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Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

Cytochrome B5 Protects Photoreceptors From Light Stress-Induced Lipid Peroxidation And Retinal Degeneration, Xinping Chen, Hana Hall, Jeffrey P. Simpson, Walter D. Leon-Salas, Donald F. Ready, Vikki M. Weake Dec 2017

Cytochrome B5 Protects Photoreceptors From Light Stress-Induced Lipid Peroxidation And Retinal Degeneration, Xinping Chen, Hana Hall, Jeffrey P. Simpson, Walter D. Leon-Salas, Donald F. Ready, Vikki M. Weake

Department of Biochemistry Faculty Publications

Lipid peroxides are generated by oxidative stress in cells, and contribute to ageing and neurodegenerative disease. The eye is at special risk for lipid peroxidation because photoreceptors possess amplified sensory membranes rich in peroxidation-susceptible polyunsaturated fatty acids. Light-induced lipid peroxidation in the retina contributes to retinal degeneration, and lipid peroxidation has been implicated in the progression of age-associated ocular diseases such as age-related macular degeneration (AMD). Here, we show that exposing Drosophila melanogaster to strong blue light induces oxidative stress including lipid peroxidation that results in retinal degeneration. Surprisingly, very young flies are resilient to this acute light stress, suggesting …


An Automated Workflow For Quantifying Rna Transcripts In Individual Cells In Large Data-Sets, Matthew C. Pharris, Tzu-Ching Wu, Xinping Chen, Xu Wang, David M. Umulis, Vikki M. Weake, Tamara L. Kinzer-Ursem Sep 2017

An Automated Workflow For Quantifying Rna Transcripts In Individual Cells In Large Data-Sets, Matthew C. Pharris, Tzu-Ching Wu, Xinping Chen, Xu Wang, David M. Umulis, Vikki M. Weake, Tamara L. Kinzer-Ursem

Department of Biochemistry Faculty Publications

Advanced molecular probing techniques such as single molecule fluorescence in situ hybridization (smFISH) or RNAscope can be used to assess the quantity and spatial location of mRNA transcripts within cells. Quantifying mRNA expression in large image sets usually involves automated counting of fluorescent spots. Though conventional spot counting algorithms may suffice, they often lack high-throughput capacity and accuracy in cases of crowded signal or excessive noise. Automatic identification of cells and processing of many images is still a challenge. We have developed a method to perform automatic cell boundary identification while providing quantitative data about mRNA transcript levels across many …


Another Route For Amino Acid Production?: Reverse Genetic Probing For A Functional Cytosolic Shikimate Pathway In Plants, Gabrielle C. Buck, Joseph Lynch, Natalia Dudareva Aug 2017

Another Route For Amino Acid Production?: Reverse Genetic Probing For A Functional Cytosolic Shikimate Pathway In Plants, Gabrielle C. Buck, Joseph Lynch, Natalia Dudareva

The Summer Undergraduate Research Fellowship (SURF) Symposium

The shikimate pathway is a metabolic pathway that produces the three aromatic amino acids—phenylalanine, tryptophan, and tyrosine—which are essential to human diets and necessary for many plant functions. Consequently, the shikimate pathway is commonly targeted for antibiotic and herbicide strategies as well as genetic engineering in several fields. This pathway is known to be localized in the plastids, or double membrane-bound organelles, of plant cells; however, there is enzymatic evidence of another shikimate pathway in the cell fluid, or cytosol. To determine whether a complete cytosolic shikimate pathway exists, we used a modified gene for the first enzyme of the …


Determining The Structure Of Phospholipase C Epsilon, Hannah O'Neill, Monita Sieng, Elisabeth Garland-Kuntz, Angeline Lyon Aug 2017

Determining The Structure Of Phospholipase C Epsilon, Hannah O'Neill, Monita Sieng, Elisabeth Garland-Kuntz, Angeline Lyon

The Summer Undergraduate Research Fellowship (SURF) Symposium

The phospholipase C (PLC) epsilon subfamily of PLC enzymes are found at highest concentration within the cardiovascular system. Improper functioning of the enzyme, whether due to overstimulation or changes in expression, has far-reaching effects within the human body Stunted heart valve development and cardiac hypertrophy and are two such examples. The mechanisms by which PLC epsilon activity is regulated in these processes remain unknown, as does the physical structure of the enzyme. In this study, we seek to determine the structure of a PLC epsilon fragment that retains enzymatic activity and is amenable to crystallization. Mutagenesis of PLC epsilon cDNA …


Performing A Genetic Screen To Identify Factors That Promote Lncrna-Dependent Gene Repression, Chrishan Fernando, Cecilia Yiu, Sara Cloutier, Siwen Wang, Elizabeth Tran Aug 2017

Performing A Genetic Screen To Identify Factors That Promote Lncrna-Dependent Gene Repression, Chrishan Fernando, Cecilia Yiu, Sara Cloutier, Siwen Wang, Elizabeth Tran

The Summer Undergraduate Research Fellowship (SURF) Symposium

Long non-coding RNAs (lncRNAs) were once thought not to have useful functions in organisms but rather to be products of aberrant transcription. However, roles are being found for lncRNAs in beneficial processes such as controlling gene expression. In some of these cases, lncRNAs form R-loops in vivo. R-loops are nucleic acid structures consisting of hybridized strands of single-stranded DNA (ssDNA) and single-stranded RNA (ssRNA) as well as the displaced strand of ssDNA. Formation of these R-loops is important for gene regulation by the lncRNAs. However, factors that promote formation of lncRNA R-loops are not known. The gene PHO84 is being …


Fret Biosensors: Engineering Fluorescent Proteins As Biological Tools For Studying Parkinson’S Disease, Nathan J. Leroy, Jacob R. Norley, Saranya Radhakrishnan, Mathew Tantama Aug 2017

Fret Biosensors: Engineering Fluorescent Proteins As Biological Tools For Studying Parkinson’S Disease, Nathan J. Leroy, Jacob R. Norley, Saranya Radhakrishnan, Mathew Tantama

The Summer Undergraduate Research Fellowship (SURF) Symposium

Parkinson’s Disease (PD) is a common neurodegenerative disease with over 200,000 new cases each year. In general, the cause of the disease is unknown, but oxidative stress inside of neurons has been associated with the disease’s pathology for some time. Currently, techniques to study the onset of PD inside of neurons are limited. This makes treatments and causes difficult to discover. One solution to this has been fluorescent protein biosensors. In short, these proteins can be engineered to glow when a certain state is achieved inside a cell. The present research discusses the engineering of a genetically-encoded fluorescent protein (FP) …


Fluorescent Protein Biosensor For Use In Parkinson's Research, Piper R. Miller, Keelan Trull, Mathew Tantama Aug 2017

Fluorescent Protein Biosensor For Use In Parkinson's Research, Piper R. Miller, Keelan Trull, Mathew Tantama

The Summer Undergraduate Research Fellowship (SURF) Symposium

Purinergic signaling is a type of extracellular communication that occurs between cells, mediated by adenosine triphosphate (ATP), adenosine diphosphate (ADP), and adenosine. In Parkinson’s Disease, purinergic signaling is disrupted, which contributes to neurodegeneration. In order to monitor this change in cell-to-cell signaling, there is a need for the development of a fluorescent protein (FP) biosensor to study the changes in the concentration of the signaling molecule ATP and its decomposition bioproduct ADP. This summer a genetically encoded ADP sensor that measures changes in ADP concentration was developed. This sensor utilizes Forster Resonance Energy Transfer (FRET) which is a sensing technique …


Determination Of Amino Acids Involved In Specificity And Activity Of Chladub2, Trent S. Arbough, John M. Hausman, Chittaranjan Das Aug 2017

Determination Of Amino Acids Involved In Specificity And Activity Of Chladub2, Trent S. Arbough, John M. Hausman, Chittaranjan Das

The Summer Undergraduate Research Fellowship (SURF) Symposium

Chlamydia trachomatis is a pathogen which infects humans as a sexually transmitted disease or through ocular infection, causing ocular trachoma. Ocular trachoma is the leading cause of non-congenital blindness in developing countries. The bacteria employs the deubiquitinating enzyme ChlaDUB2 to remove ubiquitin from its inclusion membrane in order to avoid lysosomal degradation. Key amino acids involved in ubiquitin recognition and cleavage were mutated in order to probe substrate specificity and catalytic activity of ChlaDUB2. Mutants were used in fluorometry assays in order to determine how the mutations affect the ability of ChlaDUB2 to release the amino methyl coumarin (AMC) group …


Tumor Formation In Response To Loss Of Chromatin Remodeler Chd5 In Zebrafish, Taylor R. Sabato, Erin L. Sorlien, Dr. Joseph P. Ogas Aug 2017

Tumor Formation In Response To Loss Of Chromatin Remodeler Chd5 In Zebrafish, Taylor R. Sabato, Erin L. Sorlien, Dr. Joseph P. Ogas

The Summer Undergraduate Research Fellowship (SURF) Symposium

Chromodomain helicase DNA binding protein 5 (CHD5) has been identified as a tumor suppressor in humans. Deletion or mutation of CHD5 has been observed in numerous cancers, including neuroblastoma and melanoma. We hypothesize that chd5 is also a tumor suppressor in zebrafish, a powerful model system to study tumorigenesis. Many genes involved in tumorigenesis are conserved in zebrafish, and they develop fully penetrant tumor phenotypes. We have created chd5 knock-out zebrafish using CRISPR/Cas9 and are monitoring them for tumor development. In addition to the chd5 knock-outs, we are undertaking a double-mutant approach by coupling loss …


Defining The Destruction Box: Understanding How The Apc Recognizes Its Substrates, Hana Maldivita Tambrin, Mark C. Hall Aug 2017

Defining The Destruction Box: Understanding How The Apc Recognizes Its Substrates, Hana Maldivita Tambrin, Mark C. Hall

The Summer Undergraduate Research Fellowship (SURF) Symposium

Cell division is the process by which mother cells give rise to two genetically identical daughter cells. All cells have protein networks to ensure that cell division is completed correctly because mistakes during cell division may cause diseases. The Anaphase-promoting complex (APC) is an important regulatory enzyme that ensures successful completion of mitosis. It acts by removing inhibitors of chromosomal segregation and cytokinesis, as well as other important cell division regulators. Existing chemotherapies, like taxol, act by indirectly inhibiting APC function. This makes APC a potential target for new cancer chemotherapies. However, designing APC inhibitors is challenging because how APC …


Bacterial Motility And Its Role In Biofilm Formation, Clayton J. Culp, Arezoo M. Ardekani, Adib Ahmadzadegan Aug 2017

Bacterial Motility And Its Role In Biofilm Formation, Clayton J. Culp, Arezoo M. Ardekani, Adib Ahmadzadegan

The Summer Undergraduate Research Fellowship (SURF) Symposium

Bacterial biofilms are known to cause millions of dollars in damage in the medical industry per year via infection of central venous catheters, urinary catheters, and mechanical heart valves. Unfortunately, there are some characteristics of biofilm formation that are yet to be fully understood. Recently much work has been done to investigate the motility characteristics of bacteria with hopes of better understanding the phenomena of biofilm formation. Still, one of the least understood stages is bacterial attachment or adhesion, a process designed to anchor bacteria in an advantageous environment. Providing a better understanding of bacterial motility near solid interfaces will …


Determining The Role Of Epigenetic Factors In Antifungal Drug Resistance, Abigail R. Gress, Scott D. Briggs, Nina Serratore Aug 2017

Determining The Role Of Epigenetic Factors In Antifungal Drug Resistance, Abigail R. Gress, Scott D. Briggs, Nina Serratore

The Summer Undergraduate Research Fellowship (SURF) Symposium

Epigenetic factors are proteins that regulate gene expression by altering transcriptional machinery access to nucleosomes, DNA wrapped around histone proteins. Two classes of epigenetic factors are ATP-dependent chromatin remodelers and histone modifiers such as histone methyltransferases (HMTs), proteins that add methyl groups to histone tails. This study focuses on AIF4 (Antifungal-Induced Factor 4), a possible HMT induced upon neutral lipid depletion that we hypothesize is regulating antifungal drug resistance genes. Overexpression of AIF4 results in hypersensitivity to antifungal drugs. Studying epigenetic factors in the yeast Saccharomyces cerevisiae, including AIF4, can lead to better understanding of cell adaptation to their environments …


A Programmable Optical Stimulator For The Drosophila Eye, Xinping Chen, Walter D. Leon-Salas, Taylor Zigon, Donald F. Ready, Vikki M. Weake Jul 2017

A Programmable Optical Stimulator For The Drosophila Eye, Xinping Chen, Walter D. Leon-Salas, Taylor Zigon, Donald F. Ready, Vikki M. Weake

Department of Biochemistry Faculty Publications

A programmable optical stimulator for Drosophila eyes is presented. The target application of the stimulator is to induce retinal degeneration in fly photoreceptor cells by exposing them to light in a controlled manner. The goal of this work is to obtain a reproducible system for studying age-related changes in susceptibility to environmental ocular stress. The stimulator uses light emitting diodes and an embedded computer to control illuminance, color (blue or red) and duration in two independent chambers. Further, the stimulator is equipped with per-chamber light and temperature sensors and a fan to monitor light intensity and to control temperature. An …