Biochemistry, Biophysics, and Structural Biology Commons^™

Alanyl-Trna Synthetase Quality Control Prevents Global Dysregulation Of The Escherichia Coli Proteome, Paul Kelly, Nicholas Backes, Kyle Mohler, Christopher Buser, Arundhati Kavoor, Jesse Rinehart, Gregory Phillips, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Mechanisms have evolved to prevent errors in replication, transcription, and translation of genetic material, with translational errors occurring most frequently. Errors in protein synthesis can occur at two steps, during tRNA aminoacylation and ribosome decoding. Recent advances in protein mass spectrometry have indicated that previous reports of translational errors have potentially underestimated the frequency of these events, but also that the majority of translational errors occur during ribosomal decoding, suggesting that aminoacylation errors are evolutionarily less tolerated. Despite that interpretation, there is evidence that some aminoacylation errors may be regulated, and thus provide a benefit to the cell, while others …

Mechanisms That Limit Oxidative Phosphorylation During High-Intensity Muscle Contractions In Vivo, Miles F. Bartlett

Doctoral Dissertations

Skeletal muscle oxidative capacity plays a critical role in human health and disease. Although current models of oxidative phosphorylation sufficiently describe skeletal muscle energetics during moderate-intensity contractions, much is still unknown about the mechanisms that control and limit oxidative phosphorylation during high-intensity contractions. In particular, the oxygen cost of force generation is augmented during exercise at workloads above the lactate threshold. Presently, it is unclear whether this augmentation in muscle oxygen consumption is driven by increased rates of oxidative ATP synthesis (ATP_OX) or by decreases in the efficiency of ATP_OX due to mitochondrial uncoupling. To address this …

The Effects Of Acidosis On Calcium Dependent Binding Of A Single Crossbridge, Matthew Unger

Masters Theses

Intracellular acidosis is a putative agent of skeletal muscle fatigue, in part, because acidosis depresses the calcium (Ca²⁺) sensitivity and force production of muscle (18, 50). However, the molecular mechanisms behind this depression in Ca²⁺ sensitivity and force production are unknown. This gap in knowledge poses a significant challenge in generating a complete understanding of the fatigue process. To close this gap, the ability of myosin to bind to a single actin filament was measured under acidic conditions, in a laser trap assay, with and without regulatory proteins. Decreasing pH from 7.4 to 6.5 reduced the frequency …

The Fitness Landscape Of The African Salmonella Typhimurium St313 Strain D23580 Reveals Unique Properties Of The Pbt1 Plasmid, Rocío Canals, Roy R. Chaudhuri, Rebecca E. Steiner, Siân V. Owen, Natalia Quinones-Olvera, Melita A. Gordon, Michael Baym, Michael Ibba, Jay C. D. Hinton

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

We have used a transposon insertion sequencing (TIS) approach to establish the fitness landscape of the African Salmonella enterica serovar Typhimurium ST313 strain D23580, to complement our previous comparative genomic and functional transcriptomic studies. We used a genome-wide transposon library with insertions every 10 nucleotides to identify genes required for survival and growth in vitro and during infection of murine macrophages. The analysis revealed genomic regions important for fitness under two in vitro growth conditions. Overall, 724 coding genes were required for optimal growth in LB medium, and 851 coding genes were required for growth in SPI-2-inducing minimal medium. These …

Excess No Stabilizes The Luminal Domain Of Stim2 In A Cys-Specific Manner Thereby Regulating Basal Calcium Homeostasis And Store-Operated Calcium Entry, Matthew Novello

Electronic Thesis and Dissertation Repository

Stromal-interaction molecule 2 (STIM2) is an endoplasmic reticulum (ER) membrane-inserted Ca²⁺-sensing protein which, together with the plasma membrane Ca²⁺ channel Orai1, regulates basal Ca²⁺ homeostasis and store-operated Ca²⁺ entry (SOCE). Recent evidence suggests that S-nitrosylation, which is the covalent attachment of a nitric oxide (NO) moiety to a cysteine thiol, can attenuate the function of the paralog STIM1 protein. Compared to STIM1, STIM2 also functions as a basal Ca²⁺ homeostatic feedback regulator. Therefore, the objective of my study was to evaluate the susceptibility of STIM2 to S-nitrosylation and the effects that this …

Inhibition Of Mitochondrial Permeability Transition By Deletion Of The Ant Family And Cypd, Jason Karch, Michael J. Bround, Hadi Khalil, Michelle A. Sargent, Nadina Latchman, Naohiro Terada, Pablo M. Peixoto, Jeffery D. Molkentin

Publications and Research

The mitochondrial permeability transition pore (MPTP) has resisted molecular identification. The original model of the MPTP that proposed the adenine nucleotide translocator (ANT) as the inner membrane pore-forming component was challenged when mitochondria from Ant1/2 double null mouse liver still had MPTP activity. Because mice express three Ant genes, we reinvestigated whether the ANTs comprise the MPTP. Liver mitochondria from Ant1, Ant2, and Ant4 deficient mice were highly refractory to Ca2+-induced MPTP formation, and when also given cyclosporine A (CsA), the MPTP was completely inhibited. Moreover, liver mitochondria from mice with quadruple deletion of Ant1, Ant2, Ant4, and Ppif (cyclophilin …

Assessing The Structure-Function Relationships Of The Apolipoprotein(A) Kringle Iv Sub-Type 10 Domain, Matthew J. Borrelli

Electronic Thesis and Dissertation Repository

Elevated plasma lipoprotein(a) (Lp(a)) is the most prevalent heritable risk factor in the development of cardiovascular disease. The apolipoprotein(a) (apo(a)) component of Lp(a) is strongly implicated in the pathogenicity of Lp(a). It is hypothesized that the inflammatory potential of Lp(a)/apo(a) is mediated by the lysine binding ability of the apo(a) kringle IV10 (KIV10) domain, along with its covalently bound oxidized phospholipid (oxPL). Using targeted mutagenesis, two novel null alleles for the LPA gene that generate non-secretable apo(a) species have been identified, resulting from amino acid substitutions in the KIV10 domain. A potential mechanism by which KIV10 oxPL modification is enriched …

Translational Control Of Antibiotic Resistance, Anne Witzky, Rodney Tollerson Ii, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Many antibiotics available in the clinic today directly inhibit bacterial translation. Despite the past success of such drugs, their efficacy is diminishing with the spread of antibiotic resistance. Through the use of ribosomal modifications, ribosomal protection proteins, translation elongation factors and mistranslation, many pathogens are able to establish resistance to common therapeutics. However, current efforts in drug discovery are focused on overcoming these obstacles through the modification or discovery of new treatment options. Here, we provide an overview for common mechanisms of resistance to translation-targeting drugs and summarize several important breakthroughs in recent drug development.

Tracing Nutrient Sources To Lipid Production In Insects Using Stable Isotope (Δ13c, Δ2h) Tracers: Implications For Nutritional Physiology Of Migratory Species., Libesha Anparasan, Keith A. Hobson

Western Research Forum

Using stable isotope measurements of insect tissues to determine origin and migratory patterns is well established. However, isotopically determining nutritional origins of lipids, the primary fuel of migration, has not been as thoroughly researched. We explored isotopic links between diet and stored lipids in laboratory raised True armyworm moths (Mythimna unipuncta) using δ¹³C and δ²H measurements. Pupae were randomly separated into four groups (n=20) and fed isotopically distinct nectar, each consisting of a combination of high δ¹³C (C4 sugar), or low δ¹³C (C3 sugar) carbohydrate, with high δ²H (deuterium spiked), …

Evolutionary Expansions And Neofunctionalization Of Ionotropic Glutamate Receptors In Cnidaria, Ellen G. Dow

FIU Electronic Theses and Dissertations

Reef ecosystems are composed of a variety of organisms, transient species of fish and invertebrates, microscopic bacteria and viruses, and structural organisms that build the living foundation, coral. Sessile cnidarians, corals and anemones, interpret dynamic environments of organisms and abiotic factors through a molecular interface. Recognition of foreign molecules occurs through innate immunity via receptors identifying conserved molecular patterns. Similarly, chemosensory receptors monitor the environment through specific ligands. Chemosensory receptors include ionotropic glutamate receptors (iGluRs), transmembrane ion channels involved in chemical sensing and neural signal transduction. Recently, an iGluR homolog was implicated in cnidarian immunological resistance to recurrent infections of …

Development Of A Sonically Powered Biodegradable Nanogenerator For Bone Regeneration, Avi S. Patel

University Scholar Projects

Background: Reconstruction of bone fractures and defects remains a big challenge in orthopedic surgery. While regenerative engineering has advanced the field greatly using a combination of biomaterial scaffolds and stem cells, one matter of difficulty is inducing osteogenesis in these cells. Recent works have shown electricity’s ability to promote osteogenesis in stem cell lines when seeded in bone scaffolds; however, typical electrical stimulators are either (a) externally housed and require overcomplex percutaneous wires be connected to the implanted scaffold or (b) implanted non-degradable devices which contain toxic batteries and require invasive removal surgeries.

Objective: Here, we establish a biodegradable, piezoelectric …

Development Of A Sonically Powered Biodegradable Nanogenerator For Bone Regeneration, Avi Patel

Honors Scholar Theses

Background: Reconstruction of bone fractures and defects remains a big challenge in orthopedic surgery. While regenerative engineering has advanced the field greatly using a combination of biomaterial scaffolds and stem cells, one matter of difficulty is inducing osteogenesis in these cells. Recent works have shown electricity’s ability to promote osteogenesis in stem cell lines when seeded in bone scaffolds; however, typical electrical stimulators are either (a) externally housed and require overcomplex percutaneous wires be connected to the implanted scaffold or (b) implanted non-degradable devices which contain toxic batteries and require invasive removal surgeries.

Objective: Here, we establish a biodegradable, piezoelectric …

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, …

Extracellular Vesicles As Biological Shuttles For Targeted Therapies., Stefania Raimondo, Gianluca Giavaresi, Aurelio Lorico, Riccardo Alessandro

College of Osteopathic Medicine (TUN) Publications and Research

The development of effective nanosystems for drug delivery represents a key challenge for the improvement of most current anticancer therapies. Recent progress in the understanding of structure and function of extracellular vesicles (EVs)-specialized membrane-bound nanocarriers for intercellular communication-suggests that they might also serve as optimal delivery systems of therapeutics. In addition to carrying proteins, lipids, DNA and different forms of RNAs, EVs can be engineered to deliver specific bioactive molecules to target cells. Exploitation of their molecular composition and physical properties, together with improvement in bio-techniques to modify their content are critical issues to target them to specific cells/tissues/organs. Here, …

Relación Entre La Grasa Subcutánea Y Desempeño Maternal En Vacas Angus Primerizas, Esteban Mendoza De La Pava, Adel David Kalil Rey

Zootecnia

El objetivo del presente estudio, tuvo como finalidad lograr identificar el porcentaje de grasa dorsal que se moviliza en vacas Angus primerizas posterior al parto y cómo este podría verse relacionado con el desempeño maternal y el peso al destete del ternero. Para poder lograr este objetivo, se evaluaron doce vacas primerizas de la raza Angus del CIC (centro de investigación y capacitación) San Miguel en Facatativá, Cundinamarca, con diversos parámetros productivos como: peso corporal, puntaje de condición corporal del preparto y al destete, espesor de grasa dorsal (preparto y destete), espesor de grasa en el anca (preparto y destete), …

Alternative Nad(P)H Dehydrogenase And Alternative Oxidase: Proposed Physiological Roles In Animals, Allison Mcdonald, Dmytro V. Gospodaryov

Biology Faculty Publications

The electron transport systems in mitochondria of many organisms contain alternative respiratory enzymes distinct from those of the canonical respiratory system depicted in textbooks. Two of these enzymes, the alternative NADH dehydrogenase and the alternative oxidase, were of interest to a limited circle of researchers until they were envisioned as gene therapy tools for mitochondrial disease treatment. Recently, these enzymes were discovered in several animals. Here, we analyse the functioning of alternative NADH dehydrogenases and oxidases in different organisms. We propose that both enzymes ensure bioenergetic and metabolic flexibility during environmental transitions or other conditions which may compromise the operation …

Antisense Oligonucleotides Targeting Angiotensinogen: Insights From Animal Studies, Chia-Hua Wu, Ya Wang, Murong Ma, Adam E. Mullick, Rosanne M. Crooke, Mark J. Graham, Alan Daugherty, Hong S. Lu

Saha Cardiovascular Research Center Faculty Publications

Angiotensinogen (AGT) is the unique substrate of all angiotensin peptides. We review the recent preclinical research of AGT antisense oligonucleotides (ASOs), a rapidly evolving therapeutic approach. The scope of the research findings not only opens doors for potentially new therapeutics of hypertension and many other diseases, but also provides insights into understanding critical physiological and pathophysiological roles mediated by AGT.

Of Course, Humans Are Not Unique!, Bernard Wallner

Animal Sentience

This commentary focuses on the question of the uniqueness of humans in comparison to other species and on the false assumption that single arguments support logical conclusions. Comparative analysis of genetic data in humans and nonhuman primates regarding the dopaminergic system of the subcortical mesolimbic reward system highlights homologous traits shared and modified by the process of evolution. Such an analytical approach is more relevant than claims of uniqueness.

Data Collection Curated With An Application Ontology Describes The Methods And Results Upon Performing An Ex-Vivo Voltage-Clamp Assay On Outer Hair Cells Of The Mammalian Cochlea, Brenda Farrell, Jason Bengtson

Research Data

This data collection describes the electrical properties of outer hair cells isolated from the mammalian cochlea of the domestic guinea pig. This data was obtained by performing whole-cell patch clamp voltage clamp assay on cells and monitoring the electrical admittance during a DC voltage ramp. The membrane capacitance was then calculated at each membrane potential from this admittance, and the voltage-independent and voltage-dependent membrane capacitance was determined upon further analysis. In some case the DC conductance was also measured by interrogation of the cell with voltage-step function which was calculated from the change in the mean steady-state current with respect …

Effects Of Tumor-Related Factors And Chemotherapy On Skeletal Muscle And The Protective Effects Of Exercise, Blas Anselmo Guigni

Graduate College Dissertations and Theses

Cancer patients often experience cachexia, a form of weight loss consisting mostly of skeletal muscle wasting. Muscle wasting leads to physical disability, poor quality of life, reduced tolerance to treatments and shorter survival. Although the causes of cancer-related muscle atrophy have been studied for decades, the exact mechanisms through which cancer and its treatments promote muscle wasting have yet to be defined.

The overall aim of this dissertation is to examine the mediators of muscle wasting in cancer patients during their treatment and examine the modulatory role of exercise to maintain muscle size and function. To address these aims, we …

Effects Of Aquatic Acidification On Calcium Uptake In White River Shrimp Litopenaeus Setiferus Gills, Maria-Flora Jacobs

UNF Graduate Theses and Dissertations

Previous research regarding aquatic acidification has examined the protonation of the carbonate and does not consider calcium to be a limiting factor. This is the first study to suggest that pH may affect the uptake of calcium in crustacean gills. This project describes ion transport mechanisms present in the cell membranes of white river shrimp Litopenaeus setiferus gill epithelium, and the effects of pH on the uptake of calcium by these means. Partially purified membrane vesicles (PPMV) of shrimp gills were prepared through a homogenization process that has been used previously to define ion transport in crab and lobster gill …

The Balance Between Prostaglandin E2 Ep3 And Ep4 Receptors Determines Severity Of Cardiac Damage In Myocardial Infarction And An Angiotensin Ii-Induced Model Of Hypertension, Timothy Dean Bryson

Wayne State University Dissertations

According to the center for disease control about 610,000 people die every year in the United States from heart disease, of which, coronary heart disease is the most common form. One major risk factor for heart attack is hypertension, which affects nearly half of all Americans [472, 473]. PGE2 plays an important role in regulating cardiovascular function and mediating inflammation, both of which contribute to the development of hypertension and/or heart disease. Prostaglandin E2 can act as a vasodilator or vasoconstrictor depending on which of its receptor subtypes are activated.

In general, activation of the EP1 and EP3 receptors is …

The Relationship Between Seasonal Breeding And Deiodinase Expression In The Green Anole Lizard, Hyejoo Kang

All Graduate Theses, Dissertations, and Other Capstone Projects

Reproductive physiology and behavior is mainly regulated by the hypothalamus-pituitary-gonad (HPG) axis. Interestingly, abnormal levels of thyroid hormone (TH) results in the delayed onset of puberty and affects gonadal function of adults by altering HPG axis activity. Seasonally breeding animals undergo drastic hormonal and behavioral changes between breeding and non-breeding seasons. Green anole lizards (Anolis carolinensis), similar to other seasonally breeding animals, have increased sex steroid hormones, larger gonads, upregulated gonadal steroidogenic acute regulatory protein (StAR) mRNA and increased reproductive behavior during the breeding compared to non-breeding seasons. Relatively less is known regarding the regulation of gonadal TH in seasonal …

Electrostatic Networks And Mechanisms Of Δph-Dependent Gating In The Human Voltage-Gated Proton Channel Hv1, Ashley L. Bennett

Theses and Dissertations

The structure of the voltage-gated proton (H⁺) channel Hv1 is homologous to the voltage sensor domain (VSD) of tetrameric voltage-gated Na⁺, K⁺ and Ca²⁺ channels (VGCs), but lacks a pore domain and instead forms a homodimer. Similar to other VSD proteins, Hv1 is gated by changes in membrane potential (V), but unlike VGCs, voltage-dependent gating in Hv1 is modulated by changes in the transmembrane pH gradient (DpH = pH_o - pH_i). In Hv1, pH_o or pH_i changes shift the open probability (P_OPEN)-V relation by ~40 mV per …

Development Of A Biomarker Panel For Identifying Stressed Marine Mammals, Laura Pujade

University of the Pacific Theses and Dissertations

Increasing anthropogenic disturbance in marine ecosystems such as fishing, oil-drilling, and noise pollution can have detrimental effects on the reproduction and survival of apex predators such as marine mammals. Stress activates the hypothalamic-pituitary-adrenal (HPA) axis, resulting in increased circulating glucocorticoid (GCs) hormones, which alter expression of target genes encoding metabolic enzymes and other mediators of stress. Prolonged HPA axis stimulation may increase catabolism of nutrient stores and suppress immune and reproductive functions, impacting the fitness of marine mammals. GCs measurements are used to identify wild animals experiencing stress. However, these measurements may not be sensitive enough to distinguish between an …