Laurie S Kaguni

University of Tampere, Tammerfors, Pirkanmaa, Finland

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Publications (83)373.76 Total impact

  • Grzegorz L. Ciesielski · Vesa P. Hytönen · Laurie S. Kaguni ·
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    ABSTRACT: A lack of effective treatment for mitochondrial diseases prompts scientists to investigate the molecular processes that underlie their development. The major cause of mitochondrial diseases is dysfunction of the sole mitochondrial DNA polymerase, DNA polymerase γ (Pol γ). The development of treatment strategies will require a detailed characterization of the molecular properties of Pol γ. A novel technique, biolayer interferometry, allows one to monitor molecular interactions in real time, thus providing an insight into the kinetics of the process. Here, we present an application of the biolayer interferometry technique to characterize the fundamental reactions that Pol γ undergoes during the initiation phase of mitochondrial DNA replication: holoenzyme formation and binding to the primer-template.
    01/2016: pages 223-231;
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    ABSTRACT: The mitochondrial single-stranded DNA-binding protein (mtSSB) coordinates the function of replisome components at the mitochondrial replication fork. In recent years, it has been demonstrated that mtSSB stimulates the activities of DNA polymerase γ (Pol γ) and mitochondrial DNA (mtDNA) helicase in a concentration-dependent manner. Here we present a new approach to purify the human mtSSB and our standard assays to evaluate its biochemical properties, including a Gel Mobility Shift Assay (GMSA) to assess single-stranded DNA (ssDNA) binding activity, and an assay to assess SSB stimulation of Pol γ activity.
    01/2016: pages 211-222;
  • Fernando A. Rosado-Ruiz · Minyoung So · Laurie S. Kaguni ·
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    ABSTRACT: The replicative mitochondrial DNA (mtDNA) helicase is essential for mtDNA replication and maintenance of the mitochondrial genome. Despite substantial advances that have been made in its characterization, there is still much to be understood about the functional roles of its domains and its interactions with the other components of the minimal mitochondrial DNA replisome. Critical to achieving this is the ability to isolate the enzyme in a stable, active form. In this chapter we describe a modified, streamlined purification strategy for recombinant forms of the enzyme. We also present assays to assess its helix unwinding activity and the stimulatory effects of the mitochondrial single-stranded DNA-binding protein (mtSSB). Finally, we describe a concentration/buffer exchange method that we have employed to achieve greater enzyme stability and appropriate conditions for biochemical and biophysical studies.
    01/2016: pages 185-198;
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    ABSTRACT: The activity of the mitochondrial replicase, DNA polymerase γ (Pol γ) is stimulated by another key component of the mitochondrial replisome, the mitochondrial single-stranded DNA-binding protein (mtSSB). We have performed a comparative analysis of the human and Drosophila Pol γs with their cognate mtSSBs, evaluating their functional relationships using a combined approach of biochemical assays and electron microscopy. We found that increasing concentrations of both mtSSBs led to the elimination of template secondary structure and gradual opening of the template DNA, through a series of visually similar template species. The stimulatory effect of mtSSB on Pol γ is not species-specific. We observed that human mtSSB can be substituted by its Drosophila homologue, and vice versa, finding that a lower concentration of insect mtSSB promotes efficient stimulation of either Pol. Notably, distinct phases of the stimulation by both mtSSBs are distinguishable, and are characterized by a similar organization of the template DNA for both Pol γs. We conclude that organization of the template DNA is the major factor contributing to the stimulation of Pol γ activity. Additionally, we observed that human Pol γ preferentially utilizes compacted templates, whereas the insect enzyme achieves its maximal activity on open templates, emphasizing the relative importance of template DNA organization in modulating Pol γ activity, and the variation among systems.
    Journal of Biological Chemistry 10/2015; DOI:10.1074/jbc.M115.673707 · 4.57 Impact Factor
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    Marcos T Oliveira · Jani Haukka · Laurie S Kaguni ·
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    ABSTRACT: The large number of complete mitochondrial DNA (mtDNA) sequences available for metazoan species makes it a good system for studying genome diversity, although little is known about the mechanisms that promote and/ or are correlated with the evolution of this organellar genome. By investigating the molecular evolutionary history of the catalytic and accessory subunits of the mtDNA polymerase, pol γ, we sought to develop mechanistic insight into its function that might impact genome structure by exploring the relationships between DNA replication and animal mitochondrial genome diversity. We identified three evolutionary patterns among metazoan pol γs. First, a trend towards stabilization of both sequence and structure occurred in vertebrates, with both subunits evolving distinctly from those of other animal groups, and acquiring at least four novel structural elements, the most important of which is the HLH-3β domain that allows the accessory subunit to homodimerize. Second, both subunits of arthropods and tunicates have become shorter and evolved approximately twice as rapidly as their vertebrate homologues. And third, nematodes have lost the gene for the accessory subunit, which was accompanied by the loss of its interacting domain in the catalytic subunit of pol γ, and they show the highest rate of molecular evolution among all animal taxa. These findings correlate well with the mtDNA genomic features of each group described above, and with their modes of DNA replication, although a substantive amount of biochemical work is needed to draw conclusive links regarding the latter, especially for nematodes. Describing the parallels between evolution of pol γ and metazoan mtDNA architecture may also help in understanding the processes that lead to mitochondrial dysfunction and to human disease-related phenotypes. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.
    Genome Biology and Evolution 03/2015; 7(4). DOI:10.1093/gbe/evv042 · 4.23 Impact Factor
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    ABSTRACT: Mitochondrial DNA maintenance disorders are an important cause of hereditary ataxia syndrome, and the majority are associated with mutations in the gene encoding the catalytic subunit of the mitochondrial DNA polymerase (DNA polymerase gamma), POLG. Mutations resulting in the amino acid substitutions A467T and W748S are the most common genetic causes of inherited cerebellar ataxia in Europe. We report here a POLG mutational screening in a family with a mitochondrial ataxia phenotype. To evaluate the likely pathogenicity of each of the identified changes, a 3D structural analysis of the PolG protein was carried out, using the Alpers mutation clustering tool reported previously. Three novel nucleotide changes and the p.Q1236H polymorphism have been identified in the affected members of the pedigree. Computational analysis suggests that the p.K601E mutation is likely the major contributing factor to the pathogenic phenotype. Computational analysis of the PolG protein suggests that the p.K601E mutation is likely the most significant contributing factor to a pathogenic phenotype. However, the co-occurrence of multiple POLG alleles may be necessary in the development an adult-onset mitochondrial ataxia phenotype.
    BMC Research Notes 12/2014; 7(1):883. DOI:10.1186/1756-0500-7-883
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    ABSTRACT: The molecular mechanisms influencing healthspan are unclear but mitochondrial function, resistance to oxidative stress and proteostasis are recurring themes. Tumor necrosis factor Receptor Associated Protein 1 (TRAP1), the mitochondrial analogue of Hsp75, regulates levels of reactive oxygen species in vitro and is found expressed at higher levels in tumor cells where it is thought to play a pro-survival role. While TRAP1-directed compartmentalized protein folding is a promising target for cancer therapy, its role at the organismal level is unclear. Here we report that overexpression of TRAP1 in Drosophila extends healthspan by enhancing stress resistance, locomotor activity and fertility while depletion of TRAP1 has the opposite effect, with little effect on lifespan under both conditions. In addition, modulating TRAP1 expression promotes the nuclear translocation of homeobox protein Dve and increases expression of genes associated with the mitochondrial unfolded protein response (UPR(mt)), indicating an activation of this proteostasis pathway. Notably, independent genetic knockdown of components of the UPR(mt) pathway dampen the enhanced stress resistance observed in TRAP1 overexpression flies. Together these studies suggest that TRAP1 regulates healthspan, potentially through activation of the UPR(mt).
    Mechanisms of Ageing and Development 09/2014; 141-142. DOI:10.1016/j.mad.2014.09.002 · 3.40 Impact Factor
  • Johnny Stiban · Gregory A Farnum · Stacy L Hovde · Laurie S Kaguni ·
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    ABSTRACT: The metazoan mitochondrial DNA helicase is an integral part of the minimal mitochondrial replisome. It exhibits strong sequence homology with the bacteriophage T7 gene 4 protein primase-helicase (T7 gp4). Both proteins contain distinct N- and C-terminal domains separated by a flexible linker. The C-terminal domain catalyzes its characteristic DNA-dependent NTPase activity, and can unwind duplex DNA substrates independently of the N-terminal domain. Whereas the N-terminal domain in T7 gp4 contains a DNA primase activity, this function is lost in metazoan mtDNA helicase. Thus, although the functions of the C-terminal domain and the linker are partially understood, the role of the N-terminal region in the metazoan replicative mtDNA helicase remains elusive. Here, we show that the N-terminal domain of Drosophila melanogaster mtDNA helicase coordinates iron in a 2Fe-2S cluster that enhances protein stability in vitro. The N-terminal domain binds the cluster through conserved cysteine residues (Cys68, Cys71, Cys102, and Cys105) that are responsible for coordinating zinc in T7 gp4. Moreover, we show that the N-terminal domain binds both single- and double-stranded DNA oligomers, with an apparent Kd of ∼120 nm. These findings suggest a possible role for the N-terminal domain of metazoan mtDNA helicase in recruiting and binding DNA at the replication fork.
    Journal of Biological Chemistry 07/2014; 289(35). DOI:10.1074/jbc.M114.587774 · 4.57 Impact Factor
  • Laurie S. Kaguni · Gregory A. Farnum · Anssi Nurminen ·

    Biochimica et Biophysica Acta (BBA) - Bioenergetics 07/2014; 1837:e58. DOI:10.1016/j.bbabio.2014.05.227 · 5.35 Impact Factor
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    Gregory A. Farnum · Anssi Nurminen · Laurie S. Kaguni ·
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    ABSTRACT: We establish the genotype-phenotype correlations for the complete spectrum of POLG syndromes, by refining our previously described protocol for mapping pathogenic mutations in the human POLG gene to functional clusters in the catalytic core of the mitochondrial replicase, Pol γ (1). We assigned 136 mutations to five clusters and identify segments of primary sequence that can be used to delimit the boundaries of each cluster. We report that compound heterozygotes with two mutations from different clusters manifested more severe, earlier onset POLG syndromes, whereas two mutations from the same cluster are less common and generally are associated with less severe, later onset POLG syndromes. We also show that specific cluster combinations are more severe than others, and have a higher likelihood to manifest at an earlier age. Our clustering method provides a powerful tool to predict the pathogenic potential and predicted disease phenotype of novel variants and mutations in POLG, the most common nuclear gene underlying mitochondrial disorders. We propose that such a prediction tool would be useful for routine diagnostics for mitochondrial disorders. This article is part of a Special Issue entitled: 18th European Bioenergetic Conference. Guest Editors: Manuela Pereira and Miguel Teixeira.
    Biochimica et Biophysica Acta 07/2014; 1837(7). DOI:10.1016/j.bbabio.2014.01.021 · 4.66 Impact Factor
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    ABSTRACT: DREF [DRE (DNA replication-related element)-binding factor] controls the transcription of numerous genes in Drosophila, many involved in nuclear DNA (nDNA) replication and cell proliferation, three in mitochondrial DNA (mtDNA) replication and two in mtDNA transcription termination. In this work, we have analyzed the involvement of DREF in the expression of the known remaining genes engaged in the minimal mtDNA replication (d-mtDNA helicase) and transcription (the activator d-mtTFB2) machineries and of a gene involved in mitochondrial mRNAs translation (d-mtTFB1). We have identified their transcriptional initiation sites and subsequently DRE sequences in their promoter regions. Gel-shift and chromatin immunoprecipitation assays demonstrate that DREF interacts in vitro and in vivo with the d-mtDNA helicase and d-mtTFB2, but not with the d-mtTFB1 promoters. Transient transfection assays in Drosophila S2 cells with mutated DRE motifs and truncated promoter regions show that DREF controls the transcription of d-mtDNA helicase and d-mtTFB2, but not that of d-mtTFB1. RNA interference of DREF in S2 cells reinforces these results showing a decrease in the mRNA levels of d-mtDNA helicase and d-mtTFB2 and no changes in those of the d-mtTFB1. These results link the genetic regulation of nuclear DNA replication with the genetic control of mtDNA replication and transcription activation in Drosophila.
    Biochimica et Biophysica Acta 07/2013; 1829(10). DOI:10.1016/j.bbagrm.2013.07.006 · 4.66 Impact Factor
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    ABSTRACT: We show the physiological effects and molecular characterization of overexpression of the catalytic core of mitochondrial DNA (mtDNA) polymerase (pol γ-α) in muscle of Drosophila melanogaster. Muscle-specific overexpression of pol γ-α using the UAS/GAL4 (where UAS is upstream activation sequence) system produced more than 90% of lethality at the end of pupal stage at 25°C, and the survivor adult flies showed a significant reduction in life span. The survivor flies displayed a decreased mtDNA level that is accompanied by a corresponding decrease in the levels of the nucleoid-binding protein mitochondrial transcription factor A (mtTFA). Furthermore, an increase in apoptosis is detected in larvae and adults overexpressing pol γ-α. We suggest that the pupal lethality and reduced life span of survivor adult flies are both caused mainly by massive apoptosis of muscle cells induced by mtDNA depletion.
    Archives of Insect Biochemistry and Physiology 07/2013; 83(3). DOI:10.1002/arch.21101 · 1.02 Impact Factor
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    ABSTRACT: The human gene C10orf2 encodes the mitochondrial replicative DNA helicase Twinkle, mutations of which are responsible for a significant fraction of cases of autosomal dominant progressive external ophthalmoplegia (adPEO), a human mitochondrial disease caused by defects in intergenomic communication. We report the analysis of orthologous mutations in the Drosophila melanogaster mitochondrial DNA (mtDNA) helicase gene, d-mtDNA helicase. Increased expression of wild type d-mtDNA helicase using the UAS-GAL4 system leads to an increase in mtDNA copy number throughout adult life without any noteworthy phenotype, whereas overexpression of d-mtDNA helicase containing the K388A mutation in the helicase active site results in a severe depletion of mtDNA and a lethal phenotype. Overexpression of two d-mtDNA helicase variants equivalent to two human adPEO mutations shows differential effects. The A442P mutation exhibits a dominant negative effect similar to that of the active site mutant. In contrast, overexpression of d-mtDNA helicase containing the W441C mutation results in a slight decrease in mtDNA copy number during the third instar larval stage, and a moderate decrease in life span in the adult population. Overexpression of d-mtDNA helicase containing either the K388A or A442P mutations causes a mitochondrial oxidative phosphorylation (OXPHOS) defect that significantly reduces cell proliferation. The mitochondrial impairment caused by these mutations promotes apoptosis, arguing that mitochondria regulate programmed cell death in Drosophila. Our study of d-mtDNA helicase overexpression provides a tractable Drosophila model for understanding the cellular and molecular effects of human adPEO mutations.
    PLoS ONE 08/2012; 7(8):e43954. DOI:10.1371/journal.pone.0043954 · 3.23 Impact Factor
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    ABSTRACT: Phenotypes relevant to oxidative phosphorylation (OXPHOS) in eukaryotes are jointly determined by nuclear and mitochondrial DNA (mtDNA). Thus, in humans, the variable clinical presentations of mitochondrial disease patients bearing the same primary mutation, whether in nuclear or mitochondrial DNA, have been attributed to putative genetic determinants carried in the "other" genome, though their identity and the molecular mechanism(s) by which they might act remain elusive. Here we demonstrate cytoplasmic suppression of the mitochondrial disease-like phenotype of the Drosophila melanogaster nuclear mutant tko(25t), which includes developmental delay, seizure sensitivity, and defective male courtship. The tko(25t) strain carries a mutation in a mitoribosomal protein gene, causing OXPHOS deficiency due to defective intramitochondrial protein synthesis. Phenotypic suppression was associated with increased mtDNA copy number and increased mitochondrial biogenesis, as measured by the expression levels of porin voltage dependent anion channel and Spargel (PGC1α). Ubiquitous overexpression of Spargel in tko(25t) flies phenocopied the suppressor, identifying it as a key mechanistic target thereof. Suppressor-strain mtDNAs differed from related nonsuppressor strain mtDNAs by several coding-region polymorphisms and by length and sequence variation in the noncoding region (NCR), in which the origin of mtDNA replication is located. Cytoplasm from four of five originally Wolbachia-infected strains showed the same suppressor effect, whereas that from neither of two uninfected strains did so, suggesting that the stress of chronic Wolbachia infection may provide evolutionary selection for improved mitochondrial fitness under metabolic stress. Our findings provide a paradigm for understanding the role of mtDNA genotype in human disease.
    Genetics 07/2012; 192(2):483-93. DOI:10.1534/genetics.112.143719 · 5.96 Impact Factor
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    ABSTRACT: In Drosophila melanogaster, the mitochondrial transcription factor B1 (d-mtTFB1) transcript contains in its 5'-untranslated region a conserved upstream open reading frame denoted as CG42630 in FlyBase. We demonstrate that CG42630 encodes a novel protein, the coiled coil domain-containing protein 56 (CCDC56), conserved in metazoans. We show that Drosophila CCDC56 protein localizes to mitochondria and contains 87 amino acids in flies and 106 in humans with the two proteins sharing 42% amino acid identity. We show by rapid amplification of cDNA ends and Northern blotting that Drosophila CCDC56 protein and mtTFB1 are encoded on a bona fide bicistronic transcript. We report the generation and characterization of two ccdc56 knock-out lines in Drosophila carrying the ccdc56(D6) and ccdc56(D11) alleles. Lack of the CCDC56 protein in flies induces a developmental delay and 100% lethality by arrest of larval development at the third instar. ccdc56 knock-out larvae show a significant decrease in the level of fully assembled cytochrome c oxidase (COX) and in its activity, suggesting a defect in complex assembly; the activity of the other oxidative phosphorylation complexes remained either unaffected or increased in the ccdc56 knock-out larvae. The lethal phenotype and the decrease in COX were partially rescued by reintroduction of a wild-type UAS-ccdc56 transgene. These results indicate an important role for CCDC56 in the oxidative phosphorylation system and in particular in COX function required for proper development in D. melanogaster. We propose CCDC56 as a candidate factor required for COX biogenesis/assembly.
    Journal of Biological Chemistry 05/2012; 287(29):24174-85. DOI:10.1074/jbc.M112.343764 · 4.57 Impact Factor
  • Yuichi Matsushima · Laurie S Kaguni ·
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    ABSTRACT: Lon, ClpXP and m-AAA are the three major ATP-dependent proteases in the mitochondrial matrix. All three are involved in general quality control by degrading damaged or abnormal proteins. In addition to this role, they are proposed to serve roles in mitochondrial DNA functions including packaging and stability, replication, transcription and translation. In particular, Lon has been implicated in mtDNA metabolism in yeast, fly and humans. Here, we review the role of Lon protease in mitochondrial DNA functions, and discuss a putative physiological role for mitochondrial transcription factor A (TFAM) degradation by Lon protease. We also discuss the possible roles of m-AAA and ClpXP in mitochondrial DNA functions, and the putative candidate substrates for the three matrix proteases. This article is part of a Special Issue entitled: Mitochondrial Gene Expression.
    Biochimica et Biophysica Acta 12/2011; 1819(9-10):1080-7. DOI:10.1016/j.bbagrm.2011.11.008 · 4.66 Impact Factor
  • Marcos T Oliveira · Laurie S Kaguni ·
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    ABSTRACT: The mitochondrial single-stranded DNA-binding protein (mtSSB) is believed to coordinate the functions of DNA polymerase γ (pol γ) and the mitochondrial DNA (mtDNA) helicase at the mtDNA replication fork. We generated five variants of the human mtSSB bearing mutations in amino acid residues specific to metazoans that map on the protein surface, removed from the single-stranded DNA (ssDNA) binding groove. Although the mtSSB variants bound ssDNA with only slightly different affinities, they exhibited distinct capacities to stimulate the DNA polymerase activity of human pol γ and the DNA unwinding activity of human mtDNA helicase in vitro. Interestingly, we observed that the variants with defects in stimulating pol γ had unaltered capacities to stimulate the mtDNA helicase; at the same time, variants showing reduced stimulation of the mtDNA helicase activity promoted DNA synthesis by pol γ similarly to the wild-type mtSSB. The overexpression of the equivalent variants of Drosophila melanogaster mtSSB in S2 cells in culture caused mtDNA depletion under conditions of mitochondrial homeostasis. Furthermore, we observed more severe reduction of mtDNA copy number upon expression of these proteins during recovery from treatment with ethidium bromide, when mtDNA replication is stimulated in vivo. Our findings suggest that mtSSB uses distinct structural elements to interact functionally with its mtDNA replisome partners and to promote proper mtDNA replication in animal cells.
    Journal of Biological Chemistry 09/2011; 286(47):40649-58. DOI:10.1074/jbc.M111.289983 · 4.57 Impact Factor
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    Liliya Euro · Gregory A Farnum · Eino Palin · Anu Suomalainen · Laurie S Kaguni ·
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    ABSTRACT: Mutations in Pol γ represent a major cause of human mitochondrial diseases, especially those affecting the nervous system in adults and in children. Recessive mutations in Pol γ represent nearly half of those reported to date, and they are nearly uniformly distributed along the length of the POLG1 gene (Human DNA Polymerase gamma Mutation Database); the majority of them are linked to the most severe form of POLG syndrome, Alpers-Huttenlocher syndrome. In this report, we assess the structure-function relationships for recessive disease mutations by reviewing existing biochemical data on site-directed mutagenesis of the human, Drosophila and yeast Pol γs, and their homologs from the family A DNA polymerase group. We do so in the context of a molecular model of Pol γ in complex with primer-template DNA, which we have developed based upon the recently solved crystal structure of the apoenzyme form. We present evidence that recessive mutations cluster within five distinct functional modules in the catalytic core of Pol γ. Our results suggest that cluster prediction can be used as a diagnosis-supporting tool to evaluate the pathogenic role of new Pol γ variants.
    Nucleic Acids Research 08/2011; 39(21):9072-84. DOI:10.1093/nar/gkr618 · 9.11 Impact Factor
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    Marcos T Oliveira · Laurie S Kaguni ·
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    ABSTRACT: Biochemical studies of the mitochondrial DNA (mtDNA) replisome demonstrate that the mtDNA polymerase and the mtDNA helicase are stimulated by the mitochondrial single-stranded DNA-binding protein (mtSSB). Unlike Escherichia coli SSB, bacteriophage T7 gp2.5 and bacteriophage T4 gp32, mtSSBs lack a long, negatively charged C-terminal tail. Furthermore, additional residues at the N-terminus (notwithstanding the mitochondrial presequence) are present in the sequence of species across the animal kingdom. We sought to analyze the functional importance of the N- and C-terminal regions of the human mtSSB in the context of mtDNA replication. We produced the mature wild-type human mtSSB and three terminal deletion variants, and examined their physical and biochemical properties. We demonstrate that the recombinant proteins adopt a tetrameric form, and bind single-stranded DNA with similar affinities. They also stimulate similarly the DNA unwinding activity of the human mtDNA helicase (up to 8-fold). Notably, we find that unlike the high level of stimulation that we observed previously in the Drosophila system, stimulation of DNA synthesis catalyzed by human mtDNA polymerase is only moderate, and occurs over a narrow range of salt concentrations. Interestingly, each of the deletion variants of human mtSSB stimulates DNA synthesis at a higher level than the wild-type protein, indicating that the termini modulate negatively functional interactions with the mitochondrial replicase. We discuss our findings in the context of species-specific components of the mtDNA replisome, and in comparison with various prokaryotic DNA replication machineries.
    PLoS ONE 10/2010; 5(10):e15379. DOI:10.1371/journal.pone.0015379 · 3.23 Impact Factor
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    Yuichi Matsushima · Yu-ichi Goto · Laurie S Kaguni ·
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    ABSTRACT: Lon is the major protease in the mitochondrial matrix in eukaryotes, and is well conserved among species. Although a role for Lon in mitochondrial biogenesis has been proposed, the mechanistic basis is unclear. Here, we demonstrate a role for Lon in mtDNA metabolism. An RNA interference (RNAi) construct was designed that reduces Lon to less than 10% of its normal level in Drosophila Schneider cells. RNAi knockdown of Lon results in increased abundance of mitochondrial transcription factor A (TFAM) and mtDNA copy number. In a corollary manner, overexpression of Lon reduces TFAM levels and mtDNA copy number. Notably, induction of mtDNA depletion in Lon knockdown cells does not result in degradation of TFAM, thereby causing a dramatic increase in the TFAMmtDNA ratio. The increased TFAMmtDNA ratio in turn causes inhibition of mitochondrial transcription. We conclude that Lon regulates mitochondrial transcription by stabilizing the mitochondrial TFAMmtDNA ratio via selective degradation of TFAM.
    Proceedings of the National Academy of Sciences 10/2010; 107(43):18410-5. DOI:10.1073/pnas.1008924107 · 9.67 Impact Factor

Publication Stats

2k Citations
373.76 Total Impact Points


  • 2012-2015
    • University of Tampere
      • Institute of Biomedical Technology
      Tammerfors, Pirkanmaa, Finland
  • 1986-2014
    • Michigan State University
      • Department of Biochemistry and Molecular Biology
      East Lansing, Michigan, United States
  • 2004-2007
    • Universidad Autónoma de Madrid
      • • Departamento de Bioquímica
      • • Faculty of Medicine
      Madrid, Madrid, Spain
  • 2001
    • Universität Regensburg
      • Lehrstuhl für Entwicklungs- und Kognitionspsychologie
      Ratisbon, Bavaria, Germany
  • 1982-1989
    • Stanford Medicine
      • Department of Biochemistry
      Stanford, California, United States