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Full-Text Articles in Molecular Biology

Mechanisms Of Telomere Maintenance In Trypanosoma Brucei, M A G G. Rabbani May 2022

Mechanisms Of Telomere Maintenance In Trypanosoma Brucei, M A G G. Rabbani

ETD Archive

Telomeres are a nucleoprotein structure at the end of the chromosome and are essential for genome integrity and chromosome stability. Telomere lengths are primarily maintained by a telomerase-mediated pathway but can be maintained by a homologous recombination-mediated pathway. However, detailed mechanisms of telomere maintenance are still unclear in many eukaryotes, including an important human pathogen, Trypanosoma brucei. Telomeres can be elongated by telomerase in T. brucei, a causative agent of fatal sleeping sickness in humans and nagana in cattle. T. brucei evades host immune response by regularly switching its major surface antigen, variant surface glycoprotein (VSG), a process known as …


High And Low Toxin Producing Strains Of Karenia Brevis Differ Significantly In The Redox Proteome, Lipid Profiles, And Xanthophyll Cycle Pigments, Ricardo Colon Jun 2021

High And Low Toxin Producing Strains Of Karenia Brevis Differ Significantly In The Redox Proteome, Lipid Profiles, And Xanthophyll Cycle Pigments, Ricardo Colon

FIU Electronic Theses and Dissertations

The dinoflagellate Karenia brevis, blooms annually in the Gulf of Mexico, producing a suite of neurotoxins known as the brevetoxins. The cellular toxin content of K. brevis, however, is highly variable between or even within strains. I investigated biochemical differences between high (KbHT) and low (KbLT) toxin producing cultures both derived from the Wilson strain, related to energy-dependent quenching (qE) by photosystem II, and the content of reduced thiols of the proteome. By characterizing the xanthophyll content of the two strains I was able to determine that KbLT performs qE inconsistently. To investigate the …


Development Of Linked-Domain Protein Inhibitors Of The E2-Conjugating Enzyme Ube2d, Anneroos E. Nederstigt Jan 2021

Development Of Linked-Domain Protein Inhibitors Of The E2-Conjugating Enzyme Ube2d, Anneroos E. Nederstigt

University of the Pacific Theses and Dissertations

In most eukaryotic organisms, the ubiquitination pathway is one of the most important and versatile signaling systems in use. It is integral to processes such as protein degradation and homeostasis, DNA repair cell cycle regulation, signaling and regulation, epigenetics, and many more. Ubiquitin (Ub) is a short polypeptide of 8.6 kDa, 76 residues that functions as a reversible post-translation modification (PTM). It furthermore contains 7 different lysine residues (K6, K11, K27, K29, K33, K48, K63), all of which can form isopeptide linkages with one another to link individual Ub moieties to form unique polyUb chains onto substrates. The type of …


Determining A Method For Expressing And Purifying Cytochrome P450 4v2: A Protein Involved In Bietti's Crystalline Dystrophy, Cody Lane Turner Dec 2020

Determining A Method For Expressing And Purifying Cytochrome P450 4v2: A Protein Involved In Bietti's Crystalline Dystrophy, Cody Lane Turner

MSU Graduate Theses

Within the Cytochrome P450 class of enzymes, there are a group known as the “orphan” cytochromes. The “orphan” classification comes from the poorly understood in vivo functionality and substrate specificity. Cytochrome P450 4V2 (CYP4V2) is one of these “orphans” and belongs to the CYP4 family. The CYP4 family is known for the omega oxidation of endogenous fatty acids. This family is most commonly found on chromosome 1 (CYP4ABXZ). CYP4V2 is unique in that its location is bound to chromosome 4 as discovered by Jiao in 2004. Mutations within the CYP4V2 gene have been associated with the …


Iron-Sulfur Cluster Assembly; In Vivo Analysis Of The Methanogenic Suf System, Evan Dunkle Aug 2019

Iron-Sulfur Cluster Assembly; In Vivo Analysis Of The Methanogenic Suf System, Evan Dunkle

LSU Master's Theses

Iron-sulfur (Fe-S) clusters are among the most ancient and prevalent of all biological cofactors. Their assembly into associated proteins is a tightly regulated process with many organisms employing multiple cluster assembly pathways. Much is known about Fe-S cluster assembly in aerobic organisms such as Escherichia coli (E. coli) but little is known in regards to cluster assembly in more ancient organisms such as methanogens. Methanogens are members of the domain of Archaea and are defined by their ability to generate methane as a byproduct of their main energy generating pathway. Methanogens also have significantly higher Fe-S cluster content …


Evaluating Methods Of Obtaining Male Pheromone From Hymenochirus Sp. Using Analytical Chemistry, Vincent Wing-Kun Leung Jan 2019

Evaluating Methods Of Obtaining Male Pheromone From Hymenochirus Sp. Using Analytical Chemistry, Vincent Wing-Kun Leung

University of the Pacific Theses and Dissertations

Male Hymenochirus sp. frogs are known to release pheromone that attracts females of the same species. Four methods for collecting secretions containing pheromone in Hymenochirus sp. were tested: norepinephrine injection, gonadotropin-releasing hormone injection, homogenization of gland tissue, and electrostimulation of the skin over the breeding gland area. The samples collected were analyzed using high-performance liquid chromatography (HPLC) and mass spectrometry. The HPLC chromatograph for the male norepinephrine sample contained a peak at 6.4 min that was not in the female norepinephrine sample HPLC chromatograph. The male norepinephrine sample mass spectrum had a peak of m/z 292.0 not in the female …


A Multisession, Undergraduate Molecular Biology Lab Experiment Using Green Fluorescent Protein Including Subcloning And Color Changing Mutagenesis, Nathan S. Winter Apr 2018

A Multisession, Undergraduate Molecular Biology Lab Experiment Using Green Fluorescent Protein Including Subcloning And Color Changing Mutagenesis, Nathan S. Winter

Chemistry Faculty Publications

This paper describes a series of experiments involving handling and manipulating the DNA coding for Green Fluorescent Protein (GFP) including the subcloning of this gene, and mutating the DNA so that Cyan Fluorescent Protein (CFP) or Blue Fluorescent protein (BFP) are expressed. The primers needed for the PCR based subcloning of GFP are presented, as are those needed to mutate the GFP to either CFP or BFP.


Clinical Light Exposure, Photoreceptor Degeneration, And Ap-1 Activation: A Cell Death Or Cell Survival Signal In The Rhodopsin Mutant Retina?, Danian Gu, William Beltran, Zexiao Li, Gregory M. Acland, Gustavo D. Aguirre Feb 2016

Clinical Light Exposure, Photoreceptor Degeneration, And Ap-1 Activation: A Cell Death Or Cell Survival Signal In The Rhodopsin Mutant Retina?, Danian Gu, William Beltran, Zexiao Li, Gregory M. Acland, Gustavo D. Aguirre

Gustavo D. Aguirre, VMD, PhD

PURPOSE. The T4R RHO mutant dog retina shows retinal degeneration with exposures to light comparable to those used in clinical eye examinations of patients. To define the molecular mechanisms of the degeneration, AP-1 DNA-binding activity, composition, posttranslational modification of the protein complex, and modulation of ERK/MAPK signaling pathways were examined in light-exposed mutant retinas. METHODS. Dark-adapted retinas were exposed to short-duration light flashes from a retinal camera used clinically for retinal photography and were collected at different time points after exposure. Electrophoretic mobility shift assay (EMSA), supershift EMSA, Western blot analysis, and immunocytochemistry were used to examine AP-1 signaling. RESULTS. …


Bestrophin Gene Mutations Cause Canine Multifocal Retinopathy: A Novel Animal Model For Best Disease, Karina E. Guziewicz, Barbara Zangerl, Sarah J. Lindauer, Robert F. Mullins, Lynne S. Sandmeyer, Bruce H. Grahn, Edwin M. Stone, Gregory M. Acland, Gustavo D. Aguirre Feb 2016

Bestrophin Gene Mutations Cause Canine Multifocal Retinopathy: A Novel Animal Model For Best Disease, Karina E. Guziewicz, Barbara Zangerl, Sarah J. Lindauer, Robert F. Mullins, Lynne S. Sandmeyer, Bruce H. Grahn, Edwin M. Stone, Gregory M. Acland, Gustavo D. Aguirre

Gustavo D. Aguirre, VMD, PhD

PURPOSE. Canine multifocal retinopathy (cmr) is an autosomal recessive disorder of multiple dog breeds. The disease shares a number of clinical and pathologic similarities with Best macular dystrophy (BMD), and cmr is proposed as a new large animal model for Best disease. METHODS. cmr was characterized by ophthalmoscopy and histopathology and compared with BMD-affected patients. BEST1 (alias VMD2), the bestrophin gene causally associated with BMD, was evaluated in the dog. Canine ortholog cDNA sequence was cloned and verified using RPE/choroid 5′- and 3′-RACE. Expression of the canine gene transcripts and protein was analyzed by Northern and Western blotting and immunocytochemistry. …


Characterization Of A Phosphonate-Specific Cytidylyltransferase, Kissa Batul Jan 2016

Characterization Of A Phosphonate-Specific Cytidylyltransferase, Kissa Batul

Theses and Dissertations (Comprehensive)

Antibiotic resistance is a major global health concern that requires new therapeutic approaches. Furthermore, a lack of narrow spectrum antibiotics on the market produces unintended consequences with respect to changes in our microbial make up. Phosphonates are reduced versions of phosphates that possess a C-P bond which is more resistant to enzymatic and chemical degradation. The role of phosphonate containing macromolecules (e.g. cell surface polysaccharides) remains enigmatic, however their presence suggests that they may confer an advantage. The biosynthesis of phosphonate-containing macromolecules is unknown, but a pathway is proposed involving aLicC type cytidylyltransferase-catalyzed conjugation to a phosphonate followed by a …


Reverse Gyrase Is Not Necessary For Survival Of Hyperthermophilic Archaeon Pyrococcus Furiosus, Farshid Taghizadeh, Michael S. Bartlett May 2015

Reverse Gyrase Is Not Necessary For Survival Of Hyperthermophilic Archaeon Pyrococcus Furiosus, Farshid Taghizadeh, Michael S. Bartlett

Student Research Symposium

Reverse gyrase is the only known topoisomerase enzyme with positive supercoiling activity on covalently-closed DNA. This positive supercoiling is required to prevent DNA from denaturation at high temperatures. The gene that codes for this protein is present in all hyperthermophiles and absent from all mesophilic and thermophilic genomes, suggesting that this enzyme is the only hyperthermophile-specific protein. To investigate if this protein is vital for the cells, we knocked out its gene from the genome of living organism Pyrococcus furiosus. Pyrococcus furiosus is a hyperthermophilic archaeon that grows between 70°C to 103°C with an optimum growth temperature of 100°C. …


Core Concepts In Biochemistry And Molecular Biology In An Integrated Mbbs Curriculum, M P. Iqbal Apr 2004

Core Concepts In Biochemistry And Molecular Biology In An Integrated Mbbs Curriculum, M P. Iqbal

Department of Biological & Biomedical Sciences

No abstract provided.


The Influence Of A Human Repetitive Dna On Genome Stability, Eugenia L. Posey May 1998

The Influence Of A Human Repetitive Dna On Genome Stability, Eugenia L. Posey

Electronic Theses and Dissertations

A uniquely human interspersed repetitive DNA sequence family, the L2Hs, are highly polymorphic in human genomes. Several features of interspersed repeated DNA may contribute to the instability observed. Certain motifs (direct repeats, palindromes, and inverted repeats) comprising L2Hs elements may adopt unusual secondary structures such as cruciforms or hairpins. These motifs have been associated with features of genome instability in recombination, insertions and deletions. The L2Hs elements also are AT-rich (76%) compared to the bulk of human DNA (52%). That their dynamic nature (i.e. polymorphisms) may arise from recombination, insertions and deletions has led to the hypothesis that the L2Hs …


Endogenous Alkylglycerol Functions As A Mediator Of Protein Kinase C Activity And Cell Proliferation, Fritz G. Buchanan May 1997

Endogenous Alkylglycerol Functions As A Mediator Of Protein Kinase C Activity And Cell Proliferation, Fritz G. Buchanan

Electronic Theses and Dissertations

To explore the possibility that 1-O-alkyl-sn-glycerol (alkylglycerol) may serve a regulatory role in the control of cell proliferation or PKC activity, we examined the ability of alkylglycerol to influence PKC activity and subcellular distribution as well as the ability of alkylglycerol to effect cell proliferation. MDCK cells grown to confluence show a loss of PKC activity associated with the membrane, as reported in fibroblasts. Preconfluent cultures of MDCK cells have a high level of PKC activity associated with the membrane. However, treatment of preconfluent cultures with alkylglycerol causes a reduction of PKC activity. A similar inhibition was observed with alkylglycerol …


A Molecular Basis For Erythromycin Sensitivity And Resistance In Escherichia Coli, Harold S. Chittum Dec 1993

A Molecular Basis For Erythromycin Sensitivity And Resistance In Escherichia Coli, Harold S. Chittum

Electronic Theses and Dissertations

The effect of erythromycin on the 50S ribosomal subunit during cell growth has been extensively investigated. Sucrose density gradient analysis of ribosomes formed in the presence and absence of the drug revealed a 50S specific assembly defect is partially responsible for erythromycin's inhibitory effects on wild type cells. Examination of two erythromycin-resistant mutants of E. coli (N281 and N282) revealed that mutant N281 (L22 mutant) but not N282 (L4 mutant) was assembly defective in the presence of the drug, although only at much higher drug concentrations (300 ug/ml vs. 75 ug/ml for wild type cells). The altered genes from each …


Mouse Mast Cell Proteases: Induction, Molecular Cloning, And Characterization, Wei Chu May 1991

Mouse Mast Cell Proteases: Induction, Molecular Cloning, And Characterization, Wei Chu

Electronic Theses and Dissertations

Tryptase, a mast cell-specific serine protease with trypsin-like specificity, has been identified in a mouse mast cell line (ABFTL-6) based on it's enzymatic activity, inhibition properties, and cross-reactivity to a human mast cell tryptase antibody. The effects of fibroblast-conditioned medium and sodium butyrate on ABFTL-6 mast cell differentiation and tryptase expression have been examined. ABFTL-6 mouse mast cells undergo phenotypic changes upon culturing in media supplemented with fibroblast-conditioned media at 50% or 1 mM sodium butyrate. The induced cells increased in size, had larger and more metachromatic cytoplasmic granules, and increased their total cellular protein about four-fold. Tryptase activity increased …


A Temperature-Sensitive Mutant Of Escherichia Coli Affected In The Alpha Subunit Of Rna Polymerase, Majid Mehrpouyan Dec 1990

A Temperature-Sensitive Mutant Of Escherichia Coli Affected In The Alpha Subunit Of Rna Polymerase, Majid Mehrpouyan

Electronic Theses and Dissertations

A temperature-sensitive mutant of Escherichia coli affected in the alpha subunit of RNA polymerase has been investigated. Gene mapping and complementation experiments placed the mutation to temperature-sensitivity within the alpha operon at 72 min on the bacterial chromosome. The rate of RNA synthesis in vivo and the accumulation of ribosomal RNA were significantly reduced in the mutant at 44$\sp\circ$C. The thermostability at 44$\sp\circ$C of the purified holoenzyme from mutant cells was about 20% of that of the normal enzyme. Assays with T7 DNA as a template showed that the fraction of active enzyme competent for transcription was reduced as a …