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Bollu A, Schepers H, Klöcker N, Erguven M, Lawrence-Dörner AM, Rentmeister A. Visible Light Activates Coumarin-Caged mRNA for Cytoplasmic Cap Methylation in Cells. Chemistry 2024; 30:e202303174. [PMID: 37883670 DOI: 10.1002/chem.202303174] [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: 10/17/2023] [Accepted: 10/23/2023] [Indexed: 10/28/2023]
Abstract
Protein synthesis is important and regulated by various mechanisms in the cell. Translation initiation in eukaryotes starts at the 5' cap and is the most complex of the three phases of mRNA translation. It requires methylation of the N7 position of the terminal guanosine (m7 G). The canonical capping occurs in the nucleus, however, cytoplasmic recapping has been discovered. It functions in switching mRNAs between translating and non-translating states, but the individual steps are difficult to dissect. We targeted cytoplasmic cap methylation as the ultimate step of cytoplasmic recapping. We present an N7G photocaged 5' cap that can be activated for cytoplasmic methylation by visible light. We report chemical and chemo-enzymatic synthesis of this 5' cap with 7-(diethylamino)-4-methyl-coumarin (DEACM) at the N7G and validate that it is not bound by translation initiation factor 4E (eIF4E). We demonstrate incorporation into mRNA, the release of unmethylated cap analog and enzymatic remethylation to functional cap 0 after irradiation at 450 nm. In cells, irradiation triggers translation of mRNAs with the N7G photocaged 5' cap via cytoplasmic cap methylation.
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Affiliation(s)
- Amarnath Bollu
- Department of Chemistry, Institute of Biochemistry, University of Münster, Corrensstraße 36, 48149, Münster, Germany
| | - Helena Schepers
- Department of Chemistry, Institute of Biochemistry, University of Münster, Corrensstraße 36, 48149, Münster, Germany
| | - Nils Klöcker
- Department of Chemistry, Institute of Biochemistry, University of Münster, Corrensstraße 36, 48149, Münster, Germany
| | - Mehmet Erguven
- Department of Chemistry, Institute of Biochemistry, University of Münster, Corrensstraße 36, 48149, Münster, Germany
- Cells in Motion Interfaculty Centre, University of Münster, Waldeyerstraße 15, 48149, Münster, Germany
| | - Ann-Marie Lawrence-Dörner
- Department of Chemistry, Institute of Biochemistry, University of Münster, Corrensstraße 36, 48149, Münster, Germany
| | - Andrea Rentmeister
- Department of Chemistry, Institute of Biochemistry, University of Münster, Corrensstraße 36, 48149, Münster, Germany
- Cells in Motion Interfaculty Centre, University of Münster, Waldeyerstraße 15, 48149, Münster, Germany
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Abdellaoui C, Hermanns V, Reinfelds M, Scheurer M, Dreuw A, Heckel A, Wachtveitl J. A long-lived fluorenyl cation: efficiency booster for uncaging and photobase properties. Phys Chem Chem Phys 2022; 24:5294-5300. [PMID: 35174833 DOI: 10.1039/d1cp05292f] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The photochemistry of fluorenols has been of special interest for many years. This is because both the fluorenol and the fluorenyl cation are antiaromatic in the ground state due to their 4n π-electrons according to the Hückel rule. The photolysis reaction of various fluorene derivatives takes place via a cation intermediate and is preferred due to its excited state aromaticity. Here we present an extremely long-lived fluorenyl cation and its effects on the uncaging of various leaving groups. We analyze the relationship between uncaging quantum yields of fluorene-based cages and the longevity of their fluorenyl cations with different spectroscopic methods in the steady state and on an ultrafast time scale and find that the uncaging quantum yield rises with the stability of the cation. In contrast to previous reports, the cation can be observed on a time scale of minutes, even in moderately protic solvents as methanol and ethanol. The stability of this cation depends on the dimethylamino-substituents on the fluorene scaffold and the properties of the solvent. In addition, with bis-dimethylamino fluorenol, a photobase is introduced that expands the small group of known photoinduced hydroxide emitters.
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Affiliation(s)
- Chahinez Abdellaoui
- Institute of Physical and Theoretical Chemistry, Goethe-University Frankfurt, Frankfurt am Main 60438, Germany.
| | - Volker Hermanns
- Institute of Organic Chemistry, Goethe-University Frankfurt, Frankfurt am Main 60438, Germany.
| | - Matiss Reinfelds
- Institute of Organic Chemistry, Goethe-University Frankfurt, Frankfurt am Main 60438, Germany. .,Institute of Chemistry and Technology of Materials (ICTM), NAWI Graz, Graz University of Technology, Graz 8010, Austria.
| | - Maximilian Scheurer
- Interdisciplinary Center for Scientific Computing, Heidelberg University, Heidelberg 69120, Germany.
| | - Andreas Dreuw
- Interdisciplinary Center for Scientific Computing, Heidelberg University, Heidelberg 69120, Germany.
| | - Alexander Heckel
- Institute of Organic Chemistry, Goethe-University Frankfurt, Frankfurt am Main 60438, Germany.
| | - Josef Wachtveitl
- Institute of Physical and Theoretical Chemistry, Goethe-University Frankfurt, Frankfurt am Main 60438, Germany.
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