Article
Multidisciplinary Sciences
Amanda A. Riccio, Jonathan Bouvette, Lalith Perera, Matthew J. Longley, Juno M. Krahn, Jason G. Williams, Robert Dutcher, Mario J. Borgnia, William C. Copeland
Summary: In this study, the three-dimensional structures of human Twinkle W315L were determined for the first time using cryo-EM, providing insights into its function in mitochondrial DNA replication and associated diseases. The dynamic movement and molecular consequences of the W315L clinical variant were investigated, shedding light on the mechanism of mitochondrial diseases.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Biochemical Research Methods
Amanda A. Riccio, Jonathan Bouvette, Matthew J. Longley, Juno M. Krahn, Mario J. Borgnia, William C. Copeland
Summary: The mitochondrial replisome is crucial for replicating mtDNA, with Twinkle helicase being a key protein component. Studying SF4 helicases helps understand common themes like self-assembly, ATP-dependent translocation, and formation of protein complexes. The methods described can support future high-resolution studies of Twinkle helicase or other SF4 helicases.
Article
Biochemistry & Molecular Biology
Direnis Erdinc, Bertil Macao, Sebastian Valenzuela, Nicole Lesko, Karin Naess, Bradley Peter, Helene Bruhn, Anna Wedell, Anna Wredenberg, Maria Falkenberg
Summary: Mutations in the catalytic domain of POL? can cause a range of clinical conditions. The p.F907I mutation in POL? leads to a severe clinical phenotype, including developmental arrest and rapid loss of skills. The mutation affects unwinding of parental double-stranded DNA at the replication fork, impairing the ability of POL? to support leading-strand DNA synthesis with the TWINKLE helicase. This study reveals a novel pathogenic mechanism for POL?-related diseases.
BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR BASIS OF DISEASE
(2023)
Article
Cell Biology
Jana Key, Suzana Gispert, Lieke Koornneef, Esther Sleddens-Linkels, Aneesha Kohli, Sylvia Torres-Odio, Gabriele Koepf, Shady Amr, Marina Reichlmeir, Patrick N. Harter, Andrew Phillip West, Christian Muench, Willy M. Baarends, Georg Auburger
Summary: Perrault syndrome is a rare genetic disorder characterized by ovarian insufficiency and hearing loss. CLPP deficiency in mice leads to abnormal meiotic prophase progression and premature cell death. This phenotype is more severe than other mitochondrial related disorders.
Article
Cell Biology
Kathy N. Lam, Peter Spanogiannopoulos, Paola Soto-Perez, Margaret Alexander, Matthew J. Nalley, Jordan E. Bisanz, Renuka R. Nayak, Allison M. Weakley, Feiqiao B. Yu, Peter J. Turnbaugh
Summary: The study demonstrates the use of engineered bacteriophage M13 to deliver DNA to Escherichia coli in the mouse gastrointestinal tract, enabling strain-specific depletion and genomic deletions. Multiple mechanisms allow E. coli to escape targeting, providing a foundation for microbiome editing and suggesting potential for extension to other phage-bacterial pairs.
Article
Biology
Victor Shamanskiy, Alina A. Mikhailova, Evgenii O. Tretiakov, Kristina Ushakova, Alina G. Mikhailova, Sergei Oreshkov, Dmitry A. Knorre, Natalia Ree, Jonathan B. Overdevest, Samuel W. Lukowski, Irina Gostimskaya, Valerian Yurov, Chia-Wei Liou, Tsu-Kung Lin, Wolfram S. Kunz, Alexandre Reymond, Ilya Mazunin, Georgii A. Bazykin, Jacques Fellay, Masashi Tanaka, Konstantin Khrapko, Konstantin Gunbin, Konstantin Popadin
Summary: This study reveals that the contact zone between two direct repeats on mitochondrial DNA is a hot spot for deletions, which may be associated with human aging. The direct repeats within the contact zone are more likely to cause mutations compared to repeats outside the zone. These findings have important implications for predicting mutation burden and maximum lifespan in human populations and mammalian species.
Article
Neurosciences
Margalida Puigr, Anna Calderon, Alexandra Perez-Soriano, Cristina de Dios, Manel Fernandez, Anna Colell, Maria-Jose Marti, Eduardo Tolosa, Ramon Trullas
Summary: Mitochondrial dysfunction occurs in both idiopathic (iPD) and LRRK2-related Parkinson's disease (LRRK2-PD), but previous studies have suggested different types of mitochondrial pathology in the two disorders. A novel multiplex digital PCR assay was developed to quantify cell-free mitochondrial DNA (cf-mtDNA) copy number and deletion ratio in cerebrospinal fluid (CSF). The results showed significant differences in cf-mtDNA content and deletion levels between iPD and LRRK2-PD, supporting the hypothesis of distinct mitochondrial pathophysiology in these diseases.
NEUROBIOLOGY OF DISEASE
(2022)
Article
Neurosciences
Margalida Puigros, Anna Calderon, Alexandra Perez-Soriano, Cristina de Dios, Manel Fernandez, Anna Colell, Maria-Jose Marti, Eduardo Tolosa, Ramon Trullas
Summary: This study found differences in the content and deletion ratio of cf-mtDNA in the cerebrospinal fluid of patients with iPD and LRRK2-PD, suggesting different mitochondrial pathophysiology between these two forms of Parkinson's disease.
NEUROBIOLOGY OF DISEASE
(2022)
Article
Cell Biology
Vlad-Julian Piljukov, Sirelin Sillamaa, Tiina Sedman, Natalja Garber, Margus Ratsep, Arvi Freiberg, Juhan Sedman
Summary: Irc3 is a mitochondrial helicase in Saccharomyces cerevisiae that has been suggested to play a role in both DNA metabolic processes and mRNA translation. However, the modest thermostability of the S. cerevisiae protein has limited in vitro analysis. In this study, a homologous helicase from the thermotolerant yeast Ogataea polymorpha (Irc3op) was purified, which retained its structural integrity and catalytic activity at temperatures above 40 degrees C. Irc3op could complement the respiratory deficiency phenotype of a S. cerevisiae irc3 Delta mutant, indicating conservation of biochemical functions. The ATPase activity of Irc3op was best stimulated by branched and double-stranded DNA cofactors, and had lower but detectable stimulation with RNA molecules possessing a compact three-dimensional structure. These findings suggest that Irc3 might have dual specificity and remodel both DNA and RNA molecules in vivo.
Article
Multidisciplinary Sciences
Pierre R. Bushel, James Ward, Adam Burkholder, Jianying Li, Benedict Anchang
Summary: The interplay between genetic variants in the nuclear and mitochondrial genomes plays a crucial role in breast cancer development, affecting the size of cell nuclei and the risk of mortality.
SCIENTIFIC REPORTS
(2022)
Article
Cell Biology
Daniela Bebbere, Susanne E. Ulbrich, Katrin Giller, Valeri Zakhartchenko, Horst-Dieter Reichenbach, Myriam Reichenbach, Paul J. Verma, Eckhard Wolf, Sergio Ledda, Stefan Hiendleder
Summary: The study reveals about 50% reduction in mitochondrial DNA (mtDNA) in the liver and skeletal muscle of SCNT fetuses at day 80 of gestation, with no significant decrease observed in the brain. The depletion of mtDNA is associated with hepatomegaly and muscle hypertrophy of SCNT fetuses, indicating that it is a major signature of perturbations after SCNT. The expression of selected nuclear-encoded genes pivotal for mtDNA replication is similar to controls, suggesting that the mitochondrial perturbation in interaction with incomplete nuclear reprogramming drives abnormal epigenetic features and correlated phenotypes.
FRONTIERS IN CELL AND DEVELOPMENTAL BIOLOGY
(2021)
Article
Genetics & Heredity
Arianna Manini, Leonardo Caporali, Megi Meneri, Simona Zanotti, Daniela Piga, Ignazio Giuseppe Arena, Stefania Corti, Antonio Toscano, Giacomo Pietro Comi, Olimpia Musumeci, Valerio Carelli, Dario Ronchi
Summary: This article describes two cases of mitochondrial DNA maintenance disorders characterized by progressive external ophthalmoplegia, ptosis, and muscle weakness. Sequencing analysis revealed different mutations in the RNASEH1 gene in these patients.
FRONTIERS IN GENETICS
(2022)
Article
Cell Biology
Alessia Nasca, Andrea Legati, Megi Meneri, Melisa Emel Ermert, Chiara Frascarelli, Nadia Zanetti, Manuela Garbellini, Giacomo Pietro Comi, Alessia Catania, Costanza Lamperti, Dario Ronchi, Daniele Ghezzi
Summary: This study reports the identification of biallelic ENDOG variants in a patient with progressive external ophthalmoplegia, mitochondrial myopathy, and multiple mtDNA deletions in muscle. The absence of the ENDOG protein and the presence of multiple mtDNA deletions indicate the pathogenicity of the identified variants. The accumulation of low-level heteroplasmic mtDNA point mutations suggests a possible role of ENDOG in mtDNA replication or repair.
Article
Genetics & Heredity
Yuri A. Zarate, Katherine A. Bosanko, Mary Ann Thomas, David T. Miller, Kristina Cusmano-Ozog, Antonio Martinez-Monseny, Cynthia J. Curry, John M. Graham, Lea Velsher, Mir Reza Bekheirnia, Veronica Seidel, Demitrios Dedousis, Anna L. Mitchell, Amy M. DiMarino, Angelika Riess, Meena Balasubramanian, Jennifer L. Fish, Aisling R. Caffrey, Nicole Fleischer, Tyler Mark Pierson, Ronald Lacro
Summary: SATB2-Associated syndrome (SAS) is a neurodevelopmental disorder caused by alterations in SATB2 at 2q33.1. Individuals with Delta SAS often exhibit underweight, progressive decline in weight and height, facial dysmorphism, and unique facial features compared to non-Delta SAS individuals. Additionally, Delta SAS individuals have increased risks for aortic root/ascending aorta dilation and primary pulmonary hypertension due to specific gene deletions. Care recommendations for individuals with Delta SAS variants are provided based on these findings.
Article
Biochemistry & Molecular Biology
Mario K. Shammas, Yu Nie, Alexandra Gilsrud, Xiaoping Huang, Derek P. Narendra, Patrick F. Chinnery
Summary: Mutations in the mitochondrial intermembrane space protein CHCHD10 can cause different clinical phenotypes. In this study, we investigated whether the mutations lead to mitochondrial DNA deletions and found that the deletion levels were higher in mutant mice compared to wild-type mice, depending on the Chchd10 genotype and age. We also observed that the spinal cord was less prone to mtDNA deletions. Furthermore, the mutations led to the accumulation of a novel set of deletions characterized by shorter direct repeats flanking the deletion breakpoints. These findings suggest that tissue-specific deletions induced by Chchd10 mutations may contribute to the clinical phenotype in humans.
HUMAN MOLECULAR GENETICS
(2023)