N(1)-methyladenine (m(1)A) and N(3)-methylcytosine (m(3)C) are major toxic and mutagenic lesions induced by alkylation in single-stranded DNA. In bacteria and mammals, m(1)A and m(3)C were recently shown to be repaired by AlkB-mediated oxidative demethylation, a direct DNA damage reversal mechanism. No AlkB gene homologues have been identified in Archaea. We report that m(1)A and m(3)C are repaired by the AfAlkA base excision repair glycosylase of Archaeoglobus fulgidus, suggesting a different repair mechanism for these lesions in the third domain of life. In addition, AfAlkA was found to effect a robust excision of 1,N(6)-ethenoadenine. We present a high-resolution crystal structure of AfAlkA, which, together with the characterization of several site-directed mutants, forms a molecular rationalization for the newly discovered base excision activity.
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http://dx.doi.org/10.1038/sj.emboj.7601662 | DOI Listing |
Mol Biol Rep
November 2024
Department of breast surgery, The First Affiliated Hospital with Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029, China.
Cell Commun Signal
October 2024
Department of Pharmacology, School of Pharmacy, Laboratory of Molecular Pharmacology, Southwest Medical University, Luzhou, Sichuan, 646000, China.
As the role of RNA modification in gene expression regulation and human diseases, the "epitranscriptome" has been shown to be an important player in regulating many physiological and pathological processes. Meanwhile, the phenomenon of cancer drug resistance is becoming more and more frequent, especially in the case of cancer chemotherapy resistance. In recent years, research on relationship between post-transcriptional modification and cancer including drug resistance has become a hot topic, especially the methylation of the sixth nitrogen site of RNA adenosine-mA (N6-methyladenosine).
View Article and Find Full Text PDFHeliyon
July 2024
Department of Gastroenterology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou 310009, China.
AlkB homolog 1 (ALKBH1) is a member of the AlkB family of dioxygenases that are dependent on Fe(II) and α-ketoglutarate. Mounting evidence demonstrates that ALKBH1 exhibits enzymatic activity against various substrates, including N6-methyladenosine (mA), N1-methyladenosine (mA), N3-methylcytidine (mC), 5-methylcytosine (mC), N6-methyladenine (N-mA, 6mA), and H2A, indicating its dual roles in different biological processes and involvement in human diseases. Up to the present, there is ongoing debate regarding ALKBH1's enzymatic activity.
View Article and Find Full Text PDFCell Prolif
September 2024
Department of General Surgery, Xiangya Hospital, Central South University, Changsha, Hunan, China.
High-throughput sequencing has sparked increased research interest in RNA modifications, particularly tRNA methylation, and its connection to various diseases. However, the precise mechanisms underpinning the development of these diseases remain largely elusive. This review sheds light on the roles of several tRNA methylations (m1A, m3C, m5C, m1G, m2G, m7G, m5U, and Nm) in diverse biological functions, including metabolic processing, stability, protein interactions, and mitochondrial activities.
View Article and Find Full Text PDFMol Cancer
June 2024
Department of Pathology, Xiangya Hospital, Central South University, Changsha, Hunan, China.
RNA methylation, a prevalent post-transcriptional modification, has garnered considerable attention in research circles. It exerts regulatory control over diverse biological functions by modulating RNA splicing, translation, transport, and stability. Notably, studies have illuminated the substantial impact of RNA methylation on tumor immunity.
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