Biology Commons^™

Towards A New Role Of Mitochondrial Hydrogen Peroxide In Synaptic Function, Cliyahnelle Z. Alexander

Student Theses and Dissertations

Aerobic metabolism is known to generate damaging ROS, particularly hydrogen peroxide. Reactive oxygen species (ROS) are highly reactive molecules containing oxygen that have the potential to cause damage to cells and tissues in the body. ROS are highly reactive atoms or molecules that rapidly interact with other molecules within a cell. Intracellular accumulation can result in oxidative damage, dysfunction, and cell death. Due to the limitations of H₂O₂ (hydrogen peroxide) detectors, other impacts of ROS exposure may have been missed. HyPer7, a genetically encoded sensor, measures hydrogen peroxide emissions precisely and sensitively, even at sublethal levels, during …

Methamphetamine-Induced Dna Double-Stranded Breaks: The Impact Of The Dopamine Transporter And Insights Into The Mechanisms Of Dna Damage In Mouse Neuro 2a Cells, Lizette Couto

Dissertations, Theses, and Capstone Projects

Methamphetamine (METH) abuse remains a global health concern, with emerging evidence highlighting its genotoxic potential. In the central nervous system METH enters dopaminergic cells primarily through the dopamine transporter (DAT), which controls the dynamics of dopamine (DA) neurotransmission by driving the reuptake of extracellular DA into the presynaptic neuronal cell. Additional effects of METH on the storage of DA in synaptic vesicles lead to the dysregulated cytosolic accumulation of DA. Previous studies have shown that after METH disrupts intracellular vesicular stores of DA, the excess DA in the cytosol is rapidly oxidized. This generates an abundance of reactive oxygen species …

Examining Transcriptional Regulators During Muscle Development In Drosophila Melanogaster, Chaamy Yapa

Student Theses and Dissertations

In Drosophila melanogaster embryos, a distinct approach to study the transcriptional regulation is to examine the larval somatic muscle development. Transcription factors are essential regulatory proteins that help to control gene expression and respond to signaling pathways and various cues. Today, there are at least twenty transcription factors that have been discovered to contribute to the development of the 30 distinct larval somatic muscles in each abdominal hemisegment of Drosophila melanogaster. Several studies have already been conducted on muscle regulatory transcription factors including midline and apterous. These transcription factors were shown to control the development of muscles through mutant …

Function Of Atm And Msh2 During Dna Repair And Recombination, Emily Sible

Dissertations, Theses, and Capstone Projects

Class switch recombination (CSR) produces secondary immunoglobulin isotypes and requires AID-dependent DNA deamination of intronic switch (S) regions within the immunoglobulin heavy chain (Igh) gene locus. Non-canonical repair of deaminated DNA by mismatch repair (MMR) or base excision repair (BER) creates DNA breaks that permit recombination between distal S regions. ATM-dependent phosphorylation of AID at serine-38 (pS38-AID) promotes its interaction with APE1, a BER protein, suggesting that ATM regulates CSR through BER. However, pS38-AID may also function in MMR during CSR, although the mechanism remains unknown. To examine whether ATM modulates BER- and/or MMR-dependent CSR, Atm^-/- mice …

Nup211 Plays An Important Role In Regulating Mrna Export And Stress Response, Ayana Ikenouchi

Theses and Dissertations

Nup211 is a nuclear pore basket component in Schizosaccharomyces pombe and roles in the gating functions of NPCs. Using RT-qPCR, I found that in nup211-shutoff cells, the transcript levels of genes in mRNA export and stress-response pathways were significantly changed, suggesting nup211 is involved in regulating stress response pathways.

The Central Dogma: Gene Expression, Ayisha Sookdeo

Open Educational Resources

In this lesson plan, students will learn the basic structure and function of DNA and RNA. They will also learn the process of gene expression. Finally, students will learn about the scientific contributor, Ernest Everest Just, and his contributions to the field of Biology.

The Structural And Functional Role Of Photosensing In Rgs-Lov Proteins, Zaynab Jaber

Dissertations, Theses, and Capstone Projects

Light provides organisms with energy and spatiotemporal information. To survive and adapt, organisms have developed the ability to sense light to drive biochemical effects that underlie vision, entrainment of circadian rhythm, stress response, virulence, and many other important molecularly driven responses. Blue-light sensing Light-Oxygen-Voltage (LOV) domains are ubiquitous across multiple kingdoms of life and modulate various physiological events via diverse effector domains. Using a small molecule flavin chromophore, the LOV domain undergoes light-dependent structural changes leading to activation or repression of these catalytic and non-catalytic effectors. In silico analyses of high-throughput genomic sequencing data has led to the marked expansion …

Molecular Mechanisms Underlying Cell Fate Choice Within Specific Retinal Lineages, Estie Schick

Dissertations, Theses, and Capstone Projects

During development, retinal progenitor cells (RPCs) divide to form all of the cell types that make up the retina. Multipotent RPCs are competent to generate all retinal cell types, while restricted RPCs form specific lineages of cells. In particular, one genetically-defined RPC type preferentially gives rise to cone photoreceptors and horizontal cells. Many of the mechanisms that are responsible for directing cell fate choice within this lineage are unknown. This thesis largely focuses on examining the development of specific cell types and subtypes from restricted RPCs and on investigating the gene regulatory events that underlie cone photoreceptor and horizontal cell …

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 …

Protein Phosphatase 2a Suppresses Spindle Elongation In Saccharomyces Cerevisiae, Shoily P. Khondker

Dissertations, Theses, and Capstone Projects

Eukaryotic cell division is an essential process that is carried out by the cell cycle, a tightly controlled process that has been extensively studied in the budding yeast Saccharomyces cerevisiae. The cell cycle is driven by Cyclin Dependent Kinase (Cdk1) activity. Protein phosphatase 2A-Cdc55 (PP2A^Cdc55) reverses Cdk1 phosphorylation events during late stages of the cell cycle to ensure the correct order of events. This thesis presents evidence that the anaphase inhibitor Pds1 is a PP2A^Cdc55 target. Pds1 binds to and inhibits separase (Esp1). Esp1 triggers sister chromatid segregation by cleaving the cohesin complex that holds the …

Through The Back Door: Proteins Escape Cells Without Conventional Permission, Michael J. Cohen

Dissertations, Theses, and Capstone Projects

Proteins secreted to the extracellular environment play a fundamental role as signals, in metabolism, and a variety of other processes. The process of secretion through the endoplasmic reticulum and Golgi to the plasma membrane is well documented, and all cargo in this pathway contains a signal peptide. However, a variety of proteins secreted from eukaryotes lack a signal peptide and are called unconventionally secreted proteins. Here we discuss known mechanisms of unconventional protein secretion, as well as model proteins which follow characterized pathways. Additionally, we summarize the roles various unconventionally secreted proteins play outside of cells and suggest criteria for …

Fetal Pig Dissection Manual (Biol 105), Nathalia G. Holtzman, Daniel J. Yakubov

Open Educational Resources

This book is a guide to the basic fetal pig dissection conducted as a part of the Queens College, CUNY Biology Department Bio105 General Biology: Physiology and Cell Biology course. This course is the first half our two-part series for biology majors. The actives are designed to be conducted over a three- 3-hour lab periods which focus on the relationship of form and function of the pig anatomy and physiology. Step by step instructions for the dissection are provided along with some microscopy tasks to look at the histology of key organs.

In addition to the full text of the …

Histology Atlas: Basic Mammalian Tissue Types (Biol 105), Joshua Barnes, Daniel J. Yakubov, Corinna Singleman, Nathalia G. Holtzman

Open Educational Resources

This book is a guide to the basic histology lab conducted as a part of the Queens College, CUNY Biology Department Bio105 General Biology: Physiology and Cell Biology course. This course is the first half our two-part series for biology majors. The actives are designed to be conducted over a single 3-hour lab periods which focus on the relationship of form and function of the cellular and organ level anatomy and physiology. Step by step instructions for each slide set are provided for all the key organs.

In addition to the full text of the book, we also provide a …

The 5-Ht1a-R Knockout Mouse As A Model Of Later Life Anxiety Disorders: Implications For Sex Differences, Tatyana Budylin

Dissertations, Theses, and Capstone Projects

Anxiety affects nearly twice as many women as it affects men across all cultures and economic groups. Importantly, girls have a higher chance of inheriting anxiety disorders than boys, and many anxiety disorders appear at a very young age. However, little is known about sex differences in brain and behavioral development and how they relate to anxiety in adulthood. Serotonin 1A receptor (5-HT_1A-R) mediated signaling has been implicated in depression and anxiety, however most studies that focus on the involvement of the 5-HT_1A-R have been conducted in adults. Little is known about how the 5-HT_{1A …}

The Role And Regulation Of Alternative Polyadenylation In The Dna Damage Response, Michael R. Murphy

Dissertations, Theses, and Capstone Projects

Cellular homeostasis is achieved by the dynamic flux in gene expression. Post-transcriptional regulation of coding and non-coding RNA offers a fast method of adapting to a changing cellular environment, including deadenylation, microRNA (miRNA) pathway, and alternative polyadenylation (APA). In this dissertation, I explored some of the mechanisms involved in the post-transcriptional regulation of gene expression. The main hypothesis in these studies is that a single APA event after DNA damage is governed by specific conditions and factors outside of current known regulators of APA, and that the resultant transcript has a role in the DNA damage response (DDR). My aims …

The Molecular Mechanisms Underlying The Cancer Killing Effect Of Interleukin-24, Leah Eshanie Persaud

Dissertations, Theses, and Capstone Projects

Interleukin-24 (IL-24) is an immunomodulatory cytokine that also displays specific anti-tumor effects across many cancer cell types. The tumor suppressor activities of IL-24 include inhibition of angiogenesis, metastasis, toxic autophagy, cancer-specific apoptosis, and sensitization to traditional cancer treatments like chemotherapy and radiation. Overexpression of IL-24 can selectively induce apoptosis in various cancer cells while having no adverse effects on normal cells. Due to this favorable killing effect, IL-24 is currently in phase II clinical trials. There is accumulating evidence that IL-24’s anti-cancer activity is primarily through the endoplasmic reticulum (ER) stress pathway but other pathways leading to cell death are …

Regulation Of The Tubulin Homolog Ftsz In Escherichia Coli, Monika S. Buczek

Dissertations, Theses, and Capstone Projects

Escherichia coli is a well-known pathogen, and importantly, a widely used model organism in all fields of biological sciences for cloning, protein purification, and as a model for Gram-negative bacterial species. And yet, researchers do not fully understand how this bacterium replicates and divides. Every year additional division proteins are discovered, which adds complexity to how we understand E. coli undergoes cell division. Due to their specific roles in cytokinesis, some of these proteins may be potential targets for development of antibacterials or bacteriostatics, which are much needed for fighting the current global antibacterial deficit. My thesis work focuses on …

Zero Textbook Cost Syllabus For Bio 3005 (Molecular And Cellular Biology), Krista Dobi, Kim Macklin

Open Educational Resources

The biology of cells is examined with an emphasis on the relationship between organelle structure and function. Activity of the nucleus, cell structure, division and growth, and tools for studying genes will be discussed. Laboratory experiments are performed with isolated organelles or intact cells. Techniques include cell fractionation, bio-chemical assays, and DNA isolation and modification. Students will also read and analyze articles from scientific journals.

Substitutions In Conserved Regions Preceding And Within The Linker Affect Activity And Flexibility Of Trnase Zl, The Long Form Of Trnase Z, Makensie Saoura, Kyla Pinnock, Maria Pujantell-Graell, Louis Levinger

Publications and Research

The enzyme tRNase Z, a member of the metallo-β-lactamase family, endonucleolytically removes 3' trailers from precursor tRNAs, preparing them for CCA addition and aminoacylation. The short form of tRNase Z, tRNase ZS, functions as a homodimer and is found in all prokaryotes and some eukaryotes. The long form, tRNase ZL, related to tRNase ZS through tandem duplication and found only in eukaryotes, possesses ~2,000-fold greater catalytic efficiency than tRNase ZS. tRNase ZL consists of related but diverged amino and carboxy domains connected by a flexible linker (also referred to as a flexible tether) and functions as a monomer. The amino …

Chloride Intracellular Channel Proteins Respond To Heat Stress In Caenorhabditis Elegans, Jun Liang, Yakov Shaulov, Cathy Savage-Dunn, Stéphane Boissinot, Tasmia Hoque

Publications and Research

Chloride intracellular channel proteins (CLICs) are multi-functional proteins that are expressed in various cell types and differ in their subcellular location. Two CLIC homologs, EXL-1 (excretory canal abnormal like-1) and EXC-4 (excretory canal abnormal± 4), are encoded in the Caenorhabditis elegans genome, providing an excellent model to study the functional diversification of CLIC proteins. EXC-4 functions in excretory canal formation during normal animal development. However, to date, the physiological function of EXL-1 remains largely unknown. In this study, we demonstrate that EXL-1 responds specifically to heat stress and translocates from the cytoplasm to the nucleus in intestinal cells and body …

Optimizing A Method For Simultaneous Recovery Of Proteins And Dna From Fingerprints, Steven Kranes

Student Theses

DNA testing on touched objects is a valuable tool in forensic investigations, but DNA is usually present in low amounts, causing poor STR typing results. For touch DNA evidence, there is a clear need for additional individualization, especially for highly probative samples. This could be achieved by testing genetically variable proteins. The goal of this project was to develop a DNA/protein co-extraction method to facilitate DNA and protein testing on the same evidence item. Existing DNA extraction methods were carefully adjusted to allow for downstream mass spectrometry analysis. Initial experiments on saliva and fingerprints placed on glass suggested that trypsin …

The Recycling Gtpase, Rab-10, Regulates Autophagy Flux In Caenorhabditis Elegans, Nicholas J. Palmisano

Dissertations, Theses, and Capstone Projects

Autophagy and endocytosis are two cellular pathways that are vital to cell growth and homeostasis. Autophagy is a dynamic and catabolic process involving the formation of a double-membrane vesicle called the autophagosome, which engulfs long-lived proteins and damaged organelles. Endocytosis involves the uptake of extracellular material into the cell through the formation of intracellular vesicles termed endosomes. Although both endocytosis and autophagy are interconnected processes, the extent to which endocytic proteins and/or compartments contribute to autophagy, and how these endocytic components do so, is still unknown. To improve our understanding of the connections that exist between autophagy and endocytosis, we …

Human Anatomy And Physiology Preparatory Course (1st Edition), Carlos Liachovitzky

Open Educational Resources

The overall purpose of this preparatory course textbook is to help students familiarize with some terms and some basic concepts they will find later in the Human Anatomy and Physiology I course.

The organization and functioning of the human organism generally is discussed in terms of different levels of increasing complexity, from the smallest building blocks to the entire body. This Anatomy and Physiology preparatory course covers the foundations on the chemical level, and a basic introduction to cellular level, organ level, and organ system levels. There is also an introduction to homeostasis at the beginning.

Polymerase Alpha Components Associate With Telomeres To Mediate Overhang Processing, Raffaella Diotti

Dissertations, Theses, and Capstone Projects

Telomeres consist of TTAGGG repeats, which end with a 3' G-overhang and are bound by a six-protein complex, known as Shelterin. In humans, telomeres shorten at each cell division, unless telomerase is expressed and able to add telomeric repeats to the 3' G-overhang. However, for effective telomere maintenance, the DNA strand complementary to that made by telomerase must be synthesized. In this study, I focused on the Polα/primase complex, in particular the subunits p68 (POLA2, the regulatory subunit) and p180 (Polα, the catalytic subunit), and their potential roles at telomeres. I was able to detect p180, p68 and OBFC1, a …

Lipid Dependence In Ras-Driven Tumors, Darin Salloum

Dissertations, Theses, and Capstone Projects

Over past decade, metabolic alterations in cancer cells have received a substantial amount of interest. It had been established that cancer cells undergo a significant amount of metabolic alterations, and some of these alterations are similar to those in normal highly proliferative cells. However, it is becoming more apparent that many of the metabolic alterations are specific to particular oncogenic signaling pathways. Although altered metabolic machinery makes cancer cells more efficient at promoting growth when nutrients are supplied at the sufficient amounts, the dependency of cancer cells on particular metabolic reprogramming deems cancer cells susceptible to disruptions within metabolic network. …

Metabolic Checkpoints In Cancer Cell Cycle, Mahesh Saqcena

Dissertations, Theses, and Capstone Projects

Growth factors (GFs) as well as nutrient sufficiency regulate cell division in metazoans. The vast majority of mutations that contribute to cancer are in genes that regulate progression through the G1 phase of the cell cycle. A key regulatory site in G1 is the growth factor-dependent Restriction Point (R), where cells get permissive signals to divide. In the absence of GF instructions, cells enter the quiescent G0 state. Despite fundamental differences between GF signaling and nutrient sensing, they both have been confusingly referred to as R and therefore by definition considered to be a singular event in G1. Autonomy from …

Structure-Function Analysis Of Zapc, An Ftsz-Ring Stabilizer, In Escherichia Coli Cytokinesis, Lukasz Tchorzewski

Dissertations and Theses

In Escherichia coli, cell division is defined by the polymerization and constriction of a cytokinetic ring (Z ring) formed by FtsZ, a tubulin-like GTPase, at midcell. Division also involves the formation of a multi-protein complex at midcell known as the divisome. Several divisome proteins promote the assembly/disassembly processes of FtsZ, thereby exercising spatiotemporal control over division. Among FtsZ regulatory proteins are the FtsZ ringassociated proteins (Zap), which either directly or indirectly stabilize the Z-ring by increasing lateral interactions amongst FtsZ protofilaments in the Z-ring. ZapA-D are recruited during early cytokinesis and have overlapping functions in stabilizing FtsZ at midcell, but …

Transformation Of Stimulus Correlations By The Retina, Kristina D. Simmons, Jason Prentice, Gašper Tkačik, Jan Homann, Heather K. Yee, Stephanie E. Palmer, Philip C. Nelson, Vijay Balasubramanian

Publications and Research

Redundancies and correlations in the responses of sensory neurons may seem to waste neural resources, but they can also carry cues about structured stimuli and may help the brain to correct for response errors. To investigate the effect of stimulus structure on redundancy in retina, we measured simultaneous responses from populations of retinal ganglion cells presented with natural and artificial stimuli that varied greatly in correlation structure; these stimuli and recordings are publicly available online. Responding to spatio-temporally structured stimuli such as natural movies, pairs of ganglion cells were modestly more correlated than in response to white noise checkerboards, but …

Identification Of An Archaeal Presenilin-Like Intramembrane Protease, Celia Torres-Arancivia, Carolyn M. Ross, Jose Chavez, Zahra Assur, Georgia Dolios, Filippo Mancia, Iban Ubarretxena-Belandia

Publications and Research

Background: The GXGD-type diaspartyl intramembrane protease, presenilin, constitutes the catalytic core of the c-secretase multi-protein complex responsible for activating critical signaling cascades during development and for the production of b-amyloid peptides (Ab) implicated in Alzheimer’s disease. The only other known GXGD-type diaspartyl intramembrane proteases are the eukaryotic signal peptide peptidases (SPPs). The presence of presenilin-like enzymes outside eukaryots has not been demonstrated. Here we report the existence of presenilin-like GXGD-type diaspartyl intramembrane proteases in archaea.

Methodology and Principal Findings: We have employed in vitro activity assays to show that MCMJR1, a polytopic membrane protein from the archaeon Methanoculleus marisnigri JR1, …