong Agricultural University, No.1 Shizishan Street, Wuhan 430070, Hubei, China
| | - Pingfang Xue
- College of Veterinary Medicine, Huazhong Agricultural University, No.1 Shizishan Street, Wuhan 430070, Hubei, China
| | - Juan Chen
- College of Veterinary Medicine, Huazhong Agricultural University, No.1 Shizishan Street, Wuhan 430070, Hubei, China
| | - Mian Qin
- College of Veterinary Medicine, Huazhong Agricultural University, No.1 Shizishan Street, Wuhan 430070, Hubei, China
| | - Dandan Xu
- College of Veterinary Medicine, Huazhong Agricultural University, No.1 Shizishan Street, Wuhan 430070, Hubei, China
| | - Chao Cai
- College of Veterinary Medicine, Huazhong Agricultural University, No.1 Shizishan Street, Wuhan 430070, Hubei, China
| | - Hongjing Cheng
- College of Veterinary Medicine, Huazhong Agricultural University, No.1 Shizishan Street, Wuhan 430070, Hubei, China
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Sałamaszyńska-Guz A, Rasmussen PK, Murawska M, Douthwaite S. Campylobacter jejuni Virulence Factors Identified by Modulating Their Synthesis on Ribosomes With Altered rRNA Methylation. Front Cell Infect Microbiol 2022; 11:803730. [PMID: 35096652 PMCID: PMC8794745 DOI: 10.3389/fcimb.2021.803730] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 12/17/2021] [Indexed: 12/02/2022] Open
Abstract
Campylobacter jejuni is a major cause of food poisoning worldwide, and remains the main infective agent in gastroenteritis and related intestinal disorders in Europe and the USA. As with all bacterial infections, the stages of adhesion to host tissue, survival in the host and eliciting disease all require the synthesis of proteinaceous virulence factors on the ribosomes of the pathogen. Here, we describe how C. jejuni virulence is attenuated by altering the methylation of its ribosomes to disrupt the composition of its proteome, and how this in turn provides a means of identifying factors that are essential for infection and pathogenesis. Specifically, inactivation of the C. jejuni Cj0588/TlyA methyltransferase prevents methylation of nucleotide C1920 in the 23S rRNA of its ribosomes and reduces the pathogen’s ability to form biofilms, to attach, invade and survive in host cells, and to provoke the innate immune response. Mass spectrometric analyses of C. jejuni TlyA-minus strains revealed an array of subtle changes in the proteome composition. These included reduced amounts of the cytolethal distending toxin (CdtC) and the MlaEFD proteins connected with outer membrane vesicle (OMV) production. Inactivation of the cdtC and mlaEFD genes confirmed the importance of their encoded proteins in establishing infection. Collectively, the data identify a subset of genes required for the onset of human campylobacteriosis, and serve as a proof of principle for use of this approach in detecting proteins involved in bacterial pathogenesis.
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Affiliation(s)
- Agnieszka Sałamaszyńska-Guz
- Division of Microbiology, Department of Pre-Clinical Sciences, Institute of Veterinary Medicine, Warsaw University of Life Sciences – SGGW, Warsaw, Poland
- *Correspondence: Agnieszka Sałamaszyńska-Guz, ; Stephen Douthwaite,
| | | | - Małgorzata Murawska
- Division of Microbiology, Department of Pre-Clinical Sciences, Institute of Veterinary Medicine, Warsaw University of Life Sciences – SGGW, Warsaw, Poland
| | - Stephen Douthwaite
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
- *Correspondence: Agnieszka Sałamaszyńska-Guz, ; Stephen Douthwaite,
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