Cell and Developmental Biology Commons^™

Architects Of Mrna Fate: Molecular And Cellular Control Of P-Body Organization In The Drosophilia Melanogaster Female Germline, Samantha Milano

Dissertations, Theses, and Capstone Projects

Processing bodies (P-bodies) are cytoplasmic ribonucleoprotein condensates that regulate mRNA storage, translational repression, and decay. While the biochemical principles governing condensate assembly have been extensively studied in vitro, how P-body organization is established and dynamically regulated in vivo to control specific mRNA populations remains poorly understood. This dissertation investigated the molecular and cellular mechanisms that govern P-body architecture and function in the Drosophila melanogaster female germline. First, I identified the conserved LSm protein Trailer Hitch (Tral) as a central organizer of P-body architecture. Using quantitative confocal and super-resolution microscopy combined with chemical perturbations, I showed that Tral coordinates the …

Profiling Nucleolin Phosphorylation During Dna Damage Response And Cell Cycle Arrest, Hanjun Jeon

Dissertations, Theses, and Capstone Projects

This dissertation examines site-specific and global phosphorylation dynamics of nucleolin (NCL) in response to DNA damage and cell-cycle perturbations. By combining phospho-specific immunoblotting with Phos-tag SDS-PAGE analysis, distinct phosphorylation patterns were identified across experimental conditions. The results define reproducible, condition-dependent phosphorylation states of NCL and provide a framework for studying its regulation under cellular stress.

Characterization And Advancement Of Molluscan Venom Gland Cell Model Systems, James V. Parziale

Dissertations, Theses, and Capstone Projects

Venomous mollusks, including cone snails and coleoid cephalopods, produce rich repertoires of bioactive peptides with profound effects on cellular physiology, yet there are few tractable experimental systems that exist to study their development, maintenance, and venom secretion. Although therapeutics such as the cone snail peptide Ziconotide demonstrate the biomedical potential of molluscan venoms, progress in understanding how venom glands form, function, and evolve has been hindered by the lack of reliable husbandry and the complete absence of in vitro cell models. Modern comparative genomics has revealed widespread convergent evolution across venomous lineages, but molluscan datasets remain underrepresented, limiting insights into …

Potential Role Of A Ruthenium-Based Compound Ru-Im In The Treatment Of Triple Negative Breast Cancer, Rachele Rameau

Dissertations, Theses, and Capstone Projects

Triple negative breast cancer (TNBC) is an aggressive and heterogeneous molecular subtype of breast cancer that has limited available treatments. The organometallic cationic ruthenium derivative Ru-IM was found to be highly water soluble, was differentially toxic for breast cancer cells and tumors, and was involved in the pI3K/AKT/mTOR pathway. However, a full understanding of genetic and epigenetic factors that can be part of regulatory mechanisms of Ru-IM is yet to be determined. Epigenetic assays including DNA methylation, histone acetylation and histone deacetylation were performed with the half inhibitory concentration (IC50) values of Ru-IM. Bisulfite sequencing of untreated and treated MDA-MB-231 …

Retinal Precursor Cell Enriched Multiomic And Pseudo-Time Analysis Of Developing And Reprogrammed Photoreceptors, Brendon M. Patierno

Dissertations, Theses, and Capstone Projects

The vertebrate retina is a complex tissue made up of seven major cell subtypes which during development must differentiate and localize into a highly organized structure. These neuronal cells do not regenerate if damaged or diseased, and the progressive deterioration of cone photoreceptor cells is the leading cause of age related blindness. Currently there are no cures for this disease, but one promising therapeutic avenue is cell transplantation research. If we can further elucidate the gene regulatory networks that define cone cell development, this knowledge could be applied to the generation of healthy cone cells in clinically relevant models.

The …

The Sonic Hedgehog Effector Smoothened Modulates Cholinergic Interneuron Activity, Physiology, And Striatum-Dependent Behaviors, Santiago Uribe-Cano

Dissertations, Theses, and Capstone Projects

The striatum is a central node in action selection and associative learning, integrating cortical, thalamic, and neuromodulatory input. Among its principal modulators, dopamine (DA) and acetylcholine (ACh) are known for their temporally coordinated yet mechanistically distinct influences on striatal output. However, the upstream signals that regulate their dynamic interplay, particularly within cholinergic interneurons (CINs)—the primary source of striatal ACh—remain incompletely characterized. This dissertation investigates the role of Smoothened (Smo), a G protein-coupled receptor (GPCR) effector of Sonic Hedgehog (Shh) signaling, in modulating ACh signaling dynamics in the striatum.

Building on evidence that midbrain DA neurons co-release Shh and that CINs …

Mechanistic Insights Into The Neuroprotective Effects Of The Antidepressant Agomelatine In Alzheimer's Disease, Grace Terry

Dissertations, Theses, and Capstone Projects

Alzheimer’s Disease (AD) is a complex neurodegenerative disease that has limited treatment options and no cure. AD is characterized by robust pathology including extracellular amyloid beta plaques, intracellular neurofibrillary tangles, neuronal and synaptic loss, neuroinflammation, and brain atrophy. AD presents with cognitive decline and memory loss but only years after neuropathology has started to accumulate. This robust pathology has made AD difficult to treat and highlights the need for therapeutics that modulate multiple pathways. Agomelatine (AGO) was selected by a high-throughput machine learning drug repurposing algorithm by our collaborator Dr. Lie Xie (Hunter College Dept. of Comp. Sci.) as having …

Bmp Signaling Co-Regulation Of Immune Response And Lipid Metabolism, Katerina K. Yamamoto

Dissertations, Theses, and Capstone Projects

The Bone Morphogenetic Proteins (BMPs) are secreted peptide ligands of the Transforming Growth Factor beta (TGF-β) family, initially identified for their roles in development and differentiation across animal species. They are now increasingly recognized for their roles in physiology and infectious disease. In the nematode Caenorhabditis elegans, the BMP ligand DBL-1 controls fat metabolism and immune response, in addition to its roles in body size regulation and development. DBL-1 regulates classical aspects of innate immunity, including the induction of anti-microbial peptides. We theorized that BMP-dependent regulation of fat metabolism could also promote resilience against microbial pathogens. We found that …

Investigating The Role Of Early Growth Response 1 (Egr1) Gene In Riluzole-Induced Apoptosis In Osteosarcoma, Syeda Maryam Azeem

Dissertations, Theses, and Capstone Projects

Osteosarcoma is a rare but aggressive bone malignancy most commonly affecting adolescents and young adults (AYA). With 5-year survival rate stagnating over the last four decades despite the advancements in multi-modal therapy, drug repurposing offers a rapid path to new osteosarcoma treatments. Recent studies suggest that Riluzole, a drug approved for amyotrophic lateral sclerosis (ALS), may be repurposed for osteosarcoma treatment due to its ability to slow tumor progression and induce apoptosis. Previously, we have shown that Riluzole increases reactive oxygen species (ROS), activating c-Abl, which phosphorylates YAP in the nucleus. YAP then forms a complex with p73 to enhance …

Elucidating The Roles Of Eukaryotic Initiation Factors Involved In Dap5 Mediated Translation, Jacob Nk Quartey

Dissertations, Theses, and Capstone Projects

Translation initiation in eukaryotes is a highly regulated process essential for accurate protein synthesis. It is a dynamic process that involves a complex interplay between messenger RNAs (mRNAs), ribosomal subunits, and a host of initiation factors, ensuring precise start codon selection and the subsequent assembly of the translation machinery. This process has well been known to be mediated by the eukaryotic Initiation Factor (eIF4F), which consists of the cap binding protein eIF4E, the scaffolding protein eIF4GI, and the helicase factor eIF4A.The recognition and binding of eIF4E to the m⁷G cap structure of the mRNA is essential for the …

Understanding How Genetic Mutations Induce Oligodendrocyte Progenitors To Become Cancer Cells, Dennis Huang

Dissertations, Theses, and Capstone Projects

Gliomas are the most devastating adult brain tumors characterized by poor survival rate and limited options for treatment. Previous studies have shown that they are very heterogeneous and can be further sub-classified based on their transcriptional signature and the presence of specific mutations. One such subtype, is the “proneural glioma”, which is characterized by the enrichment in oligodendrocyte progenitor cell (OPC) transcripts and mutations in genes encoding for the tumor suppressor P53 (Trp53) and for Platelet Derived Grow Factor (PDGF) signaling. Since OPCs are the most abundant proliferative population in the adult brain, in this …

The Role Of Secondary And Tertiary Structure In The Cap-Independent Translation Of Fgf-9 And Hif-1-Alpha, Amanda Michelle Whittaker

Dissertations, Theses, and Capstone Projects

Under normoxic conditions, eukaryotes initiate translation of RNA through eIF4E recognition of the 5’ cap. However, under cellular stress, eukaryotic translation must be initiated through a 4E-independent, or “cap-independent” mechanism, involving eukaryotic initiation factor 4G (eIF4G) binding directly to the 5’ untranslated regions (5’ UTR) of the RNA. eIF4G binding then recruits the ribosome to the transcript. While this mechanism is useful for translation of apoptotic transcripts and transcripts involved in cell survival, cap-independent translation is also utilized by oncogenic RNA for tumorigenesis. Previous work by our lab and others has categorized this recruitment and initiation mechanism as either internal-ribosome-entry-site …

Autophagy And Meiotic Fidelity In C. Elegans, Kaitlin E. Kosinski

Dissertations, Theses, and Capstone Projects

Autophagy is an evolutionarily conserved multi-step recycling process in which cellular material is enclosed in the double membrane-bound autophagosome, which fuses with the lysosome to degrade its contents. Autophagy is essential for development and cellular adaptation to environmental or intracellular stress and is an important regulator of germline stem cell homeostasis in the model nematode C. elegans. We sought to determine if autophagy is important for genome stability during meiosis and found that the core adult C. elegans autophagy genes bec-1, atg-7, unc-51, and atg-18 were all required for proper meiotic development of oocytes. Loss of these …

High Mdmx (Mdm4) In Mutant P53 Expressing Breast Cancer Cells Activates The Cxcl12-Cxcr4 Metastasis Signaling Axis, Rusia H. Lee

Dissertations, Theses, and Capstone Projects

The metastasis-promoting G-protein coupled receptor (GPCR) CXCR4 is activated by the cytokine CXCL12 (also known as SDF-1) to promote metastasis through CXCR4 upregulation. High CXCR4-expressing cancer cells utilize CXCL12, the exclusive endogenous ligand of CXCR4, to intravasate into the blood as circulating tumor cells (CTCs) which then extravasate to distant metastatic sites. We previously determined the oncogenes, Mouse Double Minute 2 and 4 (MDM2 and MDM4, also known as MDMX), drive TNBC metastasis and positively correlate with high expression of CXCR4. Interestingly, this upregulation of CXCR4 was only observed in primary tumor cells grown in the tumor microenvironment …

Mechanistic And Engineering Studies Of Lov Photoreceptors In Yeast, Matthew M. Cleere

Dissertations, Theses, and Capstone Projects

A variety of cellular biosensors have evolved which can translate electromagnetic radiation from the environment into biological functions. Light-Oxygen-Voltage (LOV) domains in particular, are a group of photoreceptors that respond to blue wavelengths of light and can become a cellular photoswitch by converting this stimulus through their attached effector domains. For instance, the Helix-Turn-Helix (HTH) DNA-binding activity of the bacterial transcription factor EL222 and the Regulator of G-protein Signaling (RGS) in the fungal membrane associating protein BcLOV4 are both induced by blue-light sensing LOV domains. While previous work has provided the field with a structural characterization of LOV proteins in …

Targeting Strategies To Optimize The Therapeutic Potential Of Gold Compounds Against Her2-Positive Breast Cancers, Afruja Ahad

Dissertations, Theses, and Capstone Projects

The overexpression of HER2 accounts for 20-30% of breast cancer tumors and not only serves as a marker for poor predictive clinical outcomes but also as a target for treatment. Antibody-drug conjugates (ADCs) combine the selectivity of monoclonal antibodies (mAbs) with the efficacy of chemotherapeutic drugs to provide targeted treatment without toxicity to normal tissue. Most of the ADCs currently in the clinic for cancer chemotherapy are based on complex organic molecules. In contrast, the conjugation of metallodrugs to mAbs has been overlooked when there is enormous potential in this area with the resurgence of metal-based drugs as prospective cancer …

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 …

Protein-Protein Interactions In Cell Cycle Proteins: An In Silico Investigation Of Two Important Players, Andriele Eichner

Dissertations, Theses, and Capstone Projects

The examination of the cell cycle carries significant implications for the biology, health, and overall existence of all living things. These implications span from the development and growth of these organisms to the aging process and cancer, as well as the potential of stem cell therapies to repair diseases and injuries. Numerous proteins of the cell cycle are essential for cellular division and proliferation and are widely conserved over the course of evolution. In this work, we aimed to investigate the molecular processes of protein-protein interactions in cell cycle proteins, centering on two key players: Cdc6 in budding yeast and …

Metabolic Control Of Proliferation And Differentiation In Oligodendrocytes, Sami Sauma

Dissertations, Theses, and Capstone Projects

Oligodendrocytes (OLs) are specialized cells whose membrane extension, called myelin, wraps the axons providing insulation, trophic and metabolic support, and is essential for proper functioning of the central nervous system. Inappropriate myelin formation, damage or dysfunction of oligodendrocytes has been identified in several neurological disorders and often precedes the loss of neuronal cells. OLs derive from proliferating oligodendrocyte progenitor cells (OPCs), which exit from the cell cycle and undergo a series of transcriptional and epigenetic events, including histone post-translational modifications, resulting in morphological and functional changes. Our lab previously identified elevated levels of histone acetylation in proliferating OPCs during the …

Pre-Clinical Evaluation Of A Potential Ruthenium-Based Chemotherapeutic Agent For The Treatment Of Triple Negative Breast Cancer, Nazia Nayeem

Dissertations, Theses, and Capstone Projects

Triple negative breast cancer (TNBC) is an aggressive subtype of breast cancer that represents roughly 15% of all diagnosed breast cancers. TNBC is defined by the absence of expression of progesterone, estrogen, and human epidermal growth factor 2 receptors, and has a higher incidence rate in pre-menopausal women and women of African and of Hispanic ancestry. Due to the inability to target a receptor, treatment is limited to nonspecific chemotherapy or immunotherapy. Only one FDA approved therapy is available specifically to treat TNBC, which is antibody drug conjugate Sacitzumab-govitecan, given to patients who have already gone through two rounds of …

Changes In The Epigenetic Landscape Of Oligodendrocyte Progenitor Cells With Time, David K. Dansu

Dissertations, Theses, and Capstone Projects

Most neonatal oligodendrocyte progenitors (nOPCs) give rise to myelinating oligodendrocytes during development, while a proportion are retained as proliferative undifferentiated cells in the adult brain (aOPCs). Previous studies have reported distinct properties for those two populations but the molecular mechanisms underlying these intrinsic differences are not well understood. Using RNA-sequencing and unbiased histone proteomics analysis, we identify transcripts and histone marks that are higher in aOPCs than nOPCs. The genome-wide ChIP-sequencing analysis of chromatin from aOPCs compared to nOPCs detects greater occupancy of the H4K8ac mark at loci corresponding to the higher transcript levels of oligodendrocyte-specific transcription factors and lipid …

Multi-Target Ligand-Guided Selection (Ligs) Against B-Cell Specific Antigens Expressed In A Single Lymphoma Cell Population, Nicole B. Williams

Dissertations, Theses, and Capstone Projects

Nucleic acid ligands called aptamers are single-stranded DNA or RNA molecules which fold into functional three-dimensional structures to facilitate their target binding with high affinity and specificity. The method used to generate aptamers is an in vitro process called Systematic Evolution of Ligands by Exponential enrichment (SELEX). A variant of SELEX, cell-SELEX has been used to select aptamers against cell-surface proteins in their native state. We recently introduced a novel method called Ligand-Guided Selection (LIGS) to identify aptamers against cell-surface markers. Herein, we expanded LIGS method into a multiplexing platform to partition multiple aptamers against B-cell-specific antigens, CD19 and CD20, …

Isolation And Characterization Of Fluorescent Proteins And Small Molecules From Marine Vertebrates, Sara Rose Krivoshik

Dissertations, Theses, and Capstone Projects

Fluorescence is a phenomenon in which a wavelength of light excites a fluorophore and then emits light at a higher, longer wavelength. This occurs throughout the biological world, in both the terrestrial and marine realms. Encompassing a diverse set of mechanisms from small molecules to large protein complexes; fluorescence has been used as a biological tool with a wide range of applications to study molecular and cellular biology for decades. This dissertation looks to identify and characterize novel fluorescent proteins and small molecules to allow for more efficient translation in developing new biotechnologies. Using a combination of RNA-Seq, Mass-Spec, protein …

Determining The Roles Of The Oligomerization And C-Terminal Domains In Mutant P53 Gain-Of-Function Activities, George K. Annor

Dissertations, Theses, and Capstone Projects

The tumor suppressor p53 (TP53) gene is often mutated in cancer, with missense mutations found in the central DNA binding domain, and less often in the oligomerization domain (OD) and C-terminal domain (CTD). The OD and CTD have been found to be critical for the tumor suppressor functionality of wild-type p53 (wtp53). Specific missense mutations in the DNA binding domain have been found to confer new gain-of-function (GOF) activities. Mutations that destabilize tetramer formation, or deletion of key lysine residues within the CTD, downregulate the ability of wtp53 to transactivate (increase the rate of transcription of) its target …

Gamma Protocadherin Synaptic Localization And Intracellular Trafficking Is Consistent With Distinct Adhesive And Anti-Adhesive Roles In Development, Nicole Lamassa

Dissertations, Theses, and Capstone Projects

Clustered protocadherins (Pcdhs) constitute a family of cell adhesion molecules with approximately 60 Pcdh genes clustered in a 1 MB locus on chromosome 5q31 in humans. The Pcdh gene cluster is subdivided into α, β, and γ subclusters which encode related proteins. Individual neurons activate different subsets of Pcdh-α, Pcdh-β and Pcdh-γ genes by epigenetic mechanisms to generate distinct Pcdh adhesive units expressed by each neuron. This is thought to serve as a “surface barcode” for single-cell identity and synaptic recognition in the nervous system. The actual role for Pcdhs in neural development is still relatively unknown and different roles …

Clustered Protocadherins Ubiquitination And Phosphorylation Regulates Surface Expression, Albert Ptashnik

Dissertations, Theses, and Capstone Projects

Clustered protocadherins (Pcdhs) are a family of 60 adhesion-like molecules forming a neural barcode. In vertebrate neurons, 60 Pcdhs are coded by a large gene cluster. Numerous axons in the cluster are coding for the different extracellular, transmembrane, variable portion of the cytoplasmic and constant cytoplasmic domains where their expression is controlled epigenetically. These proteins mediate interactions between axons, dendrites, and glial cells during neural development. Yet, Pcdhs are not strictly adhesion molecules. In the amacrine cells of the retina, Pcdhs promote avoidance of the same cell dendrites, where in the cortex Pcdhs promote interactions between dendrites and astrocytes. In …

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 …

Cdc6 Is Sequentially Regulated By Pp2a-Cdc55, Cdc14, And Sic1 For Origin Licensing In S. Cerevisiae, Jasmin Philip

Dissertations, Theses, and Capstone Projects

Control of DNA replication is critical for progression of the cell cycle and genomic stability. Cyclin-dependent kinases (CDKs) coordinate numerous phosphorylation events to accomplish two biological tasks for all living organisms: DNA replication and cell division. One CDK, Cyclin-Cdc28, is responsible for cell cycle progression in budding yeast. DNA replication requires a stepwise assembly of the pre-replicative complex on DNA, including Orc1-6, Cdc6, Cdt1 and Mcm2-7, during M-G1 phase. Cdc6 contains eight Cdc28 consensus sites, SP or TP motifs. Clb5-Cdc28 phosphorylates Cdc6-T7 to recruit Cks1, the Cdc28 phospho-adaptor, for subsequent multisite phosphorylation during S phase. There are two phospho-degrons at …

Study Of The Gain-Of-Function Mutant P53 And Parp1 In Triple-Negative Breast Cancer, Devon Lundine

Dissertations, Theses, and Capstone Projects

Cancer cells often lose expression of the p53 protein or express mutant forms of p53. Some of these mutant p53 proteins, called gain-of-function mutant p53, have gained oncogenic functions. Previously, our group observed mutant p53 R273H interacts with replicating DNA and upregulates the chromatin localization of several DNA replication factors including PCNA, MCM2-7, and PARP1 (termed the mtp53-PARP-MCM axis). In this thesis, we explore the contribution of mutant p53 and PARP1 in castration-resistant prostate cancer (mutant p53 P223L and V274F) and triple-negative breast cancer (mutant p53 R273H). In the castration-resistant prostate cancer cell line DU145, we examine two mutant p53 …

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 …