LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 10 of total 17

Search options

  1. Article ; Online: Eukaryotic DNA replication with purified budding yeast proteins.

    Posse, Viktor / Johansson, Erik / Diffley, John F X

    Methods in enzymology

    2021  Volume 661, Page(s) 1–33

    Abstract: The in vitro reconstitution of origin firing was a key step toward the biochemical reconstitution of eukaryotic DNA replication in budding yeast. Today the basic replication assay involves proteins purified from 24 separate protocols that have evolved ... ...

    Abstract The in vitro reconstitution of origin firing was a key step toward the biochemical reconstitution of eukaryotic DNA replication in budding yeast. Today the basic replication assay involves proteins purified from 24 separate protocols that have evolved since their first publication, and as a result, the efficiency and reliability of the in vitro replication system has improved. Here we will present protocols for all 24 purifications together with a general protocol for the in vitro replication assay and some tips for troubleshooting problems with the assay.
    MeSH term(s) DNA Replication ; DNA, Fungal/genetics ; DNA, Fungal/metabolism ; Fungal Proteins/metabolism ; Replication Origin ; Reproducibility of Results ; Saccharomyces cerevisiae/genetics ; Saccharomyces cerevisiae/metabolism ; Saccharomyces cerevisiae Proteins/genetics ; Saccharomyces cerevisiae Proteins/metabolism ; Saccharomycetales/genetics ; Saccharomycetales/metabolism
    Chemical Substances DNA, Fungal ; Fungal Proteins ; Saccharomyces cerevisiae Proteins
    Language English
    Publishing date 2021-10-22
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ISSN 1557-7988
    ISSN (online) 1557-7988
    DOI 10.1016/bs.mie.2021.08.018
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  2. Article ; Online: Ribonucleotides embedded in template DNA impair mitochondrial RNA polymerase progression.

    Singh, Meenakshi / Posse, Viktor / Peter, Bradley / Falkenberg, Maria / Gustafsson, Claes M

    Nucleic acids research

    2022  Volume 50, Issue 2, Page(s) 989–999

    Abstract: Human mitochondria lack ribonucleotide excision repair pathways, causing misincorporated ribonucleotides (rNMPs) to remain embedded in the mitochondrial genome. Previous studies have demonstrated that human mitochondrial DNA polymerase γ can bypass a ... ...

    Abstract Human mitochondria lack ribonucleotide excision repair pathways, causing misincorporated ribonucleotides (rNMPs) to remain embedded in the mitochondrial genome. Previous studies have demonstrated that human mitochondrial DNA polymerase γ can bypass a single rNMP, but that longer stretches of rNMPs present an obstacle to mitochondrial DNA replication. Whether embedded rNMPs also affect mitochondrial transcription has not been addressed. Here we demonstrate that mitochondrial RNA polymerase elongation activity is affected by a single, embedded rNMP in the template strand. The effect is aggravated at stretches with two or more consecutive rNMPs in a row and cannot be overcome by addition of the mitochondrial transcription elongation factor TEFM. Our findings lead us to suggest that impaired transcription may be of functional relevance in genetic disorders associated with imbalanced nucleotide pools and higher levels of embedded rNMPs.
    MeSH term(s) DNA/metabolism ; DNA Polymerase gamma/metabolism ; DNA Replication ; Escherichia coli/genetics ; Humans ; Mitochondria/genetics ; RNA, Mitochondrial/metabolism ; Ribonucleotides/metabolism
    Chemical Substances RNA, Mitochondrial ; Ribonucleotides ; DNA (9007-49-2) ; DNA Polymerase gamma (EC 2.7.7.7)
    Language English
    Publishing date 2022-01-11
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 186809-3
    ISSN 1362-4962 ; 1362-4954 ; 0301-5610 ; 0305-1048
    ISSN (online) 1362-4962 ; 1362-4954
    ISSN 0301-5610 ; 0305-1048
    DOI 10.1093/nar/gkab1251
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  3. Article ; Online: Human Mitochondrial Transcription Factor B2 Is Required for Promoter Melting during Initiation of Transcription.

    Posse, Viktor / Gustafsson, Claes M

    The Journal of biological chemistry

    2016  Volume 292, Issue 7, Page(s) 2637–2645

    Abstract: The mitochondrial transcription initiation machinery in humans consists of three proteins: the RNA polymerase (POLRMT) and two accessory factors, transcription factors A and B2 (TFAM and TFB2M, respectively). This machinery is required for the expression ...

    Abstract The mitochondrial transcription initiation machinery in humans consists of three proteins: the RNA polymerase (POLRMT) and two accessory factors, transcription factors A and B2 (TFAM and TFB2M, respectively). This machinery is required for the expression of mitochondrial DNA and the biogenesis of the oxidative phosphorylation system. Previous experiments suggested that TFB2M is required for promoter melting, but conclusive experimental proof for this effect has not been presented. Moreover, the role of TFB2M in promoter unwinding has not been discriminated from that of TFAM. Here we used potassium permanganate footprinting, DNase I footprinting, and
    MeSH term(s) DNA Footprinting ; Humans ; Methyltransferases/metabolism ; Mitochondria/metabolism ; Mitochondrial Proteins/metabolism ; Phosphorylation ; Promoter Regions, Genetic ; Transcription Factors/metabolism ; Transcription, Genetic
    Chemical Substances Mitochondrial Proteins ; Transcription Factors ; Methyltransferases (EC 2.1.1.-) ; TFB2M protein, human (EC 2.1.1.-)
    Language English
    Publishing date 2016-12-27
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2997-x
    ISSN 1083-351X ; 0021-9258
    ISSN (online) 1083-351X
    ISSN 0021-9258
    DOI 10.1074/jbc.M116.751008
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  4. Article: Non-coding 7S RNA inhibits transcription via mitochondrial RNA polymerase dimerization

    Zhu, Xuefeng / Xie, Xie / Das, Hrishikesh / Tan, Benedict G. / Shi, Yonghong / Al-Behadili, Ali / Peter, Bradley / Motori, Elisa / Valenzuela, Sebastian / Posse, Viktor / Gustafsson, Claes M. / Hällberg, B. Martin / Falkenberg, Maria

    Cell. 2022 June 23, v. 185, no. 13

    2022  

    Abstract: The mitochondrial genome encodes 13 components of the oxidative phosphorylation system, and altered mitochondrial transcription drives various human pathologies. A polyadenylated, non-coding RNA molecule known as 7S RNA is transcribed from a region ... ...

    Abstract The mitochondrial genome encodes 13 components of the oxidative phosphorylation system, and altered mitochondrial transcription drives various human pathologies. A polyadenylated, non-coding RNA molecule known as 7S RNA is transcribed from a region immediately downstream of the light strand promoter in mammalian cells, and its levels change rapidly in response to physiological conditions. Here, we report that 7S RNA has a regulatory function, as it controls levels of mitochondrial transcription both in vitro and in cultured human cells. Using cryo-EM, we show that POLRMT dimerization is induced by interactions with 7S RNA. The resulting POLRMT dimer interface sequesters domains necessary for promoter recognition and unwinding, thereby preventing transcription initiation. We propose that the non-coding 7S RNA molecule is a component of a negative feedback loop that regulates mitochondrial transcription in mammalian cells.
    Keywords DNA-directed RNA polymerase ; dimerization ; humans ; mitochondria ; mitochondrial RNA ; mitochondrial genome ; non-coding RNA ; oxidative phosphorylation ; transcription initiation
    Language English
    Dates of publication 2022-0623
    Size p. 2309-2323.e24.
    Publishing place Elsevier Inc.
    Document type Article
    ZDB-ID 187009-9
    ISSN 1097-4172 ; 0092-8674
    ISSN (online) 1097-4172
    ISSN 0092-8674
    DOI 10.1016/j.cell.2022.05.006
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

  5. Article ; Online: Non-coding 7S RNA inhibits transcription via mitochondrial RNA polymerase dimerization.

    Zhu, Xuefeng / Xie, Xie / Das, Hrishikesh / Tan, Benedict G / Shi, Yonghong / Al-Behadili, Ali / Peter, Bradley / Motori, Elisa / Valenzuela, Sebastian / Posse, Viktor / Gustafsson, Claes M / Hällberg, B Martin / Falkenberg, Maria

    Cell

    2022  Volume 185, Issue 13, Page(s) 2309–2323.e24

    Abstract: The mitochondrial genome encodes 13 components of the oxidative phosphorylation system, and altered mitochondrial transcription drives various human pathologies. A polyadenylated, non-coding RNA molecule known as 7S RNA is transcribed from a region ... ...

    Abstract The mitochondrial genome encodes 13 components of the oxidative phosphorylation system, and altered mitochondrial transcription drives various human pathologies. A polyadenylated, non-coding RNA molecule known as 7S RNA is transcribed from a region immediately downstream of the light strand promoter in mammalian cells, and its levels change rapidly in response to physiological conditions. Here, we report that 7S RNA has a regulatory function, as it controls levels of mitochondrial transcription both in vitro and in cultured human cells. Using cryo-EM, we show that POLRMT dimerization is induced by interactions with 7S RNA. The resulting POLRMT dimer interface sequesters domains necessary for promoter recognition and unwinding, thereby preventing transcription initiation. We propose that the non-coding 7S RNA molecule is a component of a negative feedback loop that regulates mitochondrial transcription in mammalian cells.
    MeSH term(s) Animals ; DNA, Mitochondrial/genetics ; DNA-Directed RNA Polymerases/metabolism ; Dimerization ; Humans ; Mammals/metabolism ; Mitochondrial Proteins/genetics ; Mitochondrial Proteins/metabolism ; RNA/metabolism ; RNA, Mitochondrial ; RNA, Small Cytoplasmic ; Signal Recognition Particle ; Transcription, Genetic
    Chemical Substances 7SL RNA ; DNA, Mitochondrial ; Mitochondrial Proteins ; RNA, Mitochondrial ; RNA, Small Cytoplasmic ; Signal Recognition Particle ; RNA (63231-63-0) ; DNA-Directed RNA Polymerases (EC 2.7.7.6)
    Language English
    Publishing date 2022-06-02
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 187009-9
    ISSN 1097-4172 ; 0092-8674
    ISSN (online) 1097-4172
    ISSN 0092-8674
    DOI 10.1016/j.cell.2022.05.006
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  6. Article ; Online: Identifying SARS-CoV-2 antiviral compounds by screening for small molecule inhibitors of nsp12/7/8 RNA-dependent RNA polymerase.

    Bertolin, Agustina P / Weissmann, Florian / Zeng, Jingkun / Posse, Viktor / Milligan, Jennifer C / Canal, Berta / Ulferts, Rachel / Wu, Mary / Drury, Lucy S / Howell, Michael / Beale, Rupert / Diffley, John F X

    The Biochemical journal

    2021  Volume 478, Issue 13, Page(s) 2425–2443

    Abstract: The coronavirus disease 2019 (COVID-19) global pandemic has turned into the largest public health and economic crisis in recent history impacting virtually all sectors of society. There is a need for effective therapeutics to battle the ongoing pandemic. ...

    Abstract The coronavirus disease 2019 (COVID-19) global pandemic has turned into the largest public health and economic crisis in recent history impacting virtually all sectors of society. There is a need for effective therapeutics to battle the ongoing pandemic. Repurposing existing drugs with known pharmacological safety profiles is a fast and cost-effective approach to identify novel treatments. The COVID-19 etiologic agent is the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a single-stranded positive-sense RNA virus. Coronaviruses rely on the enzymatic activity of the replication-transcription complex (RTC) to multiply inside host cells. The RTC core catalytic component is the RNA-dependent RNA polymerase (RdRp) holoenzyme. The RdRp is one of the key druggable targets for CoVs due to its essential role in viral replication, high degree of sequence and structural conservation and the lack of homologues in human cells. Here, we have expressed, purified and biochemically characterised active SARS-CoV-2 RdRp complexes. We developed a novel fluorescence resonance energy transfer-based strand displacement assay for monitoring SARS-CoV-2 RdRp activity suitable for a high-throughput format. As part of a larger research project to identify inhibitors for all the enzymatic activities encoded by SARS-CoV-2, we used this assay to screen a custom chemical library of over 5000 approved and investigational compounds for novel SARS-CoV-2 RdRp inhibitors. We identified three novel compounds (GSK-650394, C646 and BH3I-1) and confirmed suramin and suramin-like compounds as in vitro SARS-CoV-2 RdRp activity inhibitors. We also characterised the antiviral efficacy of these drugs in cell-based assays that we developed to monitor SARS-CoV-2 growth.
    MeSH term(s) Animals ; Antiviral Agents/chemistry ; Antiviral Agents/pharmacology ; Benzoates/pharmacology ; Bridged Bicyclo Compounds, Heterocyclic/pharmacology ; Chlorocebus aethiops ; Coronavirus RNA-Dependent RNA Polymerase/antagonists & inhibitors ; Coronavirus RNA-Dependent RNA Polymerase/metabolism ; Drug Evaluation, Preclinical ; Enzyme Assays ; Fluorescence Resonance Energy Transfer ; High-Throughput Screening Assays ; Holoenzymes/metabolism ; Reproducibility of Results ; SARS-CoV-2/drug effects ; SARS-CoV-2/enzymology ; Small Molecule Libraries/chemistry ; Small Molecule Libraries/pharmacology ; Suramin/pharmacology ; Vero Cells ; Viral Nonstructural Proteins/antagonists & inhibitors ; Viral Nonstructural Proteins/metabolism
    Chemical Substances Antiviral Agents ; Benzoates ; Bridged Bicyclo Compounds, Heterocyclic ; Holoenzymes ; NS8 protein, SARS-CoV-2 ; Small Molecule Libraries ; Viral Nonstructural Proteins ; 2-cyclopentyl-4-(5-phenyl-1H-pyrrolo(2,3-b)pyridin-3-yl)-benzoic acid (56887611DJ) ; Suramin (6032D45BEM) ; Coronavirus RNA-Dependent RNA Polymerase (EC 2.7.7.48) ; NSP12 protein, SARS-CoV-2 (EC 2.7.7.48) ; NSP7 protein, SARS-CoV-2 (EC 2.7.7.48)
    Language English
    Publishing date 2021-07-01
    Publishing country England
    Document type Journal Article
    ZDB-ID 2969-5
    ISSN 1470-8728 ; 0006-2936 ; 0306-3275 ; 0264-6021
    ISSN (online) 1470-8728
    ISSN 0006-2936 ; 0306-3275 ; 0264-6021
    DOI 10.1042/BCJ20210200
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  7. Article ; Online: RNase H1 directs origin-specific initiation of DNA replication in human mitochondria.

    Posse, Viktor / Al-Behadili, Ali / Uhler, Jay P / Clausen, Anders R / Reyes, Aurelio / Zeviani, Massimo / Falkenberg, Maria / Gustafsson, Claes M

    PLoS genetics

    2019  Volume 15, Issue 1, Page(s) e1007781

    Abstract: Human mitochondrial DNA (mtDNA) replication is first initiated at the origin of H-strand replication. The initiation depends on RNA primers generated by transcription from an upstream promoter (LSP). Here we reconstitute this process in vitro using ... ...

    Abstract Human mitochondrial DNA (mtDNA) replication is first initiated at the origin of H-strand replication. The initiation depends on RNA primers generated by transcription from an upstream promoter (LSP). Here we reconstitute this process in vitro using purified transcription and replication factors. The majority of all transcription events from LSP are prematurely terminated after ~120 nucleotides, forming stable R-loops. These nascent R-loops cannot directly prime mtDNA synthesis, but must first be processed by RNase H1 to generate 3'-ends that can be used by DNA polymerase γ to initiate DNA synthesis. Our findings are consistent with recent studies of a knockout mouse model, which demonstrated that RNase H1 is required for R-loop processing and mtDNA maintenance in vivo. Both R-loop formation and DNA replication initiation are stimulated by the mitochondrial single-stranded DNA binding protein. In an RNase H1 deficient patient cell line, the precise initiation of mtDNA replication is lost and DNA synthesis is initiated from multiple sites throughout the mitochondrial control region. In combination with previously published in vivo data, the findings presented here suggest a model, in which R-loop processing by RNase H1 directs origin-specific initiation of DNA replication in human mitochondria.
    MeSH term(s) Animals ; DNA Polymerase gamma/genetics ; DNA Replication/genetics ; DNA, Mitochondrial/biosynthesis ; DNA, Mitochondrial/genetics ; DNA-Binding Proteins/genetics ; Humans ; Mice ; Mitochondria/genetics ; Replication Origin/genetics ; Ribonuclease H/genetics
    Chemical Substances DNA, Mitochondrial ; DNA-Binding Proteins ; DNA Polymerase gamma (EC 2.7.7.7) ; Ribonuclease H (EC 3.1.26.4) ; ribonuclease HI (EC 3.1.26.4)
    Language English
    Publishing date 2019-01-03
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2186725-2
    ISSN 1553-7404 ; 1553-7390
    ISSN (online) 1553-7404
    ISSN 1553-7390
    DOI 10.1371/journal.pgen.1007781
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  8. Article ; Online: TEFM is a potent stimulator of mitochondrial transcription elongation in vitro.

    Posse, Viktor / Shahzad, Saba / Falkenberg, Maria / Hällberg, B Martin / Gustafsson, Claes M

    Nucleic acids research

    2015  Volume 43, Issue 5, Page(s) 2615–2624

    Abstract: A single-subunit RNA polymerase, POLRMT, transcribes the mitochondrial genome in human cells. Recently, a factor termed as the mitochondrial transcription elongation factor, TEFM, was shown to stimulate transcription elongation in vivo, but its effect in ...

    Abstract A single-subunit RNA polymerase, POLRMT, transcribes the mitochondrial genome in human cells. Recently, a factor termed as the mitochondrial transcription elongation factor, TEFM, was shown to stimulate transcription elongation in vivo, but its effect in vitro was relatively modest. In the current work, we have isolated active TEFM in recombinant form and used a reconstituted in vitro transcription system to characterize its activities. We show that TEFM strongly promotes POLRMT processivity as it dramatically stimulates the formation of longer transcripts. TEFM also abolishes premature transcription termination at conserved sequence block II, an event that has been linked to primer formation during initiation of mtDNA synthesis. We show that POLRMT pauses at a wide range of sites in a given DNA sequence. In the absence of TEFM, this leads to termination; however, the presence of TEFM abolishes this effect and aids POLRMT in continuation of transcription. Further, we show that TEFM substantially increases the POLRMT affinity to an elongation-like DNA:RNA template. In combination with previously published in vivo observations, our data establish TEFM as an essential component of the mitochondrial transcription machinery.
    MeSH term(s) Cell-Free System ; DNA/genetics ; DNA/metabolism ; DNA Damage ; DNA, Mitochondrial/genetics ; DNA, Mitochondrial/metabolism ; DNA-Directed RNA Polymerases/genetics ; DNA-Directed RNA Polymerases/metabolism ; Deoxyguanosine/analogs & derivatives ; Deoxyguanosine/genetics ; Deoxyguanosine/metabolism ; Genome, Mitochondrial/genetics ; Humans ; Mitochondria/genetics ; Mitochondria/metabolism ; Mitochondrial Proteins/genetics ; Mitochondrial Proteins/metabolism ; Models, Genetic ; Protein Binding ; Recombinant Proteins/metabolism ; Templates, Genetic ; Transcription Factors/genetics ; Transcription Factors/metabolism ; Transcription, Genetic
    Chemical Substances DNA, Mitochondrial ; Mitochondrial Proteins ; Recombinant Proteins ; TEFM protein, human ; Transcription Factors ; 8-oxo-7-hydrodeoxyguanosine (88847-89-6) ; DNA (9007-49-2) ; DNA-Directed RNA Polymerases (EC 2.7.7.6) ; POLRMT protein, human (EC 2.7.7.6) ; Deoxyguanosine (G9481N71RO)
    Language English
    Publishing date 2015-03-11
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 186809-3
    ISSN 1362-4962 ; 1362-4954 ; 0301-5610 ; 0305-1048
    ISSN (online) 1362-4962 ; 1362-4954
    ISSN 0301-5610 ; 0305-1048
    DOI 10.1093/nar/gkv105
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  9. Article ; Online: Identifying SARS-CoV-2 Antiviral Compounds by Screening for Small Molecule Inhibitors of Nsp12/7/8 RNA-dependent RNA Polymerase

    Beale, Rupert / Bertolin, Agustina P / Canal, Berta / Diffley, John FX / Drury, Lucy S / Howell, Michael / Milligan, Jennifer / Posse, Viktor / Ulferts, Rachel / Weissmann, Florian / Wu, Mary / Zeng, Jingkun

    bioRxiv

    Abstract: The coronavirus disease 2019 (COVID-19) global pandemic has turned into the largest public health and economic crisis in recent history impacting virtually all sectors of society. There is a need for effective therapeutics to battle the ongoing pandemic. ...

    Abstract The coronavirus disease 2019 (COVID-19) global pandemic has turned into the largest public health and economic crisis in recent history impacting virtually all sectors of society. There is a need for effective therapeutics to battle the ongoing pandemic. Repurposing existing drugs with known pharmacological safety profiles is a fast and cost-effective approach to identify novel treatments. The COVID-19 etiologic agent is the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a single-stranded positive-sense RNA virus. Coronaviruses rely on the enzymatic activity of the replication-transcription complex (RTC) to multiply inside host cells. The RTC core catalytic component is the RNA-dependent RNA polymerase (RdRp) holoenzyme. The RdRp is one of the key druggable targets for CoVs due to its essential role in viral replication, high degree of sequence and structural conservation and the lack of homologs in human cells. Here, we have expressed, purified and biochemically characterised active SARS-CoV-2 RdRp complexes. We developed a novel fluorescence resonance energy transfer (FRET)-based strand displacement assay for monitoring SARS-CoV-2 RdRp activity suitable for a high-throughput format. As part of a larger research project to identify inhibitors for all the enzymatic activities encoded by SARS-CoV-2, we used this assay to screen a custom chemical library of over 5000 approved and investigational compounds for novel SARS-CoV-2 RdRp inhibitors. We identified 3 novel compounds (GSK-650394, C646 and BH3I-1) and confirmed suramin and suramin-like compounds as in vitro SARS-CoV-2 RdRp activity inhibitors. We also characterised the antiviral efficacy of these drugs in cell-based assays that we developed to monitor SARS-CoV-2 growth.
    Keywords covid19
    Language English
    Publishing date 2021-04-08
    Publisher Cold Spring Harbor Laboratory
    Document type Article ; Online
    DOI 10.1101/2021.04.07.438807
    Database COVID19

    Kategorien

  10. Article ; Online: Mitochondrial transcription termination factor 1 directs polar replication fork pausing.

    Shi, Yonghong / Posse, Viktor / Zhu, Xuefeng / Hyvärinen, Anne K / Jacobs, Howard T / Falkenberg, Maria / Gustafsson, Claes M

    Nucleic acids research

    2016  Volume 44, Issue 12, Page(s) 5732–5742

    Abstract: During replication of nuclear ribosomal DNA (rDNA), clashes with the transcription apparatus can cause replication fork collapse and genomic instability. To avoid this problem, a replication fork barrier protein is situated downstream of rDNA, there ... ...

    Abstract During replication of nuclear ribosomal DNA (rDNA), clashes with the transcription apparatus can cause replication fork collapse and genomic instability. To avoid this problem, a replication fork barrier protein is situated downstream of rDNA, there preventing replication in the direction opposite rDNA transcription. A potential candidate for a similar function in mitochondria is the mitochondrial transcription termination factor 1 (MTERF1, also denoted mTERF), which binds to a sequence just downstream of the ribosomal transcription unit. Previous studies have shown that MTERF1 prevents antisense transcription over the ribosomal RNA genes, a process which we here show to be independent of the transcription elongation factor TEFM. Importantly, we now demonstrate that MTERF1 arrests mitochondrial DNA (mtDNA) replication with distinct polarity. The effect is explained by the ability of MTERF1 to act as a directional contrahelicase, blocking mtDNA unwinding by the mitochondrial helicase TWINKLE. This conclusion is also supported by in vivo evidence that MTERF1 stimulates TWINKLE pausing. We conclude that MTERF1 can direct polar replication fork arrest in mammalian mitochondria.
    MeSH term(s) Basic-Leucine Zipper Transcription Factors/genetics ; Basic-Leucine Zipper Transcription Factors/metabolism ; DNA Helicases/genetics ; DNA Helicases/metabolism ; DNA Replication ; DNA, Mitochondrial/genetics ; DNA, Mitochondrial/metabolism ; DNA, Ribosomal/genetics ; DNA, Ribosomal/metabolism ; HEK293 Cells ; Humans ; Mitochondria/genetics ; Mitochondria/metabolism ; Mitochondrial Proteins/genetics ; Mitochondrial Proteins/metabolism ; RNA, Ribosomal/genetics ; RNA, Ribosomal/metabolism ; Transcription Factors/genetics ; Transcription Factors/metabolism ; Transcription, Genetic
    Chemical Substances Basic-Leucine Zipper Transcription Factors ; DNA, Mitochondrial ; DNA, Ribosomal ; MTERF1 protein, human ; Mitochondrial Proteins ; RNA, Ribosomal ; TEFM protein, human ; Transcription Factors ; DNA Helicases (EC 3.6.4.-) ; TWNK protein, human (EC 3.6.4.12)
    Language English
    Publishing date 2016-04-25
    Publishing country England
    Document type Journal Article
    ZDB-ID 186809-3
    ISSN 1362-4962 ; 1362-4954 ; 0301-5610 ; 0305-1048
    ISSN (online) 1362-4962 ; 1362-4954
    ISSN 0301-5610 ; 0305-1048
    DOI 10.1093/nar/gkw302
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

To top