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Thalalla Gamage S, Howpay Manage SA, Chu TT, Meier JL. Cytidine Acetylation Across the Tree of Life. Acc Chem Res 2024; 57:338-348. [PMID: 38226431 DOI: 10.1021/acs.accounts.3c00673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2024]
Abstract
Acetylation plays a critical role in regulating eukaryotic transcription via the modification of histones. Beyond this well-documented function, a less explored biological frontier is the potential for acetylation to modify and regulate the function of RNA molecules themselves. N4-Acetylcytdine (ac4C) is a minor RNA nucleobase conserved across all three domains of life (archaea, bacteria, and eukarya), a conservation that suggests a fundamental role in biological processes. Unlike many RNA modifications that are controlled by large enzyme families, almost all organisms catalyze ac4C using a homologue of human Nat10, an essential disease-associated acetyltransferase enzyme.A critical step in defining the fundamental functions of RNA modifications has been the development of methods for their sensitive and specific detection. This Account describes recent progress enabling the use of chemical sequencing reactions to map and quantify ac4C with single-nucleotide resolution in RNA. To orient readers, we first provide historical background of the discovery of ac4C and the enzymes that catalyze its formation. Next, we describe mechanistic experiments that led to the development of first- and second-generation sequencing reactions able to determine ac4C's position in a polynucleotide by exploiting the nucleobase's selective susceptibility to reduction by hydride donors. A notable feature of this chemistry, which may serve as a prototype for nucleotide resolution RNA modification sequencing reactions more broadly, is its ability to drive a penetrant and detectable gain of signal specifically at ac4C sites. Emphasizing practical applications, we present how this optimized chemistry can be integrated into experimental workflows capable of sensitive, transcriptome-wide analysis. Such readouts can be applied to quantitatively define the ac4C landscape across the tree of life. For example, in human cell lines and yeast, this method has uncovered that ac4C is highly selective, predominantly occupying dominant sites within rRNA (rRNA) and tRNA (tRNA). By contrast, when we extend these analyses to thermophilic archaea they identify the potential for much more prevalent patterns of cytidine acetylation, leading to the discovery of a role for this modification in adaptation to environmental stress. Nucleotide resolution analyses of ac4C have also allowed for the determination of structure-activity relationships required for short nucleolar RNA (snoRNA)-catalyzed ac4C deposition and the discovery of organisms with unexpectedly divergent tRNA and rRNA acetylation signatures. Finally, we share how these studies have shaped our approach to evaluating novel ac4C sites reported in the literature and highlight unanswered questions and new directions that set the stage for future research in the field.
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Affiliation(s)
- Supuni Thalalla Gamage
- Chemical Biology Laboratory, National Cancer Institute, National Institutes of Health, Frederick, Maryland 21702, United States
| | - Shereen A Howpay Manage
- Chemical Biology Laboratory, National Cancer Institute, National Institutes of Health, Frederick, Maryland 21702, United States
| | - T Thu Chu
- Chemical Biology Laboratory, National Cancer Institute, National Institutes of Health, Frederick, Maryland 21702, United States
| | - Jordan L Meier
- Chemical Biology Laboratory, National Cancer Institute, National Institutes of Health, Frederick, Maryland 21702, United States
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Perez M, Nance KD, Bak DW, Gamage ST, Najera SS, Conte AN, Linehan WM, Weerapana E, Meier JL. Conditional Covalent Lethality Driven by Oncometabolite Accumulation. ACS Chem Biol 2022; 17:2789-2800. [PMID: 36190452 PMCID: PMC10612128 DOI: 10.1021/acschembio.2c00384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) is a cancer predisposition syndrome driven by mutation of the tumor suppressor fumarate hydratase (FH). Inactivation of FH causes accumulation of the electrophilic oncometabolite fumarate. In the absence of methods for reactivation, tumor suppressors can be targeted via identification of synthetic lethal interactions using genetic screens. Inspired by recent advances in chemoproteomic target identification, here, we test the hypothesis that the electrophilicity of the HLRCC metabolome may produce unique susceptibilities to covalent small molecules, a phenomenon we term conditional covalent lethality. Screening a panel of chemically diverse electrophiles, we identified a covalent ligand, MP-1, that exhibits FH-dependent cytotoxicity. Synthesis and structure-activity profiling identified key molecular determinants underlying the molecule's effects. Chemoproteomic profiling of cysteine reactivity together with clickable probes validated the ability of MP-1 to engage an array of functional cysteines, including one lying in the Zn-finger domain of the tRNA methyltransferase enzyme TRMT1. TRMT1 overexpression rescues tRNA methylation from inhibition by MP-1 and partially attenuates the covalent ligand's cytotoxicity. Our studies highlight the potential for covalent metabolites and small molecules to synergistically produce novel synthetic lethal interactions and raise the possibility of applying phenotypic screening with chemoproteomic target identification to identify new functional oncometabolite targets.
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Affiliation(s)
- Minervo Perez
- Chemical Biology Laboratory, National Cancer Institute, Frederick, Maryland, 21072, USA
| | - Kellie D. Nance
- Chemical Biology Laboratory, National Cancer Institute, Frederick, Maryland, 21072, USA
| | - Daniel W. Bak
- Department of Chemistry, Boston College, Chestnut Hill, Massachusetts, 02467, USA
| | | | - Susana S. Najera
- Chemical Biology Laboratory, National Cancer Institute, Frederick, Maryland, 21072, USA
- Urologic Oncology Branch, National Cancer Institute, Bethesda, Maryland, 20892, USA
| | - Amy N. Conte
- Chemical Biology Laboratory, National Cancer Institute, Frederick, Maryland, 21072, USA
| | - W. Marston Linehan
- Urologic Oncology Branch, National Cancer Institute, Bethesda, Maryland, 20892, USA
| | - Eranthie Weerapana
- Department of Chemistry, Boston College, Chestnut Hill, Massachusetts, 02467, USA
| | - Jordan L. Meier
- Chemical Biology Laboratory, National Cancer Institute, Frederick, Maryland, 21072, USA
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