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L'Hôte, Valentin
Publications (2 of 2) Show all publications
Doimo, M., Chaudhari, N., Abrahamsson, S., L'Hôte, V., Nguyen, T. V. H., Berner, A., . . . Wanrooij, S. (2023). Enhanced mitochondrial G-quadruplex formation impedes replication fork progression leading to mtDNA loss in human cells. Nucleic Acids Research, 51(14), 7392-7408
Open this publication in new window or tab >>Enhanced mitochondrial G-quadruplex formation impedes replication fork progression leading to mtDNA loss in human cells
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2023 (English)In: Nucleic Acids Research, ISSN 0305-1048, E-ISSN 1362-4962, Vol. 51, no 14, p. 7392-7408Article in journal (Refereed) Published
Abstract [en]

Mitochondrial DNA (mtDNA) replication stalling is considered an initial step in the formation of mtDNA deletions that associate with genetic inherited disorders and aging. However, the molecular details of how stalled replication forks lead to mtDNA deletions accumulation are still unclear. Mitochondrial DNA deletion breakpoints preferentially occur at sequence motifs predicted to form G-quadruplexes (G4s), four-stranded nucleic acid structures that can fold in guanine-rich regions. Whether mtDNA G4s form in vivo and their potential implication for mtDNA instability is still under debate. In here, we developed new tools to map G4s in the mtDNA of living cells. We engineered a G4-binding protein targeted to the mitochondrial matrix of a human cell line and established the mtG4-ChIP method, enabling the determination of mtDNA G4s under different cellular conditions. Our results are indicative of transient mtDNA G4 formation in human cells. We demonstrate that mtDNA-specific replication stalling increases formation of G4s, particularly in the major arc. Moreover, elevated levels of G4 block the progression of the mtDNA replication fork and cause mtDNA loss. We conclude that stalling of the mtDNA replisome enhances mtDNA G4 occurrence, and that G4s not resolved in a timely manner can have a negative impact on mtDNA integrity.

Place, publisher, year, edition, pages
Oxford University Press, 2023
National Category
Cell and Molecular Biology
Identifiers
urn:nbn:se:umu:diva-214069 (URN)10.1093/nar/gkad535 (DOI)001030190900001 ()37351621 (PubMedID)2-s2.0-85168980694 (Scopus ID)
Funder
Knut and Alice Wallenberg FoundationSwedish Research Council, VR-MH 2018-0278Swedish Research Council, VR-NT 2017-05235The Kempe Foundations, SMK-1632Wenner-Gren FoundationsEU, Horizon 2020, 751474Swedish Foundation for Strategic Research, RIF14-0081
Available from: 2023-09-05 Created: 2023-09-05 Last updated: 2023-09-05Bibliographically approved
Prasad, B., Doimo, M., Andréasson, M., L'Hôte, V., Chorell, E. & Wanrooij, S. (2022). A complementary chemical probe approach towards customized studies of G-quadruplex DNA structures in live cells. Chemical Science, 13(8), 2347-2354
Open this publication in new window or tab >>A complementary chemical probe approach towards customized studies of G-quadruplex DNA structures in live cells
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2022 (English)In: Chemical Science, ISSN 2041-6520, E-ISSN 2041-6539, Vol. 13, no 8, p. 2347-2354Article in journal (Refereed) Published
Abstract [en]

G-quadruplex (G4) DNA structures are implicated in central biological processes and are considered promising therapeutic targets because of their links to human diseases such as cancer. However, functional details of how, when, and why G4 DNA structures form in vivo are largely missing leaving a knowledge gap that requires tailored chemical biology studies in relevant live-cell model systems. Towards this end, we developed a synthetic platform to generate complementary chemical probes centered around one of the most effective and selective G4 stabilizing compounds, Phen-DC3. We used a structure-based design and substantial synthetic devlopments to equip Phen-DC3 with an amine in a position that does not interfere with G4 interactions. We next used this reactive handle to conjugate a BODIPY fluorophore to Phen-DC3. This generated a fluorescent derivative with retained G4 selectivity, G4 stabilization, and cellular effect that revealed the localization and function of Phen-DC3 in human cells. To increase cellular uptake, a second chemical probe with a conjugated cell-penetrating peptide was prepared using the same amine-substituted Phen-DC3 derivative. The cell-penetrating peptide conjugation, while retaining G4 selectivity and stabilization, increased nuclear localization and cellular effects, showcasing the potential of this method to modulate and direct cellular uptake e.g. as delivery vehicles. The applied approach to generate multiple tailored biochemical tools based on the same core structure can thus be used to advance the studies of G4 biology to uncover molecular details and therapeutic approaches. This journal is

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2022
National Category
Biochemistry and Molecular Biology
Identifiers
urn:nbn:se:umu:diva-193064 (URN)10.1039/d1sc05816a (DOI)000751956900001 ()2-s2.0-85125772577 (Scopus ID)
Funder
Swedish Research Council, VR-NT 2017-05235The Kempe Foundations, SMK-1632Knut and Alice Wallenberg Foundation, VR-MH 2018-0278EU, Horizon 2020, 751474
Available from: 2022-03-21 Created: 2022-03-21 Last updated: 2023-03-24Bibliographically approved
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