Cell Biology Commons^™

Staphylococcal Nuclease And Ubiquitin Local Folding Energies And Rates Using Peps-Hdx-Esi-Ms, Julie Rhee

Chemistry & Biochemistry Undergraduate Honors Theses

In this study, Protein Equilibrium Population Snapshot Hydrogen-Deuterium Exchange Electrospray Ionization Mass Spectrometry (PEPS-HDX-ESI-MS) was applied to study the local regions of model proteins, staphylococcal nuclease and ubiquitin. The hydrogen deuterium exchange (HDX) has become a key technique for studying the structural and dynamic aspects of proteins in solution. This technique creates a rapid exchange between all of the exchangeable hydrogen ions with deuterium when the protein is exposed to a solvent. The PEPS method is an equilibrium-based method used to determine the populations of the closed native and open denatured states of a protein. By combining the applications of …

Physiology And Genetics Of Starvation-Selected Drosophila Melanogaster, Christopher Michael Hardy

UNLV Theses, Dissertations, Professional Papers, and Capstones

In nature, organisms have evolved to survive in stressful environments. This has driven organisms to adopt a wide range of unique adaptations. Investigating the mechanistic basis of these adaptations is an important tool for discovery that has led to major advances in science and medicine.

We study how organisms survive life without food, or starvational stress. Environmental stressors have shaped the quantity and quality of food sources across the globe. This has led to vast differences in the ability of some organisms to tolerate starvation over others. Many researchers have used Drosophila melanogaster as a model to study global patterns …

In Vitro Investigation Of The Effect Of Exogenous Ubiquitin On Processes Associated With Atherosclerosis, Chase W. Mussard

Undergraduate Honors Theses

Atherosclerosis, characterized by the build-up of cholesterol, immune cells and cellular debris within arterial walls, is accelerated following myocardial infarction by poorly understood mechanisms. Ubiquitin, a small, well-studied intracellular protein involved in protein turnover via the proteasome pathway, has recently been shown to exert extracellular effects on cardiac myocytes, in vitro, and in mice undergoing myocardial remodeling. This study investigates the potential role of extracellular ubiquitin in atherosclerosis by determining its effects on two critical atherosclerotic processes: the migration of vascular smooth muscles cells and the uptake of modified LDL by monocyte/macrophages in foam cell formation. In the presence …

Autophagy Regulation After Diet And Exercise In Non-Alcoholic Fatty Liver Disease, Megan Elizabeth Rosa

Graduate Theses and Dissertations

Along with the rise in obesity, rates of non-alcoholic fatty liver disease (NAFLD) have also increased. NAFLD may begin with fat accumulation in the liver, but can progress to non-alcoholic steatohepatitis (NASH), fibrosis, and eventual cirrhosis. With no pharmacological treatment for NASH, lifestyle interventions appear vital to maintaining liver health. Previous work has shown aberrant mitochondrial content/quality and autophagy in models of NAFLD. Exercise is known to improve mitochondrial health and possibly autophagy, thus autophagy may be a key regulatory factor for treatment of obesity induced-NAFLD. PURPOSE: The purpose of the study was to examine how weight loss from diet …

Nonreplicative Dna Helicases Involved In Maintaining Genome Stability, Salahuddin Syed

USF Tampa Graduate Theses and Dissertations

Double-strand breaks and stalled forks arise when the replication machinery encounters damage from exogenous sources like DNA damaging agents or ionizing radiation, and require specific DNA helicases to resolve these structures. Sgs1 of Saccharomyces cerevisiae is a member of the RecQ family of DNA helicases and has a role in DNA repair and recombination. The RecQ family includes human genes BLM, WRN, RECQL4, RECQL1, and RECQL5. Mutations in BLM, WRN, and RECQL4 result in genetic disorders characterized by developmental abnormalities and a predisposition to cancer. All RecQ helicases have common features including a …

Axonal Transport And Life Cycle Of Mitochondria In Parkinson's Disease Model, Hyun Sung

Open Access Dissertations

In neurons, normal distribution and selective removal of mitochondria are essential for preserving compartmentalized cellular function. Parkin, an E3 ubiquitin ligase associated with familial Parkinson’s disease, has been implicated in mitochondrial dynamics and removal. However, it is not clear how Parkin plays a role in mitochondrial turnover in vivo, and whether the mature neurons possess a compartmentalized Parkin-dependent mitochondrial life cycle. Using the live Drosophila nervous system, here, I investigate the involvement of Parkin in mitochondrial dynamics; organelle distribution, morphology and removal. Parkin deficient animals displayed less number of axonal mitochondria without disturbing organelle motility behaviors, morphology and metabolic state. …

Investigating Ph Banding Kinetics Of Chara Corallina In Alternating Light Conditions With Rectangular Pulse Voltammetry, Matthew C. Zandee

Masters Theses

Chara corallina is an important biological model due to its large internodal cells, the simple shape, and the wide range of techniques that can be used to study it. The alternating acidic and basic banding pattern of Chara corallina upon illumination has been studied and well described over the past several decades. However, much of this complex mechanism is not fully understood. Few studies have shown how the acidic and basic regions have responded in real time as lighting conditions change. Utilizing rectangular pulse voltammetry (RPV) and pH-sensitive carbon microelectrodes along the cell wall allows for a real time profile …

Fipronil Promotes Adipogenesis Via Ampkα-Mediated Pathway In 3t3-L1 Adipocytes, Quancai Sun, Jeremy Yang, Kyong-Sup Yoon, John M. Clark, Yeonhwa Park

SIUE Faculty Research, Scholarship, and Creative Activity

Emerging evidence suggests that organochlorine, organophosphorus and neonicotinoid insecticide exposure may be linked to the development of obesity and type 2 diabetes. However, there is no knowledge of the potential influence of fipronil, which belongs to the phenylpyrazole chemical family, on obesity. Thus, the goal of this study was to determine the role of fipronil in adipogenesis using 3T3-L1 adipocytes. Fipronil treatment, at 10 mM, increased fat accumulation in 3T3-L1 adipocytes as well as promoted key regulators of adipocyte differentiation (CCAAT/enhancer-binding protein α and peroxisome proliferator-activated receptor gamma-γ), and key regulators of lipogenesis (acetyl-CoA carboxylase and fatty acid synthase). The …

Drosophila Models To Investigate The Role Of Regulation Of Cell Death In Development And Cancer, Anam Hussain

Honors Theses

Cell death is of key importance in maintaining health and normal development. In cancer, cell death is improperly controlled provoking uncontrolled proliferation of cells, which results in severe harm to the body. The Hippo pathway is an identified pathway in Drosophila melanogaster that is involved with regulating the different mechanisms of survival and proliferation within the cells. It is known to interact with a gene known as Dronc that is a key participant in the cell death pathway of apoptosis. Previous work has shown how the loss of certain caspases, which are cysteine proteases, is linked with cell survival. My …

Identification Of Potential Drug Targets In Cancer Signaling Pathways Using Stochastic Logical Models, Peican Zhu, Hamidreza Montazeri Aliabadi, Hasan Uludag, Jie Han

Pharmacy Faculty Articles and Research

The investigation of vulnerable components in a signaling pathway can contribute to development of drug therapy addressing aberrations in that pathway. Here, an original signaling pathway is derived from the published literature on breast cancer models. New stochastic logical models are then developed to analyze the vulnerability of the components in multiple signalling sub-pathways involved in this signaling cascade. The computational results are consistent with the experimental results, where the selected proteins were silenced using specific siRNAs and the viability of the cells were analyzed 72 hours after silencing. The genes elF4E and NFkB are found to have nearly no …

Ampa-Kainate Receptor Inhibition Promotes Neurologic Recovery In Premature Rabbits With Intraventricular Hemorrhage, Preeti Dohare, Muhammad T. Zia, Ehsan Ahmed, Asad Ahmed, Vivek Yadala, Praveen Ballabh

NYMC Faculty Publications

Intraventricular hemorrhage (IVH) in preterm infants leads to cerebral inflammation, reduced myelination of the white matter, and neurological deficits. No therapeutic strategy exists against the IVH-induced white matter injury. AMPA-kainate receptor induced excitotoxicity contributes to oligodendrocyte precursor cell (OPC) damage and hypomyelination in both neonatal and adult models of brain injury. Here, we hypothesized that IVH damages white matter via AMPA receptor activation, and that AMPA-kainate receptor inhibition suppresses inflammation and restores OPC maturation, myelination, and neurologic recovery in preterm newborns with IVH. We tested these hypotheses in a rabbit model of glycerol-induced IVH and evaluated the expression of AMPA …

A Functional Bacterium-To-Plant Dna Transfer Machinery Of Rhizobium Etli, Benoît Lacroix, Vitaly Citovsky

Biochemistry & Cell Biology Faculty Publications

Different strains and species of the soil phytopathogen Agrobacterium possess the ability to transfer and integrate a segment of DNA (T-DNA) into the genome of their eukaryotic hosts, which is mainly mediated by a set of virulence (vir) genes located on the bacterial Ti-plasmid that also contains the T-DNA. To date, Agrobacterium is considered to be unique in its capacity to mediate genetic transformation of eukaryotes. However, close homologs of the virgenes are encoded by the p42a plasmid of Rhizobium etli; this microorganism is related toAgrobacterium, but known only as a symbiotic bacterium that …

P-Rex1 Promotes Resistance To Vegf/Vegfr-Targeted Therapy In Prostate Cancer, Hira Lal Goel, Bryan Pursell, Leonard D. Shultz, Dale L. Greiner, Rolf A Brekken, Craig W. Vander Kooi, Arthur M. Mercurio

Molecular and Cellular Biochemistry Faculty Publications

Autocrine VEGF signaling is critical for sustaining prostate and other cancer stem cells (CSCs), and it is a potential therapeutic target, but we observed that CSCs isolated from prostate tumors are resistant to anti-VEGF (bevacizumab) and anti-VEGFR (sunitinib) therapy. Intriguingly, resistance is mediated by VEGF/neuropilin signaling, which is not inhibited by bevacizumab and sunitinib, and it involves the induction of P-Rex1, a Rac GEF, and consequent Rac1-mediated ERK activation. This induction of P-Rex1 is dependent on Myc. CSCs isolated from the PTEN^pc−/− transgenic model of prostate cancer exhibit Rac1-dependent resistance to bevacizumab. Rac1 inhibition or P-Rex1 downregulation increases the …

The Glucose Metabolite Methylglyoxal Inhibits Expression Of The Glucose Transport Genes By Inactivating The Cell Surface Glucose Sensors Rgt2 And Snf3 In Yeast, Adhiraj Roy, Salman Hashmi, Zerui Li, Angela Dement, Kyu Hong Cho, Jeong-Ho Kim

Biochemistry and Molecular Medicine Faculty Publications

Methylglyoxal (MG) is a cytotoxic by-product of glycolysis. MG has inhibitory effect on the growth of cells ranging from microorganisms to higher eukaryotes, but its molecular targets are largely unknown. The yeast cell-surface glucose sensors Rgt2 and Snf3 function as glucose receptors that sense extracellular glucose and generate a signal for induction of expression of genes encoding glucose transporters (HXTs). Here we provide evidence that these glucose sensors are primary targets of MG in yeast. MG inhibits the growth of glucose-fermenting yeast cells by inducing endocytosis and degradation of the glucose sensors. However, the glucose sensors with mutations …

Assembly And Structure Of Human Mitochondrial Transcription Initiation Complex, Yaroslav Morozov

Graduate School of Biomedical Sciences Theses and Dissertations

Mitochondria play a key role in energy metabolism in nearly all eukaryotic cells. Apart from that, they participate in many other biochemical pathways, such as amino acid and nucleotide metabolism, and biosynthesis of cholesterol, heme, and iron-sulfur clusters. Mitochondria are also involved in cell signaling, apoptosis and regulation of cell cycle. Abnormalities of mitochondrial morphology and function are often associated with tumor progression, neurodegeneration and aging.

Mitochondria are unique organelles in mammalian cells because they have their own genomic DNA, transcription and translation systems. Various mutations and defects in mitochondrial gene expression lead to severe diseases that include various mitochondrial …

Shaping The Growth Behaviour Of Biofilms Initiated From Bacterial Aggregates, Gavin Melaugh, Jaime B. Hutchison, Kasper N. Kragh, Yasuhiko Irie, Aled E. L. Roberts, Thomas Bjarnsholt, Stephen P. Diggle, Vernita Gordon, Rosalind J. Allen

Biology Faculty Publications

Bacterial biofilms are usually assumed to originate from individual cells deposited on a surface. However, many biofilm-forming bacteria tend to aggregate in the planktonic phase so that it is possible that many natural and infectious biofilms originate wholly or partially from pre-formed cell aggregates. Here, we use agent-based computer simulations to investigate the role of pre-formed aggregates in biofilm development. Focusing on the initial shape the aggregate forms on the surface, we find that the degree of spreading of an aggregate on a surface can play an important role in determining its eventual fate during biofilm development. Specifically, initially spread …

K14+ Compound Niches Are Present On The Mouse Cornea Early After Birth And Expand After Debridement Wounds., Ahdeah Pajoohesh-Ganji, Sonali Pal-Ghosh, Gauri Tadvalkar, Mary Ann Stepp

Anatomy and Regenerative Biology Faculty Publications

Background: We previously identified compound niches (CNs) at the limbal:corneal border of the mouse cornea that contain corneal epithelial progenitor cells, express Keratin 8 (K8), and goblet cell mucin Muc5AC. During re-epithelialization after 2.5 mm epithelial debridement wounds, CNs migrate onto the cornea and expand in number mimicking conjunctivalization. When CNs form during development and whether they express corneal epithelial progenitor cell enriched K14 was not known.

Results: To provide insight into corneal epithelial homeostasis, we quantify changes in expression of simple (K8, K18, K19) and stratified squamous epithelial keratins (K5, K12, K14, and K15) during postnatal development and in …

Global Regulator Of Virulence A (Grva) Coordinates Expression Of Discrete Pathogenic Mechanisms In Enterohemorrhagic Escherichia Coli Through Interactions With Gadw-Gade, Jason K. Morgan, Ronan K. Carroll, Carly M. Harro, Khoury W Vendura, Lindsey N. Shaw, James T. Riordan

Molecular Biosciences Faculty Publications

UNLABELLED: Global regulator of virulence A (GrvA) is a ToxR-family transcriptional regulator that activates locus of enterocyte effacement (LEE)-dependent adherence in enterohemorrhagic Escherichia coli (EHEC). LEE activation by GrvA requires the Rcs phosphorelay response regulator RcsB and is sensitive to physiologically relevant concentrations of bicarbonate, a known stimulant of virulence systems in intestinal pathogens. This study determines the genomic scale of GrvA-dependent regulation and uncovers details of the molecular mechanism underlying GrvA-dependent regulation of pathogenic mechanisms in EHEC. In a grvA-null background of EHEC strain TW14359, RNA sequencing analysis revealed the altered expression of over 700 genes, including the downregulation …

Decorin As A Multivalent Therapeutic Agent Against Cancer., Thomas Neill, Liliana Schaefer, Renato V. Iozzo

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Decorin is a prototypical small leucine-rich proteoglycan that epitomizes the multifunctional nature of this critical gene family. Soluble decorin engages multiple receptor tyrosine kinases within the target-rich environment of the tumor stroma and tumor parenchyma. Upon receptor binding, decorin initiates signaling pathways within endothelial cells downstream of VEGFR2 that ultimately culminate in a Peg3/Beclin 1/LC3-dependent autophagic program. Concomitant with autophagic induction, decorin blunts capillary morphogenesis and endothelial cell migration, thereby significantly compromising tumor angiogenesis. In parallel within the tumor proper, decorin binds multiple RTKs with high affinity, including Met, for a multitude of oncosuppressive functions including growth inhibition, tumor cell …

Lim Protein Ajuba Participates In The Repression Of Atr-Mediated Dna Damage Response In Human Cells, Sampada Kalan

Dissertations, Theses, and Capstone Projects

LIM proteins constitute a superfamily characterized by the presence of specialized domains called LIM. LIM domain is a unique double-zinc finger motif found in a variety of proteins and is mainly involved in protein-protein interactions. Previous work has implicated that members of the Zyxin subfamily of LIM proteins, namely TRIP6 and LPP are involved in the repression of the DNA damage response (DDR) at telomeres. We further explore if another member from this family has an influence on DDR prevention in the cells. Here, we describe a novel role for Ajuba, a Zyxin family LIM protein, in repressing inappropriate activation …