Biochemistry Commons^™

Abl1/2 And Ddr1 Cooperate To Stabilize Braf/Craf To Drive Erk1/2 Reactivation And Promote Mek Inhibitor Resistance In Nras-Mutant Melanomas, Anastasia Lyon

Theses and Dissertations--Pharmacology and Nutritional Sciences

This study addresses the escalating incidence of NRAS-mutant melanomas, a type of skin cancer lacking FDA-approved targeted therapies. Despite ongoing research targeting the RAF/MEK/ERK pathway, existing drugs fail to enhance progression-free survival due to acquired resistance. This project identifies a novel role for ABL1/2 and DDR1 kinases in driving drug resistance and proliferation of NRAS-mutant melanoma cells. ABL1/2 and DDR1 cooperate to promote RAF homodimerization and protein stability in order to reactivate MEK/ERK signaling to drive MEK1/2 inhibitor (MEKi) resistance and promote survival of resistant cells. By targeting ABL1/2 and DDR1 with nilotinib, a FDA-approved anti-leukemic inhibitor, we …

The Delineation Of Platelet Pathology In Cardiometabolic Disease, Chi Peng

Theses and Dissertations--Pharmacology and Nutritional Sciences

Obesity is a multifactorial disease with many comorbidities leading to multiorgan dysfunction. Current studies point towards dysregulation of platelet signaling as a driver for increased risk of cardiovascular disease and stroke. The exact mechanisms remain elusive due to the complex interplay of factors involved, warranting the need to further understand how platelets are affected. Our preliminary data evaluating changes in platelet and coagulation parameters from bariatric patients showed that obesity did not affect platelet count or clotting time as demonstrated in INR values. However, female patients had increased bleeding events before surgery that were decreased after surgery. Due to limitations …

Development Of Functional Plasmonic Nanoceria For The Ultrasensitive Detection Of Ebola Glycoprotein, Carissa A. Sutton

Graduate Theses/Dissertations

Infectious diseases have been increasing in both severity and prevalence, leading to increasing economic burdens and health concerns. Ebola hemorrhagic fever is an infectious disease that is both highly communicable and highly fatal. Current detection methods for the virus have high specificity and sensitivity but have long and/or complicated procedures that do not allow for early virus detection in highly affected areas. Compared to the lengthy procedure of reverse transcription-polymerase chain reaction (RT-PCR), real-time RT-PCR is more time-efficient; however, specificity and sensitivity are reduced. Since early detection of the virus is the only way to increase survival rates, sensitive detection …

Synthesis Of Long Oligodeoxynucleotides, Yipeng Yin

Dissertations, Master's Theses and Master's Reports

Synthetic long oligodeoxynucleotides (ODNs) have found wide applications in diverse fields such as chemical biology, synthetic biology, and genes and genomes synthesis. Those applications leading to a significant demand for their production. However, traditional methods for purifying synthetic ODNs present notable drawbacks, particularly their inability to purify long ODNs, rendering long ODN synthesis challenging. To address these issues, chemical synthesis techniques for long ODNs coupled with non-chromatographic purification methods have been developed. This technology makes the purification of long synthetic ODNs feasible and offers a viable pathway for producing genes and genomes with extensive repeats or stable secondary structures, which …

Atg11 And Atg9 Interaction In Selective Autophagy, Chimi Dolker Sherpa

Master's Theses and Doctoral Dissertations

Selective autophagy, induced by cellular stresses, degrades/recycles a specific cargo. Ithelps prevent diseases like Parkinson’s, Huntington's, cancer, and bacterial infections. It involves the formation of an autophagosome, a double-membrane vesicle that takes the cargo to the vacuole/lysosome for degradation. Atg11, the central organizer of selective autophagy, acts as a scaffold protein, interacting with Atg9, Atg1 and other Atg proteins. Our research focuses on finding mutations in Atg11 that specifically disrupt its interaction with Atg9 without affecting its dimerization or interaction with Atg1. We targeted residues 455-535 of Atg11 as a putative Atg9 interaction site, performing mutagenesis on four key residues …

A Phytochemical Analysis Of Secondary Metabolites In Eupatorium Serotinum, Elise Snow

Theses and Dissertations

Phytochemistry, a subset of Natural Products Chemistry, studies chemically derived products from natural substances. Advances in this field have important applications in medicinal research due to the distinctive and unique properties of natural compounds. All metabolites are produced from the metabolic cycle, which is a pathway that provides energy for the organism. These metabolic compounds vary greatly and are classified based on their function within the organism. Primary metabolites are abundant and contribute to organism growth, development, and maintenance of energy. Secondary metabolites are found in lesser quantity and correlate to natural defense mechanisms. For example, salicylic acid is a …

Inflammation And Tumor Progression: The Differential Impact Of Saa In Breast Cancer Models, Daniel Wilhelm Olivier, Carla Eksteen, Manisha Du Plessis, Louis De Jager, Lize Engelbrecht, Nathaniel Wade Mcgregor, Preetha Shridas, Frederick C. De Beer, Willem J. S. De Villiers, Etheresia Pretorius, Anna-Mart Engelbrecht

Saha Cardiovascular Research Center Faculty Publications

Background: Previous research has shown that the Serum Amyloid A (SAA) protein family is intricately involved in inflammatory signaling and various disease pathologies. We have previously demonstrated that SAA is associated with increased colitis disease severity and the promotion of tumorigenesis. However, the specific role of SAA proteins in breast cancer pathology remains unclear. Therefore, we investigated the role of systemic SAA1 and SAA2 (SAA1/2) in a triple-negative breast cancer mouse model.

Methods: Syngeneic breast tumors were established in wild-type mice, and mice lacking the SAA1/2 (SAADKO). Subsequently, tumor volume was monitored, species survival determined, the inflammatory profiles of mice …

N(Alpha)-Acetyltransferase 40-Mediated Histone Acetylation Plays An Important Role In Ecdysone Regulation Of Metamorphosis In The Red Flour Beetle, Tribolium Castaneum, Sharath Chandra Gaddelapati, Smitha George, Anilkumar Moola, Karthi Sengodan, Subba Reddy Palli

Entomology Faculty Publications

Histone acetylation, a crucial epigenetic modification, is governed by histone acetyltransferases (HATs), that regulate many biological processes. Functions of HATs in insects are not well understood. We identified 27 HATs and determined their functions using RNA interference (RNAi) in the model insect, Tribolium castaneum. Among HATs studied, N-alpha-acetyltransferase 40 (NAA40) knockdown caused a severe phenotype of arrested larval development. The steroid hormone, ecdysone induced NAA40 expression through its receptor, EcR (ecdysone receptor). Interestingly, ecdysone-induced NAA40 regulates EcR expression. NAA40 acetylates histone H4 protein, associated with the promoters of ecdysone response genes: EcR, E74, E75, and HR3, and causes an increase …

The Mechanoreceptor Piezo Is Required For Spermatogenesis In Bombyx Mori, Zhongjie Zhang, Xiaojing Liu, Bo Hu, Kai Chen, Ye Yu, Chenxin Sun, Dalin Zhu, Hua Bai, Subba Reddy Palli, Anjiang Tan

Entomology Faculty Publications

Background The animal sperm shows high diversity in morphology, components, and motility. In the lepidopteran model insect, the silkworm Bombyx mori, two types of sperm, including nucleate fertile eupyrene sperm and anucleate unfertile apyrene sperm, are generated. Apyrene sperm assists fertilization by facilitating the migration of eupyrene spermatozoa from the bursa copulatrix to the spermatheca. During spermatogenesis, eupyrene sperm bundles extrude the cytoplasm by peristaltic squeezing, while the nuclei of the apyrene sperm bundles are discarded with the same process, forming matured sperm.

Results In this study, we describe that a mechanoreceptor BmPiezo, the sole Piezo ortholog in B. mori, …

Investigating A Potential Protein-Protein Interaction Between Transcription Factor Pax6 And Ribosomal Protein S20 (Rps20), Modupe Oladayo

All Master's Theses

The neocortex is the largest region of mammalian brains and is responsible for the complex cognitive abilities and behaviors of mammals. The neocortex of mature mammals is divided into concise areas, which process sensory information from ears, eyes, and touch receptors, and regulate conscious movement of muscles. The combined graded expressions of several transcription factors over the embryonic neocortical ventricular zone regulates the sizes of these functional areas in the adult neocortex. Although progress has been made in understanding how transcription factors affect neocortical patterning, additional research is required to fully understand the underlying molecular mechanism(s), which will contribute to …

Drosophila Parasitoids Go To Space: Unexpected Effects Of Spaceflight On Hosts And Their Parasitoids, Jennifer Chou, Johnny R. Ramroop, Amanda M. Saravia-Butler, Brian Wey, Matthew P. Lera, Medaya L. Torres, Mary Ellen Heavner, Janani Iyer, Siddhita D. Mhatre, Sharmila Bhattacharya, Shubha Govind

Publications and Research

While fruit flies (Drosophila melanogaster) and humans exhibit immune system dysfunction in space, studies examining their immune systems’ interactions with natural parasites in space are lacking. Drosophila parasitoid wasps modify blood cell function to suppress host immunity. In this study, naive and parasitized ground and space flies from a tumor-free control and a blood tumor-bearing mutant strain were examined. Inflammation-related genes were activated in space in both fly strains. Whereas control flies did not develop tumors, tumor burden increased in the space-returned tumor-bearing mutants. Surprisingly, control flies were more sensitive to spaceflight than mutant flies; many of their …

Impact Of Hdac Inhibitors On The Efficiency Of Cardiomyocyte Differentiation, Lauren Mary Sargent

Honors Theses and Capstones

Heart disease and injury is the leading cause of death worldwide, with much of its severity caused by the low regenerative capacity of cardiomyocytes (CMs). One of the strategies to counteract the poor regeneration of CMs is the production of CMs via differentiating stem cells. However, the low efficiency of obtaining CMs from stem cells is an issue because there are numerous inconsistencies in the process. Histone deacetylase (HDAC) inhibitors have been researched as ways to increase efficiency of CM differentiation by increasing histone acetylation, and thereby allowing differentiation to occur more efficiently. In this study, the HDAC inhibitor, trichostatin …

Immune Signaling And Pathogenesis Of Enterocytozoon Hepatopenaei Infection In Pacific White Shrimp Litopenaeus Vannamei, Nutthapon Sangklai

Chulalongkorn University Theses and Dissertations (Chula ETD)

Enterocytozoon hepatopenaei (EHP) is an intracellular microsporidian parasite causing hepatopancreatic microsporidiosis (HPM), a disease that impairs the digestion and nutrients absorption of shrimp and leads to growth retardation and size variation. Our studies aim to comprehensively investigate the host’s immune responses to the EHP infection and the pathogenesis of the parasite. It was found that genes in Toll and JAK/STAT pathways, as well as antimicrobial peptides, were highly upregulated upon the EHP infection. Importantly, suppression of the JAK/STAT pathways resulted in a significant reduction of the c-type lysozyme (LvLyz-c) expression and the elevation of EHP copy numbers. These indicate a …

Whole Genome Crispr-Cas9 Screens Identify Genes Contributing To Viral Entry And Phagocytosis, Md Saddam Hossain

Electronic Theses and Dissertations

CRISPR/Cas9 is a revolutionary technique for genome editing where Cas9 nucleases can be targeted to specific genomic sites by single-guide RNAs (sgRNAs) containing roughly 20-nucleotide sequences that are complementary to the target region. Double strand breaks created by Cas9 are repaired through non-homologous end-joining (NHEJ) in most cells, resulting in insertions and deletions leading to frame shift mutations in coding regions. Thus, the CRISPR-Cas9 system can be exploited for systematic evaluation of gene function relationships by whole genome screening. We also developed a CRISPR whole‐genome screen and counter‐screen strategy based on a pseudoviral platform that allowed identification of genes specific …

Evaluating The Efficacy Of The Archaeal Proteasome To Alleviate Protein-Misfolding Retinopathy, Celine Brooks

Graduate Theses, Dissertations, and Problem Reports (ETD)

Nearly all neurodegenerative diseases (NDs) and some eye diseases are characterized by the presence of misfolded and aggregated proteins. The ubiquitin proteasome system (UPS) is responsible for degrading the majority of proteins including misfolded and aggregated proteins. However, in NDs the performance of the UPS is impaired, and this impairment partially comes from these protein aggregates inhibiting the proteasome. This inhibition leads to an accumulation of protein aggregates, more proteasomal inhibition, and fewer chaperones for newly synthesized proteins, triggering a collapse in proteostasis, which is thought to contribute to the pathogenesis of NDs. Consequently, stimulating proteasome function is being investigated …

The Function Of Protein Glutamylation In Vision, Rawaa Aljammal

Graduate Theses, Dissertations, and Problem Reports (ETD)

Posttranslational glutamylation of protein has emerged as a novel candidate for cellular integrity. In a dynamic process, Tubulin Tyrosine Ligase Like proteins (TTLLs) introduce glutamate groups to their substrates, while Cytosolic Carboxypeptidases members (CCP1-CCP6) remove these glutamate groups. The outcome of this interplay is a wide range of substrates; each is glutamylated to a level crucial for its function.

Protein glutamylation is particularly abundant in neurons and in the axoneme of cilia and flagella. This distribution, along with the correlation between imbalanced glutamylation levels and compromised cellular functions, underscores the significance of protein glutamylation in maintaining cellular viability. However, the …

Structural And Functional Consequences Of Pde6 Prenylation In Rod And Cone Photoreceptors, Faezeh Moakedi

Graduate Theses, Dissertations, and Problem Reports (ETD)

Phosphodiesterase-6 (PDE6) serves as a pivotal component in the phototransduction pathways of both cone and rod photoreceptors. In cones, PDE6 consists of tetrameric subunits: inhibitory (γ') and catalytic (α'). The catalytic subunit, PDE6α', contains a C-terminal prenylation motif. Deletion of this motif is associated with achromatopsia (ACHM), a form of color blindness. The mechanisms underlying the disease and the roles of PDE6 lipidation in vision remain elusive. Meanwhile, rod PDE6 is composed of α and β catalytic subunits and γ inhibitory subunits, with alterations in the C-terminal "prenylation motif" of PDE6β linked to retinitis pigmentosa (RP) pathology. In this comprehensive …

The Role Of Sugars In Aggregation Of The Protein Kassinin, Lillie G. Waldron

Student Summer Scholars Manuscripts

The aggregation of proteins to form amyloids is implicated in several diseases such as Alzheimer’s Disease, Parkinson’s Disease, and many others. This aggregation has several stages, progressing from isolated protein molecules (monomers) to small aggregates (oligomers), which are toxic to cells, and finally to large, string-like mature aggregates. Despite this association with disease, functional amyloids, which have normal biological functions, also result from protein aggregation. Kassinin, an amphibian peptide involved in nerve signal transmission, is a model system for functional amyloid study. To compare the aggregation of functional and disease-causing amyloids, we previously synthesized a fluorine-labeled kassinin through solid-phase peptide …

Excited State Proton Transfer From Acidic Alcohols To A Quinoline Photobase Can Be Solvated By Non-Acidic Alcohol Solvents, Jonathan Ryan Hunt, Joseph Hecht, Clara Goolsby, Jade Hagihara, Monique Loza, Samantha Del Pozo

Chemistry and Biochemistry Faculty Works

Photobases are a type of molecule that become more basic upon photoexcitation and can therefore be used to control proton transfer reactions with light. The solvation requirements for excited state proton transfer (ESPT) in photobase systems is poorly understood, which limits their applicability. Here, we investigate the solvation of the ESPT reaction using 5-methoxyquinoline (MeOQ), a well-studied photobase with an excited state pKa (pKa*) of approximately 15.1, as a model system. Previous studies have shown that, in addition to the acidic donor that donates a proton to the photoexcited MeOQ, an additional “auxiliary donor” is necessary to solvate the resulting …

Emerging Chromatin Regulators In Response To Heavy Metal Exposure, Wesley Saintilnord

Theses and Dissertations--Molecular and Cellular Biochemistry

Environmental exposure to heavy metals poses significant threats to human health as they are associated with various developmental and chronic pathologies such as reproductive defects and cancers. Despite their profound risks, a comprehensive understanding of their disease-causing mechanisms is lacking. Most studies point to reactive oxygen species-induced DNA damage; however, their mutagenic potential is relatively weak suggesting the involvement of alternative mechanisms. One important, yet underexplored mechanism, is their ability to rewire the epigenome via DNA methylation and histone variant incorporation, leading to aberrant gene regulatory networks.

This study investigates the epigenetic mechanisms targeted by two ubiquitous heavy metals with …