Open Access. Powered by Scholars. Published by Universities.®

Molecular Genetics Commons™

Open Access. Powered by Scholars. Published by Universities.®

Mitochondria

Discipline
Institution
Publication Year
Publication
Publication Type

Articles 1 - 17 of 17

Full-Text Articles in Molecular Genetics

The Role Of Parkin In Mitochondrial Dna, Eliezer Lichter Dec 2022

The Role Of Parkin In Mitochondrial Dna, Eliezer Lichter

Theses & Dissertations

Mitochondria are at the center of biological phenomena such as aging and diseases, especially neurodegenerative diseases. While the discovery of mitochondria only came approximately 200 years after the cell was discovered, a lot of progress has been made since. The mitochondrial genome encodes proteins vital for mitochondrial function. These proteins are only a subset of the proteins present in mitochondria; the rest are nuclear encoded. The nucleus also encodes cytosolic proteins vital for mitochondrial maintenance. One of these is Parkin, an E3 ubiquitin ligase that ubiquitinates mitochondrial proteins as mitochondria become depolarized. Its activity has been shown to be involved …

Go to article

Dpc29 Promotes Mitochondrial Translation Post-Initation In Saccharomyces Cerevisiae, Kyle Andrew Hubble Dec 2022

Dpc29 Promotes Mitochondrial Translation Post-Initation In Saccharomyces Cerevisiae, Kyle Andrew Hubble

Graduate School of Biomedical Sciences Theses and Dissertations

Although the cytosolic and bacterial translation systems are well studied, much less is known about translation in mitochondria. In the yeast Saccharomyces cerevisiae, mitochondrial gene expression is predominately regulated by translational activators. These regulators are thought to promote translation by binding the elongated 5’-UTRs on their target mRNAs. Since mammalian mitochondrial mRNAs generally lack 5’-UTRs, they must regulate translation by other mechanisms. As expected, most yeast translational activators lack orthologues in mammals. Recently, a mitochondrial gene-specific translational activator, TACO1, was reported in mice and humans. To better define its role in mitochondrial translation I examined the yeast TACO1 orthologue, DPC29. …

Go to article

Using Fluorescent Microscopy To Follow Mitochondrial Inheritance Through Tagged Alternative Oxidase In Sporisorium Reilianum., Luke Schroeder May 2022

Using Fluorescent Microscopy To Follow Mitochondrial Inheritance Through Tagged Alternative Oxidase In Sporisorium Reilianum., Luke Schroeder

College of Arts & Sciences Senior Honors Theses

Sporisorium reilianum is a dimorphic fungus that inhabits and infects a host corn plant (Zea mays). In order for the fungus to reproduce sexually, compatible haploid mating types must form a dikaryon that goes on to cause infection in the host. This infection causes leaf chlorosis and gall formation, while ultimately allowing for the dispersal of fungal teliospores in the later stages of infection. To grow, the fungus requires energy production in the form of ATP from its mitochondria. As a countermeasure to infection, host plants release harsh reactive oxygen species that may damage DNA, lead to apoptosis, …

Go to article

Investigation Of Mitochondrial Inheritance In The Smut Fungus Sporisorium Reilianum., Hector Eduardo Mendoza Dec 2021

Investigation Of Mitochondrial Inheritance In The Smut Fungus Sporisorium Reilianum., Hector Eduardo Mendoza

Electronic Theses and Dissertations

An important goal in evolutionary biology is to address the origin of Earth’s immense biodiversity through the evolution of complex sexual reproduction mechanisms in eukaryotes. Inheritance of mitochondria during sexual reproduction has received special attention in recent years, as these organelles cannot be synthesized de novo and must be transmitted from parent to offspring. The importance of these organelles far exceeds its common function as the energy-producing “powerhouse” of the cell, as it has been found to also be involved in fundamental processes like apoptosis, aging and metabolic homeostasis. Thus, appropriate inheritance of mitochondria is essential for growth and development …

Go to article

Growth Of Diatom Fistulifera Alcalina In Bacterial Co-Culture And Comparative Mitogenomics Of Fistulifera Species, Erwin David Berthold Mar 2021

Growth Of Diatom Fistulifera Alcalina In Bacterial Co-Culture And Comparative Mitogenomics Of Fistulifera Species, Erwin David Berthold

FIU Electronic Theses and Dissertations

Diatoms are excellent biological models of growth and intracellular oil generation. The productivity and compounds of diatoms, especially oils, support aquatic food chains and human medical and industrial needs. The qualities that made diatoms prolific producers, specifically diatom physiological features such as growth rates with intracellular lipid storage in alkaline environments, are however poorly understood. Another physiological aspect that remains unexplored is the effects of bacteria on the growth and lipid production of alkaliphilic diatoms. More studies, especially co-cultures, are needed for advances in diatom biology and strain performance for the algal biotechnological field. Besides physiology, diatom genetics using next-generation …

Go to article

Transactivation And Mitochondrial Activity Are Affected By High Temperature In C. Elegans Sperm, Jacqueline Mcvay Jan 2021

Transactivation And Mitochondrial Activity Are Affected By High Temperature In C. Elegans Sperm, Jacqueline Mcvay

Scripps Senior Theses

Sexual reproduction has a conserved flaw in that it is temperature sensitive. Exposure to high temperature leads to male infertility, but little is known about the underlying mechanism. Understanding these mechanisms is important for agriculture and reproductive medicine. Using C. elegans, we investigated two potential aspects of male fertility that may be affected by high temperature conditions: activation of sperm by seminal fluid and sperm mitochondrial activity. There are two pathways for sperm activation in C. elegans: the SPE-8 pathway in hermaphrodites and the TRY-5 pathway in male seminal fluid. Hermaphrodite sperm with a mutation in spe-8 can …

Go to article

The Yeast Protein Mam33 Functions In The Assembly Of The Mitochondrial Ribosome, Gabrielle A Hillman, Michael F Henry Jun 2019

The Yeast Protein Mam33 Functions In The Assembly Of The Mitochondrial Ribosome, Gabrielle A Hillman, Michael F Henry

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

Mitochondrial ribosomes are functionally specialized for the synthesis of several essential inner membrane proteins of the respiratory chain. Although remarkable progress has been made toward understanding the structure of mitoribosomes, the pathways and factors that facilitate their biogenesis remain largely unknown. The long unstructured domains of unassembled ribosomal proteins are highly prone to misfolding and often require dedicated chaperones to prevent aggregation. To date, chaperones that ensure safe delivery to the assembling ribosome have not been identified in the mitochondrion. In this study, a respiratory synthetic lethality screen revealed a role for an evolutionarily conserved mitochondrial matrix protein called Mam33 …

Go to article

Yeast Mitochondrial Protein Pet111p Binds Directly To Two Distinct Targets In Cox2 Mrna, Suggesting A Mechanism Of Translational Activation, Julia L Jones, Katharina B Hofmann, Andrew T Cowan, Dmitry Temiakov, Patrick Cramer, Michael Anikin May 2019

Yeast Mitochondrial Protein Pet111p Binds Directly To Two Distinct Targets In Cox2 Mrna, Suggesting A Mechanism Of Translational Activation, Julia L Jones, Katharina B Hofmann, Andrew T Cowan, Dmitry Temiakov, Patrick Cramer, Michael Anikin

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

The genes in mitochondrial DNA code for essential subunits of the respiratory chain complexes. In yeast, expression of mitochondrial genes is controlled by a group of gene-specific translational activators encoded in the nucleus. These factors appear to be part of a regulatory system that enables concerted expression of the necessary genes from both nuclear and mitochondrial genomes to produce functional respiratory complexes. Many of the translational activators are believed to act on the 5'-untranslated regions of target mRNAs, but the molecular mechanisms involved in this regulation remain obscure. In this study, we used a combination of in vivo and in …

Go to article

A Dedicated Chaperone Mediates The Safe Transfer Of Mitoribosomal Proteins To Their Site Of Assembly, Gabrielle Ashley Hillman May 2019

A Dedicated Chaperone Mediates The Safe Transfer Of Mitoribosomal Proteins To Their Site Of Assembly, Gabrielle Ashley Hillman

Graduate School of Biomedical Sciences Theses and Dissertations

Mitochondrial ribosomes are functionally specialized for the synthesis of several essential inner membrane proteins of the respiratory chain. While remarkable progress has recently been made towards understanding the structure of mitoribosomes, the unique pathways and factors that facilitate their biogenesis remain largely unknown. This dissertation defines the physiological role of an evolutionarily conserved yeast protein called Mam33 in mitochondrial ribosome assembly. The biomedical relevance of this finding stems from the fact that mutations or changes in its expression of the human ortholog p32 result in mitochondrial dysfunction. In human patients, bi-allelic mutations cause severe multisystemic defects in mitochondrial energy metabolism, …

Go to article

Expression Of Alternative Oxidase In The Copepod T. Californicus When Exposed To Environmental Stressors, Carly Tward Jan 2019

Expression Of Alternative Oxidase In The Copepod T. Californicus When Exposed To Environmental Stressors, Carly Tward

Theses and Dissertations (Comprehensive)

In addition to the typical electron transport system in animal mitochondria responsible for oxidative phosphorylation, some species possess an alternative oxidase (AOX) pathway, which causes electrons to bypass proton pumping complexes. Although AOX appears to be energetically wasteful, studies have revealed its wide taxonomic distribution, and indicate it plays a role in environmental stress tolerance. AOX discovery in animals is recent, and further research into its expression, regulation, and physiological role has been impeded by the lack of an experimental model organism. DNA database searches using bioinformatics revealed an AOX sequence present in the arthropod Tigriopus californicus. Multiple sequence …

Go to article

Effects Of Commercial Formulations Of Glyphosate On Saccharomyces Cerevisiae, Apoorva Ravi Shankar Jan 2019

Effects Of Commercial Formulations Of Glyphosate On Saccharomyces Cerevisiae, Apoorva Ravi Shankar

Graduate Theses, Dissertations, and Problem Reports

Commercial formulations of glyphosate are among the most extensively used herbicides around the world. The active ingredient, glyphosate, targets the aromatic amino acid pathway. This pathway is absent in mammals, resulting in low toxicity. Different formulations contain varying adjuvants and surfactants, whose synergistic effects are yet to be extensively studied at the cellular level. In this study, I tested multiple commercial formulations that showed a variation in growth phenotype among different yeast strains. To gain a better understanding of response and resistance mechanisms at the genome and transcriptome level, I carried out an in-lab evolution study, along with a transcriptome …

Go to article

Acetic Acid Induces Sch9p-Dependent Translocation Of Isc1p From The Endoplasmic Reticulum Into Mitochondria, António Rego, Katrina F Cooper, Justin Snider, Yusuf A Hannun, Vítor Costa, Manuela Côrte-Real, Susana R Chaves Jun 2018

Acetic Acid Induces Sch9p-Dependent Translocation Of Isc1p From The Endoplasmic Reticulum Into Mitochondria, António Rego, Katrina F Cooper, Justin Snider, Yusuf A Hannun, Vítor Costa, Manuela Côrte-Real, Susana R Chaves

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

Changes in sphingolipid metabolism have been linked to modulation of cell fate in both yeast and mammalian cells. We previously assessed the role of sphingolipids in cell death regulation using a well characterized yeast model of acetic acid-induced regulated cell death, finding that Isc1p, inositol phosphosphingolipid phospholipase C, plays a pro-death role in this process. Indeed, isc1∆ mutants exhibited a higher resistance to acetic acid associated with reduced mitochondrial alterations. Here, we show that Isc1p is regulated by Sch9p under acetic acid stress, since both single and double mutants lacking Isc1p or/and Sch9p have the same resistant phenotype, and SCH9 …

Go to article

Mechanism Of Transcription Anti-Termination In Human Mitochondria., Hauke S Hillen, Andrey V Parshin, Karen Agaronyan, Yaroslav I Morozov, James J Graber, Aleksandar Chernev, Kathrin Schwinghammer, Henning Urlaub, Michael Anikin, Patrick Cramer, Dmitry Temiakov Nov 2017

Mechanism Of Transcription Anti-Termination In Human Mitochondria., Hauke S Hillen, Andrey V Parshin, Karen Agaronyan, Yaroslav I Morozov, James J Graber, Aleksandar Chernev, Kathrin Schwinghammer, Henning Urlaub, Michael Anikin, Patrick Cramer, Dmitry Temiakov

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

In human mitochondria, transcription termination events at a G-quadruplex region near the replication origin are thought to drive replication of mtDNA by generation of an RNA primer. This process is suppressed by a key regulator of mtDNA-the transcription factor TEFM. We determined the structure of an anti-termination complex in which TEFM is bound to transcribing mtRNAP. The structure reveals interactions of the dimeric pseudonuclease core of TEFM with mobile structural elements in mtRNAP and the nucleic acid components of the elongation complex (EC). Binding of TEFM to the DNA forms a downstream "sliding clamp," providing high processivity to the EC. …

Go to article

Assisted Reproductive Technologies Disrupt Genomic Imprinting In Human And Mitochondria In Mouse Embryos, Carlee R. White Aug 2016

Assisted Reproductive Technologies Disrupt Genomic Imprinting In Human And Mitochondria In Mouse Embryos, Carlee R. White

Electronic Thesis and Dissertation Repository

Infertile couples worldwide use assisted reproductive technologies (ARTs) to help conceive their own biological child. Due to the rising use of ARTs, there is continual emergence of new techniques implemented in human fertility clinics. When treatment is successful, there is an increased risk even within singletons for perinatal complications including preterm birth, intrauterine growth restriction, low and high birth weight and genomic imprinting disorders Beckwith Wiedemann Syndrome, Angelman Syndrome, and Silver-Russel Syndrome. Consequently, there is a need to investigate the effects of these treatments on the manipulated oocyte and preimplantation embryo. To address this, I first analyzed the combined effects …

Go to article

Is A Mitochondrial Plasmid Really A Virus?, Mackenzie Strehle Apr 2016

Is A Mitochondrial Plasmid Really A Virus?, Mackenzie Strehle

UCARE Research Products

In addition to containing a large and complex mitochondrial genome, the mitochondria of several species of plants have been shown to contain an independent, self-replicating DNA molecule in the form of a plasmid. Plants in the Brassica genus contain a linear plasmid that is approximately 11.6 kilobases in length. The plasmid is characterized by the presence of terminal inverted repeats and covalently bonded proteins at its termini (Handa 2008). The plasmid also contains six ORFs that encode DNA and RNA polymerases and a number of unknown proteins (Figure 1). Currently, both the function of this plasmid and the mechanisms by …

Go to article

Functional Significance Of Mtdna Cytosine Modification Tested By Genome Editing, Jason M. Robinson Jan 2016

Functional Significance Of Mtdna Cytosine Modification Tested By Genome Editing, Jason M. Robinson

Theses and Dissertations

The field of epigenetics is gaining popularity and speed, due in part to its capability to answer lingering questions about the root cause of certain diseases. Epigenetics plays a crucial role in regulation of the cell and cell survival, particularly by cytosine methylation. It remains controversial if DNMT’s which facilitate methylation are present in mammalian mitochondria and what the functional significance they may have on modification of mitochondrial DNA. CRISPR-Cas9 technology enabled genome editing to remove the MTS (mitochondrial targeting sequence) from DNMT1 of HCT116 cells, purposefully minimizing effects on nuclear cytosine methylation, while exclusively impacting mitochondrial modification. Removal of …

Go to article

The Toxoplasma Gondii Protein Rop2 Mediates Host Organelle Association With The Parasitophorous Vacuole Membrane, Anthony P. Sinai, Keith A. Joiner Jul 2001

The Toxoplasma Gondii Protein Rop2 Mediates Host Organelle Association With The Parasitophorous Vacuole Membrane, Anthony P. Sinai, Keith A. Joiner

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Toxoplasma gondii replicates within a specialized vacuole surrounded by the parasitophorous vacuole membrane (PVM). The PVM forms intimate interactions with host mitochondria and endoplasmic reticulum (ER) in a process termed PVM–organelle association. In this study we identify a likely mediator of this process, the parasite protein ROP2. ROP2, which is localized to the PVM, is secreted from anterior organelles termed rhoptries during parasite invasion into host cells. The NH2-terminal domain of ROP2 (ROP2hc) within the PVM is exposed to the host cell cytosol, and has characteristics of a mitochondrial targeting signal. In in vitro assays, ROP2hc is …

Go to article