Biochemistry, Biophysics, and Structural Biology Commons^™

Evaluating The Interaction Between The Human Melanocortin-2 Receptor And The Accessory Protein, Mrap1: Chimeric Receptor And Alanine Substitution Studies On Transmembrane Domain 4, Extracellular Loop 2, And Transmembrane Domain 5, Perry Victoria Davis

Electronic Theses and Dissertations

The melanocortin-2 receptor (MC2R) is the most complex due to its trafficking and ligand selectivity requirements for proper activation. The MC2R requires the melanocortin receptor accessory protein-1 (MRAP1) for proper trafficking and activation of the receptor by the melanocortin hormone, ACTH. MRAP1 is a single transmembrane-spanning domain protein that creates a homodimer with another MRAP1 protein. Furthermore, MRAP2 creates a heterodimer with the MC2R. Previous studies have shown that the MRAP1 protein contains an activation motif required for activation of MC2R and this activation motif located on the extracellular space side of the plasma membrane of the cell. The objective …

Controlling Platelet Secretion To Modulate Hemostasis And Thrombosis, Smita Joshi

Theses and Dissertations--Molecular and Cellular Biochemistry

Upon vascular injury, activated blood platelets fuse their granules to the plasma membrane and release cargo to regulate the vascular microenvironment, a dynamic process central to platelet function in many critical processes including hemostasis, thrombosis, immunity, wound healing, angiogenesis etc. This granule- plasma membrane fusion is mediated by a family of membrane proteins- Soluble N-ethyl maleimide Attachment Receptor Proteins(SNAREs). SNAREs that reside on vesicle (v-SNAREs) /Vesicle-Associated Membrane Proteins(VAMPs) interact with target/t-SNAREs forming a trans-bilayer complex that facilitates granule fusion. Though many components of exocytic machinery are identified, it is still not clear how it could be manipulated to prevent …

Functional Characterization Of Scaffold Protein Shoc2, Hyein Jang

Theses and Dissertations--Molecular and Cellular Biochemistry

Signaling scaffolds are critical for the correct spatial organization of enzymes within the ERK1/2 signaling pathway and proper transmission of intracellular information. However, mechanisms that control molecular dynamics within scaffolding complexes, as well as biological activities regulated by the specific assemblies, remain unclear.

The scaffold protein Shoc2 is critical for transmission of the ERK1/2 pathway signals. Shoc2 accelerates ERK1/2 signaling by integrating Ras and RAF-1 enzymes into a multi-protein complex. Germ-line mutations in shoc2 cause Noonan-like RASopathy, a disorder with a wide spectrum of developmental deficiencies. However, the physiological role of Shoc2, the nature of ERK1/2 signals transduced through this …

Effectiveness And Mechanism Of Action Of Modified Porphyrins For Photodynamic Therapy Of Triple Negative Breast Cancer Cells, Alex Abbott

Honors Theses

Triple negative breast cancer is an aggressive family of cancers that are extremely difficult to treat. Therefore, the prognosis for most patients with TNBC is poor. The goal of this research is to determine if photodynamic therapy could be a possible option for TNBC in the future using MDA-MB231 cells. MDA-MB231 cells were originally isolated from a patient with triple negative breast cancer and have been used for many studies, so they would work well for this study. Photodynamic therapy uses compounds called photosensitizing agents which are taken up by all tissues in the body and then activated by light. …

Optimisation Of Ion Exchange Chromatography Purification Protocols For A Staphylococcal Peptidoglycan Degrading Hydrolase Enzyme, Fiona Maher

Theses

Bacteriophage (phage) are the most abundant biological entities on earth and were first discovered by d’Herelle in 1917. They are found wherever their hosts live and, like all viruses they do not have the ability to make their own protein. Therefore, in order to reproduce, phage must invade and infect bacterial cells. This project focused on the optimisation of Ion Exchange Chromatography purification protocols for a staphylococcal peptidoglycan degrading hydrolase enzyme (CHAPk). The project objective was to obtain the greatest yield of enzyme from the growth of the E.coU XL 1-Blue expression system into which the vector pQE60 was previously …

Targeting The Cellular Redox Environment: A Novel Approach For The Treatment Of Hematopoietic Neoplasms, Dustin W. Carroll

Theses and Dissertations--Toxicology and Cancer Biology

Hematopoietic stem cells (HSCs) that function to maintain the hematopoietic compartment through self-renewal and differentiation capacities, as well as their downstream progeny, are susceptible to transformation resulting in the generation of the leukemic stem cell (LSC). Chief in the factors that control HSC regulation and protection of the HSC compartment is the cellular redox environment. Deregulation of the Hematopoietic Stem/Progenitor Cell (HSPC) redox environment results in loss of HSPC function and exhaustion. The characteristic developments of HSPC exhaustion via exposure to redox stress closely mirror phenotypic traits of hematopoietic malignancies, presenting the HSPC/LSC redox environment as a potential therapeutic target. …

Carbohydrate-Based Inducers Of Cellular Stress For Targeting Cancer Cell Metabolism, Fidelis Ndombera

Wayne State University Dissertations

ABSTRACT

CARBOHYDRATE-BASED INDUCERS OF CELLULAR STRESS FOR TARGETING CANCER CELL METABOLISM

by

FIDELIS TOLOYI NDOMBERA

May 2018

Advisor: Dr. Young-Hoon Ahn

Major: Chemistry (Biochemistry)

Degree: Doctor of Philosophy

Metabolic reprogramming and redox control of cancer cells is vital for their proliferation, but also provides selective strategies for treating cancer. Increased generation of reactive oxygen species (ROS) and an intricate control of redox status in cancer cells relative to normal cells provide a basis for designing ROS-inducing anticancer agents. In my work, I designed, synthesized and evaluated carbohydrate-based small molecules for ROS-generation, cytotoxicity and redox signaling and stress response. Our data …

Applications Of Cell-Derived Vesicles: From Single Molecule Studies To Drug Delivery, Faruk H. Moonschi

Theses and Dissertations--Chemistry

Single molecule studies can provide information of biological molecules which otherwise is lost in ensemble studies. A wide variety of fluorescence-based techniques are utilized for single molecule studies. While these tools have been widely applied for imaging soluble proteins, single molecule studies of transmembrane proteins are much more complicated. A primary reason for this is that, unlike membrane proteins, soluble proteins can be easily isolated from the cellular environment. One approach to isolate membrane proteins into single molecule level involves a very low label expression of the protein in cells. However, cells generate background fluorescence leading to a very low …

Determination Of The Sivmac Vif-Human Apobec3b Interaction, Oumar Sanogo

All Graduate Theses, Dissertations, and Other Capstone Projects

The APOBEC3 family of enzymes are DNA cytosine deaminases, some of which restrict replication of HIV-­‐1. This viral restriction is caused by deamination of cytosines to uracils in the viral cDNA, resulting in lethal mutation. HIV-­‐1 counteracts this deamination by producing the protein Vif, which targets the restricting APOBEC3 enzymes for proteosomal degradation. Previous studies have demonstrated that HIV-­‐1 Vif mediates degradation of APOBEC3D (A3D), APOBEC3F (A3F), APOBEC3G (A3G), and APOBEC3H (A3H). Other lentiviruses may also encode a Vif protein, however not all Vif proteins can degrade the same APOBEC3 proteins. For example, SIVmac (simian immunodeficiency virus that infects rhesus …

Retinoic Acid Receptor Isoform-Specific Control Of Mouse Salivary Gland Development And Regeneration, Kara Desantis

Legacy Theses & Dissertations (2009 - 2024)

Controlled expansion and differentiation of progenitor cell populations is essential for organogenesis followed by continued maintenance of the population into and through adulthood. As the K5+ basal cell population is regulated by retinoic acid signaling, we interrogated the contribution of specific RAR isoforms to the regulation of these cells during submandibular salivary gland (SMG) organogenesis and regeneration. Retinoic acid has previously been shown to be involved in the development of the salivary gland, and recently, lack of retinoid signaling has been shown to impact the K5+ population of basal progenitor cells. Since retinoic acid is known to exert stimulatory effects …

Regulated Transcriptional Silencing Promotes Germline Stem Cell Differentiation In Drosophila Melanogaster, Pooja Flora

Legacy Theses & Dissertations (2009 - 2024)

Germ cells are the only cell in an organism that have the capacity to give rise to a new organism and are passed from one generation to the next. Therefore, to maintain this unique ability of totipotency and immortality, germ cells execute specific functions, such as, repression of a somatic program and contour a germ line-specific pre- and post-transcriptional gene regulatory landscape. In many sexually reproducing organisms, germ cells are formed during the earliest stages of embryogenesis and undergoes several stages of development to eventually get encapsulated by the somatic cells of the gonad. Once, in the gonad, the germ …

Chromatin-Signaling Axis Orchestrates The Formation Of Germline Stem Cell Differentiation Niche In Drosophila, Maitreyi Upadhyay

Legacy Theses & Dissertations (2009 - 2024)

Stem cells have the unique capability of self-renewing into stem cells and differentiating into several terminal cell types. Loss of either of these processes can lead to aging, progression towards degenerative diseases and cancers. Insight into how self-renewal and differentiation are regulated will have tremendous therapeutic impact. Drosophila is an excellent model system for stem cell study due to the availability of various mutants, markers and RNAi technology. In order to study stem cell biology, we use female Drosophila gonads, whose stem cell population – the germline stem cells (GSCs) gives rise to gametes.

Evidence For The Involvement Of Runx1 And Runx2 In Maintenance Of The Breast Cancer Stem Cell Phenotype, Mark Fitzgerald

Graduate College Dissertations and Theses

In the United States, metastatic breast cancer kills approximately 40,000 women and 400 men annually, and approximately 200,000 new cases of breast cancer are diagnosed each year. Worldwide, breast cancer is the leading cause of cancer deaths among women. Despite advances in the detection and treatment of metastatic breast cancer, mortality rates from this disease remain high because the fact is that once metastatic, it is virtually incurable. It is widely accepted that a major reason breast cancer continues to exhibit recurrence after remission is that current therapies are insufficient for targeting and eliminating therapy-resistant cancer cells. Emerging research has …

A Proximity-Dependent Biotin Labeling Based Screen For Protein Kinase A Anchoring Proteins Within Focal Adhesion Complexes, Hannah Naughton

Graduate College Dissertations and Theses

Protein kinase A (PKA) regulates a diverse array of cellular activities including metabolism, differentiation, actomyosin contractility, and migration. The multifunctionality of this ubiquitous enzyme is achieved, in part, through subcellular targeting mediated by the A Kinase Anchoring Proteins (AKAP) family of proteins. AKAPs serve as scaffolding proteins that localize PKA to various cellular compartments and bring together specific targets and modulators of PKA activity.

The importance of spatially restricted PKA signaling is particularly apparent in the context of cell motility. It has been observed that both anchoring through AKAPs and the subsequent localized activation of PKA at the leading edge …

Zebrafish Model Of Mll-Rearranged Acute Myeloid Leukemia, Alex J. Belt

Theses and Dissertations

Acute myeloid leukemia (AML) is the second most common type of leukemia and accounts for 80% of adult acute leukemia cases and is characterized by the accumulation of poorly or undifferentiated myeloid blast cells. Standard treatment includes chemotherapy, which if unsuccessful, is followed by more rigorous chemotherapy as well as stem cell transplantation. Considering most patients are over the age of 45, these more rigorous therapies are not always possible, and as such, new therapies must be developed. Furthermore, AML patients harboring a chromosomal rearrangement involving Multiple Lineage Leukemia (MLL) that results in the expression of an MLL fusion protein …

Investigating Phosphorylation Patterns And Their Effect On The Activity Of Transcription Factor Taabf1 In Imbibing Cereal Grains, Grace Uwase

Honors Theses

The wheat transcription factor TaABF1 plays an important role in hormone-mediated regulation of seed dormancy and germination of cereal grains. Evidence shows that TaABF1 activity is regulated by phosphorylation, and previous work in our lab showed that when serine residues in its conserved regions; S36, S37, S113, S115 were altered to phosphomimetic aspartate, the 4xD TaABF1 mutant had increased activity as a transcription factor. However, when only S113 was altered, TaABF1’s activity was greatly reduced. The work presented here explored whether the S36D/S37D/S115D mutant would have stronger activity than the 4xD mutant. Using the particle bombardment technique to introduce the …

Studies Of Norspermidine Uptake In Drosophila Suggest The Existence Of Multiple Polyamine Transport Pathways, Michael Dieffenbach

Honors Undergraduate Theses

Polyamines are a class of essential nutrients involved in many basic cellular processes such as gene expression, cell proliferation, and apoptosis. Without polyamines, cell growth is delayed or halted. Cancerous cells require an abundance of polyamines through a combination of synthesis and transport from the extracellular environment. An FDA-approved drug, D,L-α-difluoromethylornithine (DFMO), blocks polyamine synthesis but is ineffective at inhibiting cell growth due to polyamine transport. Thus, there is a need to develop drugs that inhibit polyamine transport to use in combination with DFMO. Surprisingly, little is known about the polyamine transport system in humans and other eukaryotes. Understanding the …

Altering Oligomerization Of Epha2 Via Mutations In The Intracellular Domain, Ryan W. Lingerak

Williams Honors College, Honors Research Projects

Eph receptor tyrosine kinases (RTKs) are activated by membrane-bound ligands called ephrins. Eph RTKs are divided into two subclasses, each activated by a specific classes of the ligand ephrin. The overexpression of Eph receptors is correlated to cancer cell metastasis in several different types of cancers. Studies with the EphA2 extracellular domain (ECD) and ephrinA1 ligand have shown that upon binding of ephrin to the receptor, EphA2 undergoes increased oligomerization and activation. This indicates that oligomerization is intimately connected to kinase activity. High resolution crystal structures of the EphA2 ECD have revealed some details of these ligand bound oligomers, as …

Evidence For Extra-Gastric Expression Of The Proton Pump H+/K+ -Atpase In The Gills And Kidney Of The Teleost Oreochromis Niloticus, Ebtesam Barnawi

Theses and Dissertations (Comprehensive)

It is well known that stomach acid secretion by oxynticopeptic cells of the gastric mucosa is accomplished by the H⁺/ K⁺-ATPase (HKA), which is comprised of the HKα1 (gene: atp4a) and HKβ (gene: atp4b) subunits. However, the role of the HKA in extra-gastric organs such as the gill and kidney is less clear especially in fishes. This pump may contribute to active ion and/or acid-base regulation either through direct ion transport or through secondary transport proteins against unfavorable concentration gradients via the energy derived from ATP hydrolysis. In the present work I have demonstrated …