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Mitochondria

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Articles 31 - 60 of 144

Full-Text Articles in Biology

Therapies For Mitochondrial Disorders, Kayli Sousa Smyth, Anne Mulvihill Dec 2022

Therapies For Mitochondrial Disorders, Kayli Sousa Smyth, Anne Mulvihill

SURE Journal: Science Undergraduate Research Experience Journal

Mitochondria are cytoplasmic, double-membrane organelles that synthesise adenosine triphosphate (ATP). Mitochondria contain their own genome, mitochondrial DNA (mtDNA), which is maternally inherited from the oocyte. Mitochondrial proteins are encoded by either nuclear DNA (nDNA) or mtDNA, and both code for proteins forming the mitochondrial oxidative phosphorylation (OXPHOS) complexes of the respiratory chain. These complexes form a chain that allows the passage of electrons down the electron transport chain (ETC) through a proton motive force, creating ATP from adenosine diphosphate (ADP). This study aims to explore current and prospective therapies for mitochondrial disorders (MTDS). MTDS are clinical syndromes coupled with abnormalities …

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Ankyrin Dependent Mitochondrial Function And Bioenergetics In The Heart, Janani Subramaniam, Janani Subramaniam Dec 2022

Ankyrin Dependent Mitochondrial Function And Bioenergetics In The Heart, Janani Subramaniam, Janani Subramaniam

Dissertations and Theses (Open Access)

ANK2 mutations in patients are associated with numerous arrhythmias, cardiomyopathies, and other heart defects. In the heart, AnkB, the protein encoded by ANK2, clusters relevant ion channels and cell adhesion molecules in several important domains; however, its role at Mitochondria Associated ER/SR Membranes (MAMs) has yet to be investigated. MAMs are crucial to mitochondrial function and metabolism and are signaling hubs implicated in various cardiac pathologies. Among several functions, these sites mediate the direct transfer of calcium from the ER/SR to the mitochondria to modulate ATP synthesis. Given that mitochondrial function and energy production are paramount to cardiovascular heath, …

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Characterization Of Larval Lepidopteran Gut Stem Cell Markers, Zilan Li Jun 2022

Characterization Of Larval Lepidopteran Gut Stem Cell Markers, Zilan Li

All Theses

The larval lepidopteran midgut is a complex tissue system that shows significant structure-function relationships related to its roles in digestive and absorptive processes. δ-endotoxins (Cry toxins) produced by the bacterium Bacillus thuringiensis disrupt the midgut epithelium of target insects has been used extensively to control pests. However, insects, including several lepidopteran species, evolve resistance to Cry toxins which causes a great threat to their continued utility. Understanding the physiology of the midgut, including that of the stem cells which are responsible for midgut growth, development, and regeneration, may improve the sustainability of midgut-targeted control like Cry toxins. Historically, lepidopteran midgut …

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Lis1 And Ndel1 Regulate Axonal Trafficking Of Mitochondria In Mature Neurons, Jai P. Pandey, Liang Shi, Remi A. Brebion, Deanna S. Smith Apr 2022

Lis1 And Ndel1 Regulate Axonal Trafficking Of Mitochondria In Mature Neurons, Jai P. Pandey, Liang Shi, Remi A. Brebion, Deanna S. Smith

Faculty Publications

Defective mitochondrial dynamics in axons have been linked to both developmental and late-onset neurological disorders. Axonal trafficking is in large part governed by the microtubule motors kinesin-1 and cytoplasmic dynein 1 (dynein). Dynein is the primary retrograde transport motor in axons, and mutations in dynein and many of its regulators also cause neurological diseases. Depletion of LIS1, famous for linking dynein deregulation to lissencephaly (smooth brain), in adult mice leads to severe neurological phenotypes, demonstrating post-developmental roles. LIS1 stimulates retrograde transport of acidic organelles in cultured adult rat dorsal root ganglion (DRG) axons but findings on its role in mitochondrial …

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Selection On Dispersal Drives Evolution Of Metabolic Capacities For Energy Production In Female Wing-Polymorphic Sand Field Crickets, Gryllus Firmus, Lisa A. Treidel, Gessen S. Quintanilla Ramirez, Dillon J. Chung, Michael Menze, Jose P. Vazquez-Medina, Caroline M. Williams Mar 2022

Selection On Dispersal Drives Evolution Of Metabolic Capacities For Energy Production In Female Wing-Polymorphic Sand Field Crickets, Gryllus Firmus, Lisa A. Treidel, Gessen S. Quintanilla Ramirez, Dillon J. Chung, Michael Menze, Jose P. Vazquez-Medina, Caroline M. Williams

Faculty and Staff Scholarship

Life history and metabolism covary, but the mechanisms and individual traits responsible for these linkages remain unresolved. Dispersal capability is a critical component of life histories that is constrained by metabolic capacities for energy production. Conflicting relationships between metabolism and life histories may be explained by accounting for variation in dispersal and maximal metabolic rates. We used female wing-polymorphic sand field crickets, Gryllus firmus, selected either for long wings (LW) and flight-capability or short wings (SW) and high early lifetime fecundity to test the hypothesis that selection on dispersal capability drives the evolution of metabolic capacities. While resting metabolic …

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Seasonal Changes In Mitochondrial Bioenergetics And Physiological Performance Of The Bluegill Sunfish, Lepomis Macrochirus, From A Shallow, Midwest River., Derick I. Lamptey, Ryan W. Sparks, Rolando Monte De Oca, Robert Skolik, Michael Menze, Eloy Martinez Jan 2022

Seasonal Changes In Mitochondrial Bioenergetics And Physiological Performance Of The Bluegill Sunfish, Lepomis Macrochirus, From A Shallow, Midwest River., Derick I. Lamptey, Ryan W. Sparks, Rolando Monte De Oca, Robert Skolik, Michael Menze, Eloy Martinez

Faculty and Staff Scholarship

As global temperature shifts due to anthropogenic impacts, the frequency and magnitude of extreme temperatures in shallow aquatic ecosystems are expected to increase. Previous studies performed on fish under fluctuating temperature regimes have reported increased physiological stresses, compared to stable thermal conditions, leading to morphological, behavioral and biochemical adaptations. Moreover, many studies have reported the effects of warmer temperatures on numerous aquatic species, but seasonal temperature changes experienced in aquatic systems are understudied. We surveyed changes in the bioenergetic machinery of a native fish population ( Lepomis macrochirus) in the temperate zone of North America and observed season-dependent thresholds in …

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Analysis Of Mitochondrial Codon Usage, Shelina Begum Jan 2022

Analysis Of Mitochondrial Codon Usage, Shelina Begum

Legacy Theses & Dissertations (2009 - 2024)

The human mitochondrial genome is circular and encodes for its own two ribosomal RNAs, 22 tRNAs and 13 proteins needed for oxidative phosphorylation. Although the mitochondria require nuclear proteins and machinery for transcription and translation, the translation of 13 mRNAs occurs within the mitochondria. The dysregulation of mitochondrial translation is associated with diseases like MELAS (Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes) and MERRF (Myoclonic epilepsy with ragged-red fibers), which can be caused by tRNA defects and lead to decreased translation of mitochondrial complex I proteins (MELAS). We have analyzed the codon usage of human mitochondrial genes and compared them …

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Social Networks In The Single Cell, Moira Rodriguez, Ana Martinez-Hottovy, Alan C. Christensen Jan 2022

Social Networks In The Single Cell, Moira Rodriguez, Ana Martinez-Hottovy, Alan C. Christensen

School of Biological Sciences: Faculty Publications

Plant mitochondrial DNA (mtDNA) can become damaged in many ways. A major repair mechanism is homologous recombination, which requires an undamaged DNA template. Presumably, this template comes from a different mitochondrion in the same cell. Plant mitochondria undergo fission and fusion to form transient networks which could allow the exchange of genetic information. To test this hypothesis, Chustecki et al. (2022) used msh1 mutants with defective DNA repair, and showed that mitochondrial interactions increased, revealing a link between the physical and genetic behavior of mitochondria.

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Chemical And Genetic Analysis Of The Mitochondrial Unfolded Protein Response, Mustafi Raisa Amin Aug 2021

Chemical And Genetic Analysis Of The Mitochondrial Unfolded Protein Response, Mustafi Raisa Amin

Biology Dissertations - Archive

Mitochondria are essential for energy production, metabolic signaling, calcium homeostasis, and other roles. Consequently, mitochondrial dysfunction can result in cellular decline and the onset of disease. Cells use the mitochondrial unfolded protein response (UPRmt) to facilitate the recovery of damaged mitochondria to restore homeostasis. Recent studies have shown that the UPRmt plays a vital role in tumorigenesis and cancer survival. Therefore, UPRmt inhibition may be used as an anticancer strategy with great therapeutic results. Moreover, a known paradigm exists between mitochondrial stress signaling and the regulation of organismal lifespan. Since the UPRmt is activated during mitochondrial stress, it is believed …

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Late Embryogenesis Abundant Proteins And Mitochondrial Membranes From An Animal Extremophile: Insights Into Severe Water Stress, John Marcus Anderson Jul 2021

Late Embryogenesis Abundant Proteins And Mitochondrial Membranes From An Animal Extremophile: Insights Into Severe Water Stress, John Marcus Anderson

LSU Doctoral Dissertations

This dissertation focuses on two major topics germane to mechanisms by which animals tolerate extreme water stress. First, the impact of transgenic expression of late embryogenesis abundant proteins (LEA) on water stress tolerance of the fruit fly Drosophila melanogaster was investigated. The overall aim was to extend current understanding of the protective properties of LEA proteins documented with isolated cells to a desiccation-sensitive organism during exposure to drying and hyperosmotic stress. Four lines of D. melanogaster were created that expressed transgenes encoding selected LEA proteins originally identified in embryos of the extremophile Artemia franciscana. After 80% tissue water loss, …

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Mitochondrial Genome Structure And Double Strand Break Repair In Arabidopsis Thaliana, Sterling Ericsson Jul 2021

Mitochondrial Genome Structure And Double Strand Break Repair In Arabidopsis Thaliana, Sterling Ericsson

School of Biological Sciences: Dissertations, Theses, and Student Research

The mitochondrial genomes of plants are known for their variability in size and arrangement, yet low mutation rates in coding sequences. These opposing characteristics have been suggested to be due to the stability of their DNA maintenance processes and the usage of a double strand break repair (DSBR) system. The components of this repair complex remain poorly understood and only a few of the involved enzymes have been identified, making direct analysis difficult. The flowering plant species Arabidopsis thaliana has been used as a model organism for genome modification and subsequent phenotypic and genotypic impacts. The aims of this research …

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Mitochondrial Distribution Of Glycine Receptors In Motor Neuron Cell Lines, Katsiaryna Milashevich May 2021

Mitochondrial Distribution Of Glycine Receptors In Motor Neuron Cell Lines, Katsiaryna Milashevich

Student Theses and Dissertations

Although non-essential, glycine plays an important role in major metabolic reactions and is most known for its anti-inflammatory effects. An accumulation of contemporary research has shown that glycine is able to stabilize membrane potential using glycine receptors at the cellular level and to protect mitochondrial function directly, whether it is from inflammation, heavy metal poisoning, or ischemia-induced neuroinflammation. In this research, the existence of a hypothetical mitochondrial glycine receptor is examined. Immunofluorescence imaging was used to examine the presence of the glycine receptor subunits alpha 1 and alpha 2 in both non- differentiated and differentiated neuroblastoma cell lines. The preliminary …

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Mitochondrial Oma1 And Opa1 As Gatekeepers Of Organellar Structure/Function And Cellular Stress Response, Robert Gilkerson, Patrick De La Torre, Shaynah St. Vallier Mar 2021

Mitochondrial Oma1 And Opa1 As Gatekeepers Of Organellar Structure/Function And Cellular Stress Response, Robert Gilkerson, Patrick De La Torre, Shaynah St. Vallier

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Mammalian mitochondria are emerging as a critical stress-responsive contributor to cellular life/death and developmental outcomes. Maintained as an organellar network distributed throughout the cell, mitochondria respond to cellular stimuli and stresses through highly sensitive structural dynamics, particularly in energetically demanding cell settings such as cardiac and muscle tissues. Fusion allows individual mitochondria to form an interconnected reticular network, while fission divides the network into a collection of vesicular organelles. Crucially, optic atrophy-1 (OPA1) directly links mitochondrial structure and bioenergetic function: when the transmembrane potential across the inner membrane (ΔΨm) is intact, long L-OPA1 isoforms carry out fusion of the mitochondrial …

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Mitochondrial Opa1 Cleavage Is Reversibly Activated By Differentiation Of H9c2 Cardiomyoblasts, Iraselia Garcia, Fredy Calderon, Patrick De La Torre, Shaynah St. Vallier, Cristobal Rodriguez, Divya Agarwala, Megan Keniry, Wendy Innis-Whitehouse, Robert Gilkerson Mar 2021

Mitochondrial Opa1 Cleavage Is Reversibly Activated By Differentiation Of H9c2 Cardiomyoblasts, Iraselia Garcia, Fredy Calderon, Patrick De La Torre, Shaynah St. Vallier, Cristobal Rodriguez, Divya Agarwala, Megan Keniry, Wendy Innis-Whitehouse, Robert Gilkerson

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Optic atrophy-1 (OPA1) is a dynamin-like GTPase localized to the mitochondrial inner membrane, playing key roles in inner membrane fusion and cristae maintenance. OPA1 is regulated by the mitochondrial transmembrane potential (Δψm): when Δψm is intact, long OPA1 isoforms (L-OPA1) carry out inner membrane fusion. Upon loss of Δψm, L-OPA1 isoforms are proteolytically cleaved to short (S-OPA1) isoforms by the stress-inducible OMA1 metalloprotease, causing collapse of the mitochondrial network and promoting apoptosis. Here, we show that L-OPA1 isoforms of H9c2 cardiomyoblasts are retained under loss of Δψm, despite the presence of OMA1. However, when H9c2s are differentiated to a more …

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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 …

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Identifying New Markers And Mechanisms Of Mitochondrial Defect During Aging, Catherine Chang Sep 2020

Identifying New Markers And Mechanisms Of Mitochondrial Defect During Aging, Catherine Chang

Natural Sciences and Mathematics | Biological Sciences Master's Theses

Mitochondrial dysfunction is a hallmark of aging and has been closely tied to age-related pathologies, such as cancer, cardiovascular diseases, neurodegenerative disorders, and metabolic syndromes. Though the consequences of mitochondrial defects are well documented, little is known about the molecular events that occur with age that transform healthy mitochondria into dysfunctional ones. Past studies have attempted to uncover the underlying proteomic changes in age, however, most of these results do not take into account population heterogeneity often associated with aging, thus highlighting the need for single-cell analysis. Technological barriers have impeded in-depth proteomic studies of aging mitochondria on a single …

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Mitochondrial Morphology, Oxidative Stress Resistance, And Pathogenesis In Cryptococcus Neoformans, Andrew Lee Chang May 2020

Mitochondrial Morphology, Oxidative Stress Resistance, And Pathogenesis In Cryptococcus Neoformans, Andrew Lee Chang

Arts & Sciences Graduate Student Theses and Dissertations

Cryptococcus neoformans is an important pathogen that annually kills 200,000 people worldwide. It survives in the environment as a yeast or spore and can also proliferate within host macrophages after being inhaled into the lungs. In conditions of immunocompromise, cryptococcal cells can escape from the lungs to the brain, where they cause a deadly meningoencephalitis that is both difficult and expensive to treat. Cryptococcal adaptation to the harsh lung environment is a critical first step in its pathogenesis, and consequently a compelling topic of study. This adaptation is mediated by a complex transcriptional program that integrates cellular responses to environmental …

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Parkinson’S Disease: Causes, Symptoms, Research, And Interventions, Alexander Labkowsky Jan 2020

Parkinson’S Disease: Causes, Symptoms, Research, And Interventions, Alexander Labkowsky

The Science Journal of the Lander College of Arts and Sciences

This paper covers several pathogenic theories of Parkinson’s disease (PD); the physiology and biological pathways involved. This includes a mitochondrial DNA (mtDNA) route, a nuclear DNA route, and other hypotheses about idiopathic PD. The subsequent discussion of PD symptoms utilizes a neurological perspective, analyzing the neuroanatomical systems involved, and how they are treated. This includes medications and surgical techniques that are employed in an effort to manage symptomatology and increase health-related quality of life.

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Mitochondrial Dna Repair In An Arabidopsis Thaliana Uracil N-Glycosylase Mutant, Emily L. Wynn, Emma Purfeerst, Alan Christensen Jan 2020

Mitochondrial Dna Repair In An Arabidopsis Thaliana Uracil N-Glycosylase Mutant, Emily L. Wynn, Emma Purfeerst, Alan Christensen

School of Biological Sciences: Faculty Publications

Substitution rates in plant mitochondrial genes are extremely low, indicating strong selective pressure as well as efficient repair. Plant mitochondria possess base excision repair pathways; however, many repair pathways such as nucleotide excision repair and mismatch repair appear to be absent. In the absence of these pathways, many DNA lesions must be repaired by a different mechanism. To test the hypothesis that double-strand break repair (DSBR) is that mechanism, we maintained independent self-crossing lineages of plants deficient in uracil-N-glycosylase (UNG) for 11 generations to determine the repair outcomes when that pathway is missing. Surprisingly, no single nucleotide polymorphisms (SNPs) were …

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Estimating The Age Of A Bloodstain Using Mitochondrial Rrna, Jordan R. Flesher Jan 2020

Estimating The Age Of A Bloodstain Using Mitochondrial Rrna, Jordan R. Flesher

Graduate Theses, Dissertations, and Problem Reports (ETD)

DNA evidence is considered the gold standard of evidence in forensic investigations. DNA is one of the most highly discriminatory pieces of evidence found at crime scenes and can link individuals to scenes. It is not relied on to perform temporal estimates to help establish a timeline for when a crime took place. Previous studies have shown that measurement of the degradation of RNA is a potential tool to establish a temporal estimate of when a blood sample was left at a crime scene. This experiment attempts to improve on previous RNA degradation studies by evaluating the validity of mitochondrial …

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Novel Insights Into The Critical Role Of Cardiolipin In Cellular Metabolism And Mitochondrial Physiology, Jiajia Ji Jan 2020

Novel Insights Into The Critical Role Of Cardiolipin In Cellular Metabolism And Mitochondrial Physiology, Jiajia Ji

Wayne State University Dissertations

Cardiolipin (CL) is the signature phospholipid of mitochondria. CL and its remodeling exert critical roles in biological processes both inside and outside of mitochondria. CL abnormalities have been associated with various mitochondrial disorders and aging. Understanding the role of CL in mitochondrial physiology and cellular metabolism could provide valuable insights into cell biology and human health. Several metabolic alterations have been reported in CL-deficient cells, including accumulated lactate, decreased PDH activity, and decreased TCA cycle function. This dissertation connected these findings by showing abnormal NAD+ metabolism in various models lacking CL. Importantly, it shows that NAD+ supplementation improves mitochondrial function …

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Seasonal Variation In Mitochondrial Bioenergetics Of The Bluegill Sunfish, Lepomis Macrochirus, From A Shallow Midwest River, Derick Isaac Lamptey Jan 2020

Seasonal Variation In Mitochondrial Bioenergetics Of The Bluegill Sunfish, Lepomis Macrochirus, From A Shallow Midwest River, Derick Isaac Lamptey

Masters Theses

As average global temperature increase, the frequency and magnitude of extreme temperatures in shallow aquatic ecosystems are more ubiquitous. In order to understand how these changing thermal regimes affect aquatic ectotherms, it is essential to develop studies evaluating the response of ectotherms to seasonal fluctuating thermal regimes. Previous studies on fluctuating temperature regimes have reported an increased physiological stress leading to morphological, behavioral and biochemical adaptations. From the latter, the adaptive capacity and seasonal performance associated with optimal function of the oxidative phosphorylation system (OXPHOS) are key for species persistence. However, studies on this matter are scarce. This study explores …

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Detection Of Mitochondrial Dna (Mtdna) Mutations, Ali Naini, Robert Gilkerson, Sara Shanske, Jiuhong Pang Jan 2020

Detection Of Mitochondrial Dna (Mtdna) Mutations, Ali Naini, Robert Gilkerson, Sara Shanske, Jiuhong Pang

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

The maternally inherited mitochondrial DNA (mtDNA) is a circular 16,569-bp double stranded DNA that encodes 37 genes, twenty-four of which (2 rRNA and 22 tRNA) are necessary for transcription and translation of 13 polypeptides that are all subunits of respiratory chain. Pathogenic mutations of mtDNA cause respiratory chain dysfunction, and are the underlying defect in an ever-increasing number of mtDNA-related encephalomyopathies with distinct phenotypes. In this chapter, we present an overview of mtDNA mutations and describe the molecular techniques currently employed in our laboratory to detect two types of mtDNA mutations: Single-large scale rearrangements and point mutations.

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Mitochondria Imaging And Targeted Cancer Treatment, Tinghan Zhao Dec 2019

Mitochondria Imaging And Targeted Cancer Treatment, Tinghan Zhao

Dissertations

Mitochondria are essential organelles as the site of respiration in eukaryotic cells and are involved in many crucial functions in cell life. Dysfunction of mitochondrial metabolism and irregular morphology have been frequently found in human cancers. The capability of imaging mitochondria as well as regulating their microenvironment is important both scientifically and clinically. Mitochondria penetrating peptides (MPPs), certain peptides that are composed of cationic and hydrophobic amino acids, are good candidates for mitochondria targeting. Herein, a novel MPP, D-argine-phenylalanine-D-argine-phenylalanine-D-argine-phenylalanine-NH2 (rFrFrF), is conjugated with a rhodamine-based fluorescent chromophore (TAMRA). The TAMRA-rFrFrF probe exhibits advantageous properties for long-term mitochondria tracking of …

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Hypoxia-Inducible Gene Domain 1 Proteins In Yeast Mitochondria Protect Against Proton Leak Through Complex Iv, Ngoc H. Hoang, Vera Strogolova, Jaramys J. Mosley, Rosemary A. Stuart, Jonathan Hosler Nov 2019

Hypoxia-Inducible Gene Domain 1 Proteins In Yeast Mitochondria Protect Against Proton Leak Through Complex Iv, Ngoc H. Hoang, Vera Strogolova, Jaramys J. Mosley, Rosemary A. Stuart, Jonathan Hosler

Biological Sciences Faculty Research and Publications

Hypoxia-inducible gene domain 1 (HIGD1) proteins are small integral membrane proteins, conserved from bacteria to humans, that associate with oxidative phosphorylation supercomplexes. Using yeast as a model organism, we have shown previously that its two HIGD1 proteins, Rcf1 and Rcf2, are required for the generation and maintenance of a normal membrane potential (ΔΨ) across the inner mitochondrial membrane (IMM). We postulated that the lower ΔΨ observed in the absence of the HIGD1 proteins may be due to decreased proton pumping by complex IV (CIV) or enhanced leak of protons across the IMM. Here we measured the ΔΨ generated by complex …

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Multilevel Analysis In Rural Cancer Control: A Conceptual Framework And Methodological Implications, Tine Verreet, Cory J. Weaver, Hiromu Hino, Masahiko Hibi, Fabienne E. Poulain Sep 2019

Multilevel Analysis In Rural Cancer Control: A Conceptual Framework And Methodological Implications, Tine Verreet, Cory J. Weaver, Hiromu Hino, Masahiko Hibi, Fabienne E. Poulain

Faculty Publications

Mitochondria are abundantly detected at the growth cone, the dynamic distal tip of developing axons that directs growth and guidance. It is, however, poorly understood how mitochondrial dynamics relate to growth cone behavior in vivo, and which mechanisms are responsible for anchoring mitochondria at the growth cone during axon pathfinding. Here, we show that in retinal axons elongating along the optic tract in zebrafish, mitochondria accumulate in the central area of the growth cone and are occasionally observed in filopodia extending from the growth cone periphery. Mitochondrial behavior at the growth cone in vivo is dynamic, with mitochondrial positioning …

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The Role Of Mitofusins In The Osteoclast Lineage, Anna Ballard Aug 2019

The Role Of Mitofusins In The Osteoclast Lineage, Anna Ballard

Arts & Sciences Graduate Student Theses and Dissertations

Mitochondria exist in a highly dynamic network in many cell types, and mutations in mitochondrial transmembrane GTPase mitofusin2 (MFN2), a key factor that mediates mitochondrial tethering, cause defects in the nervous system. Intriguingly, the skeleton has been overlooked in patients with such mutations. Because expression of MFN2 and its homolog, mitofusin1 (MFN1) increase with maturation of osteoclasts (OCs), which are rich in mitochondria, we sought to determine the role of mitofusins in the OC lineage. Double knockout of Mfn1 and Mfn2 in OC precursors by Lysozyme-M cre reveals that mitofusin activity is required for OC function and maintenance of bone …

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Electrostatically Localized Proton Bioenergetics: Better Understanding Membrane Potential, James Weifu Lee Jul 2019

Electrostatically Localized Proton Bioenergetics: Better Understanding Membrane Potential, James Weifu Lee

Chemistry & Biochemistry Faculty Publications

In Mitchell's chemiosmotic theory, membrane potential Δψ was given as the electric potential difference across the membrane. However, its physical origin for membrane potential Δψ was not well explained. Using the Lee proton electrostatic localization model with a newly formulated equation for protonic motive force (pmf) that takes electrostatically localized protons into account, membrane potential has now been better understood as the voltage difference contributed by the localized surface charge density ([H-+L] + nΣ i=1 [M(i+)L]) at the liquid-membrane interface as in an electrostatically localized protons/cations-membrane-anions capacitor. That is, the origin of membrane …

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Detection Of Heteroplasmic Single Nucleotide Polymorphisms Using Melt Curve Analysis And Dual Labeled Fluorescent Probes, Emily Jezewski Apr 2019

Detection Of Heteroplasmic Single Nucleotide Polymorphisms Using Melt Curve Analysis And Dual Labeled Fluorescent Probes, Emily Jezewski

Honors Program: Senior Projects (Public)

Plant mitochondrial genomes are strange – they are unusually large, consist of huge amounts of non-coding DNA, and contain of several overlapping regions throughout the genome. The genome is made of several different sized linear and circular molecules and different mitochondria within a cell will have different pieces of the genome. Even if multiple mitochondria contain the same region of the genome, these sequences can differ by single nucleotide polymorphisms (SNPS). This is known as heteroplasmy. Heteroplasmy has been documented in Arabidopsis thaliana using whole-genome sequencing data. While heteroplasmy is well-documented, its existence in the mitochondrial genome is unexpected and …

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Plant Mitochondrial Genome Evolution And Structure Has Been Shaped By Double-Strand Break Repair And Recombination, Emily Wynn Apr 2019

Plant Mitochondrial Genome Evolution And Structure Has Been Shaped By Double-Strand Break Repair And Recombination, Emily Wynn

School of Biological Sciences: Dissertations, Theses, and Student Research

Plant mitochondrial genomes are large but contain a small number of genes. These genes have very low mutation rates, but genomes rearrange and expand at significant rates. We propose that much of the apparent complexity of plant mitochondrial genomes can be explained by the interactions of double-strand break repair, recombination, and selection. One possible explanation for the disparity between the low mutation rates of genes and the high divergence of non-genes is that synonymous mutations in genes are not truly neutral. In some species, rps14 has been duplicated in the nucleus, allowing the mitochondrial copy to become a pseudogene. By …

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