Biochemistry, Biophysics, and Structural Biology Commons^™

Transcription Factor Binding And Discovery Of Novel Gene In The Opportunistic Human Pathogen, Pseudomonas Aeruginosa, Alaina Westee

Symposium of Student Scholars

Pseudomonas aeruginosa (PA) is a gram-negative, ubiquitously-found bacterium that primarily causes nosocomial, or hospital-borne, infections within immunocompromised patients. Therefore, it has been deemed a critical priority pathogen by the World Health Organization (WHO) and the Center for Disease Control (CDC), generating a need for research on its fundamental biology. The Van Dyke laboratory focuses on proteins called transcription factors, which promote or repress gene expression to regulate an organism’s functioning. We are specifically studying the cadmium-responsive transcription factor, CadR, due to the importance of metals in virulence and the lack of information on PA’s response to metal fluctuations. We intend …

Bloom: Behavioral Learning And Outcome Observation In Microbes, Sean Sarwar Haque, Luke Compton Wharton, Ming Lin, Razvan Voicu

Symposium of Student Scholars

Understanding how pathogens respond to physical changes in their environment is crucial for developing effective treatments and preventative measures. Current research often relies on static models or experimental data that either fail to capture the dynamic interactions within cellular environments or are not generalizable to other types of pathogens. This project aims to address this gap by creating a comprehensive cell simulation that models pathogens and their response to chemical, physical, and physiological changes. The proposed solution is a simulation that integrates biological data and computational modeling to replicate the behavior of pathogens in real time as they are affected …

A New Crispr System Uses Energy Storage Indiscriminately, Brendon Guinn

Research on Capitol Hill

CRISPR systems are Immune systems used by bacteria to defend against viruses. Recently, tools such as CRISPR Cas9 that are derived from CRISPR systems have been developed as a powerful tool to treat disease. 

Here we are studying a different CRISPR system related to the one used to develop the Cas9 tool. We study this system to discover new proteins that may be used to develop tools to cure diseases and diversify our arsenal of disease-fighting genetic sequences. 

In-Silico Modeling And Characterization Of Kcc2 Protein Interaction With A Small Molecule Direct Agonist Identifies Potential Binding Sites For Modulating Behaviors Associated With Substances Of Abuse, William Hai Dang Ho, Alfred Amendolara, Kenyon Mitchell, Jaden Miner, Ruth Northcott, Braxton Bingham, Andrew J. Payne

Annual Research Symposium

Purpose

KCC2 is a potassium-chloride cotransporter that plays a critical role in neuronal function by regulating GABAergic signaling via chloride gradients. Maintaining this concentration gradient is crucial for balancing excitation and inhibition in the brain. While KCC2 dysregulation has been implicated in epilepsy and seizures, recent studies suggest that KCC2 inhibition results in phenotypes mirroring those seen in chronic opioid dependence. As such, increasing evidence support KCC2 being a potential therapeutic target for modulating behaviors associated with substances of abuse. Currently, only a few direct small molecule agonists against KCC2 have been reported, and no definitive active site on the …

Use Of Synthetic Water-Soluble Kcc2 To Modulate Chloride Homeostasis In Cultured Dopamine-Neuron-Like Cells, Mason Terry, Andrew Payne, Dario Mizrachi

Annual Research Symposium

No abstract provided.

Probing The Stability Of Designed Protein, Axel Irianni, Shuvo Chakraborty, Maral Afshinpour

SDSU Data Science Symposium

Naturally occurring proteins have evolved to perform specific biochemical functions, and their amino acid sequences are optimized for those functions rather than for stability. Enhancing protein stability without compromising its function is highly desirable for biotechnological applications, such as vaccine design. Computational protein design algorithms offer a solution by making targeted amino acid changes to the native protein sequence, potentially enhancing stability without the need for the lengthy, labor-intensive, and costly experimental processes typically involved in stabilizing proteins. There are various categories of computational protein design algorithms, and it remains unclear which approach is the most effective. In this study, …

Single Amino Acid Changes Impact The Ability Of Drosophila Melanogaster Cecropins To Inhibit Growth Of Providencia Pathogens, Sarah Smith, Marla Forfar, Christopher Feudale, Lauren Shaffer, Grace Ginder, Marion Duval, Quinn Smith, Moria C. Chambers

Faculty Journal Articles

As antibiotic-resistant bacteria spread worldwide, the need to develop novel antimicrobial agents is urgent. One rich source of potential antimicrobials is the insect immune system, as insects produce a wide range of antimicrobial peptides (AMPs) with diverse sequences and structures. Insects also encounter many bacterial pathogens, some of which are closely related to pathogens of clinical relevance. However, despite interest in AMPs as therapeutics, the relationships between the amino acid sequence, biophysical properties, antimicrobial activity, and specificity are still not generalizable. To improve our understanding of these relationships, we assessed how single amino acid changes in cecropin AMPs produced by …

The Lc3-Interacting Region Of Nbr1 Is A Protein Interaction Hub Enabling Optimal Flux, Brian Joseph North

Dartmouth College Ph.D Dissertations

Autophagy is a highly conserved pathway that maintains cell health by breaking down and recycling cellular components such as protein aggregates or damaged organelles. During autophagy, potentially toxic cargo is enveloped by a newly formed autophagosome and trafficked to the lysosome for degradation. Ubiquitinated protein aggregates, a key target for autophagy, are identified by multiple autophagy receptors. NBR1 is an archetypal autophagy receptor and an excellent model for deciphering the role of the multivalent, heterotypic interactions made by cargo-bound receptors. Using NBR1 as a model, we find that three critical binding partners—ATG8-family proteins, FIP200, and TAX1BP1—each bind to a short …

Conformation And Membrane Topology Of The N-Terminal Ectodomain Of Influenza A M2 Protein, Kyra C. Roepke , '24, Kathleen P. Howard

Chemistry & Biochemistry Faculty Works

The N-terminal ectodomain of the influenza A M2 protein is a target for universal influenza vaccine development and novel antiviral strategies. Despite the significance of this domain, it is poorly understood and most structural studies of the M2 protein have disregarded the N-terminal ectodomain in their analyses. Here, we report conformational properties and describe insights into the membrane topology of sites along the N-terminal ectodomain. Full-length M2 protein is embedded in lipid bilayer nanodiscs and studied using site-directed spin labeling electron paramagnetic resonance spectroscopy. Results are consistent with a turn in the middle of the ectodomain that changes in proximity …

Inhibition Of Lysine Deacetylase Activity Impacts Formation Of The Vitamin D Receptor Activation Complex, Shannon Dwyer

Theses and Dissertations

The vitamin D endocrine system is responsible for the regulation of many biological processes including bone metabolism, calcium homeostasis, cell proliferation and cell differentiation. Alterations to the vitamin D signaling pathway are associated with several diseases including bone diseases, diabetes, cardiovascular diseases, autoimmune diseases, and cancer. Vitamin D precursors are chemically modified to become the biologically active hormone, calcitriol. Calcitriol binds to the vitamin D receptor (VDR), a member of the nuclear hormone receptor (NHR) superfamily. VDR forms a heterodimer with retinoid X receptor (RXR) and together they bind to promoters containing vitamin D response elements (VDREs) to activate transcription …

Ivy Proteins As Guardians Of Bacterial Cell Wall Integrity: Regulation Of Lytic Transglycosylases Explored, Aamna Aijaz, Trinity E. Alamutu, Vy T. Dao, Nathaniel R. Davis, Michael D. Landers, Nykolas K. Mackevicius, Liliana Ortiz, Irina F. Padilla-Montoya, Kacy J. Smith, Maria L. Snyder, Anthony J. Stefanie, Blaise M. Williams, Thomas C. Leeper

The Kennesaw Journal of Undergraduate Research

Lytic transglycosylases (LTs) are bacterial enzymes involved in biosynthesis and maintenance of the peptidoglycan cell wall. LTs are reported to be regulated by two paralogs of Inhibitor of Vertebrate Lysozymes: Ivyp1 and Ivyp2. This study investigated the regulatory dynamics between the soluble LT (SltB1), and Ivy paralogs as putative regulators in Pseudomonas aeruginosa (PA). The secondary objective was to delineate the critical roles played by a glutamic acid at position 135 in SltB1 and a histidine at position 62 in Ivyp1 in governing their molecular interaction through site directed mutagenesis. Isolated SltB1 shows no lytic activity in our assay, in …

Gdp-Mannose 4,6-Dehydratase Is A Key Driver Of Mycn-Amplified Neuroblastoma Core Fucosylation And Tumorigenesis, Beibei Zhu, Michelle G. Pitts, Michael D. Buoncristiani, Lindsay T. Bryant, Oscar Lopez-Nunez, Juan P. Gurria, Cameron Shedlock, Roberto Ribas, Shannon Keohane, Jinpeng Liu, Chi Wang, Matthew S. Gentry, Nathan R. Shelman, Derek B. Allison, B. Mark Evers, Ramon C. Sun, Eric J. Rellinger

Markey Cancer Center Faculty Publications

MYCN-amplification is a genetic hallmark of ~40% of high-risk neuroblastomas (NBs). Altered glycosylation is a common feature of adult cancer progression, but little is known about how genetic signatures such as MYCN-amplification alter glycosylation profiles. Herein, matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) revealed increased core fucosylated glycan abundance within neuroblast-rich regions of human MYCN-amplified NB tumors. GDP-mannose 4,6-dehydratase (GMDS) is responsible for the first-committed and rate-limiting step of de novo GDP-fucose synthesis. High GMDS expression was found to be associated with poor patient survival, advanced stage disease, and MYCN-amplification in human NB tumors. Chromatin immunoprecipitation and promoter reporter assays …

A Microrna-Regulated Transcriptional State Defines Intratumoral Cd8+ T Cells That Respond To Immunotherapy, William W. Tang, Ben Battistone, Kaylyn M. Bauer, Allison M. Weis, Cindy Barba, Muhammad Zaki Hidayatullah Fadlullah, Arevik Ghazaryan, Van B. Tran, Soh-Hyun Lee, Z. Busra Agir, Morgan C. Nelson, Emmanuel Stephen Victor, Amber Thibeaux, Colton Hernandez, Jacob Tantalla, Aik C. Tan, Dinesh Rao, Matthew Williams, Micah J. Drummond, Ellen J. Beswick, June L. Round, H. Atakan Ekiz, Warren P/ Voth, Ryan M. O’Connell

Markey Cancer Center Faculty Publications

The rising incidence of advanced-stage colorectal cancer (CRC) and poor survival outcomes necessitate new and effective therapies. Immune checkpoint inhibitors (ICIs), specifically anti-PD-1 therapy, show promise, yet clinical determinants of a positive response are suboptimal. Here, we identify microRNA-155 (miR-155) as necessary for CD8 + T cell-infiltrated tumors through an unbiased in vivo CRISPR-Cas9 screen identifying functional tumor antigen-specific CD8+ T cell-expressed microRNAs. T cell miR-155 is required for anti-PD-1 responses and for a vital intratumor CD8 + T cell differentiation cascade by repressing Ship-1, inhibiting Tcf-1 and stemness, and subsequently enhancing Cxcr6 expression, anti-tumor immunity, and effector functions. Based …

Staying Sane In The Membrane: Neutral Sphingomyelinase 2 As A Master Regulator Of Plasma Membrane Ceramide, Zainuddin Quadri, Erhard Bieberich

Markey Cancer Center Faculty Publications

Ceramide, a key signaling sphingolipid in the plasma membrane, plays a pivotal role in fundamental cellular processes such as adhesion, polarity, and programmed cell death. The generation of plasma membrane ceramide is largely attributed to the activity of two types of sphingomyelinases: neutral sphingomyelinase 2 (nSMase2, Smpd3) and acid sphingomyelinase (aSMase, Smpd1). While many studies have explored ceramide generation following experimental activation of these enzymes, the mechanisms governing basal or steady- state ceramide levels have remained poorly understood. Using an innovative mass spectrometry approach developed in the Canals’ lab, the team has quantified the distinct contributions of nSMase2 and aSMase …

Gdp-Mannose 4,6-Dehydratase Is A Key Driver Of Mycn- Amplified Neuroblastoma Core Fucosylation And Tumorigenesis, Beibei Zhu, Michelle G. Pitts, Michael D. Buoncristiani, Lindsay T. Bryant, Oscar Lopez-Nunez, Juan P. Gurria, Cameron Shedlock, Roberto Ribas, Shannon Keohane, Jinpeng Liu, Chi Wang, Matthew S. Gentry, Nathan R. Shelman, Derek B. Allison, B. Mark Evers, Ramon C. Sun, Eric J. Rellinger

Markey Cancer Center Faculty Publications

MYCN-amplification is a genetic hallmark of ~40% of high-risk neuroblastomas (NBs). Altered glycosylation is a common feature of adult cancer progression, but little is known about how genetic signatures such as MYCN-amplification alter glycosylation profiles. Herein, matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) revealed increased core fucosylated glycan abundance within neuroblast-rich regions of human MYCN-amplified NB tumors. GDP-mannose 4,6-dehydratase (GMDS) is responsible for the first-committed and rate-limiting step of de novo GDP-fucose synthesis. High GMDS expression was found to be associated with poor patient survival, advanced stage disease, and MYCN-amplification in human NB tumors. Chromatin immunoprecipitation and promoter reporter assays …

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 …

Taming Biological Complexity Through The Use Of Symmetries, Luis A. Álvarez-García

Dissertations, Theses, and Capstone Projects

The study of biological systems is, inherently, the study of very complex systems. This is essentially due to the fact that they are made up of numerous, often very complicated, interactions between an extensive number of components. Often necessitating an abundance of quantitative parameters and details for a precise description. The human brain for ex- ample, consisting of ∼ 80 billion neurons with ∼ 800 to 100 trillion connections between them, each of them depending on a large set of parameters. Even simpler examples such as bacterial organisms, such as E. coli and B. subtilis, which we focus on …

Solvation Thermodynamic Mapping Approaches For Computer-Aided Drug Discovery, Vjay Molino

Dissertations, Theses, and Capstone Projects

The drug discovery process is inherently long and costly, prompting the development and integration of computational tools to mitigate these challenges. One of area explored in computer-aided drug discovery is to understand the role of solvation in protein-drug binding and to develop computational tools and methods that can be integrated in the drug discovery process. Grid Inhomogeneous Solvation Theory (GIST) is a tool that provides a framework for mapping solvation thermodynamiproperties of water molecules on the protein surface.This thesis explores the use of GIST in generating pharmacophore models and elucidates the role of solvation in protein structural fluctuations.

One of …

Attenuation Of Vitamin E On Haloxyfop-R-Methyl Ester-Induced Hepatic Oxidative Stress In Orally Exposed Rats., Omolara D. Falodun

STEM for Success Resources

No abstract provided.

Genome-Wide Profiling Of Trna Modifications By Induro-Trnaseq Reveals Coordinated Changes, Yuko Nakano, Howard Gamper, Henri Mcguigan, Sunita Maharjan, Jiatong Li, Zhiyi Sun, Erbay Yigit, Sebastian Grünberg, Keerthana Krishnan, Nan-Sheng Li, Joseph Piccirilli, Ralph Kleiner, Nicole Nichols, Brian Gregory, Ya-Ming Hou

Department of Biochemistry and Molecular Biology Faculty Papers

While all native tRNAs undergo extensive post-transcriptional modifications as a mechanism to regulate gene expression, mapping these modifications remains challenging. The critical barrier is the difficulty of readthrough of modifications by reverse transcriptases (RTs). Here we use Induro-a new group-II intron-encoded RT-to map and quantify genome-wide tRNA modifications in Induro-tRNAseq. We show that Induro progressively increases readthrough over time by selectively overcoming RT stops without altering the misincorporation frequency. In a parallel analysis of Induro vs. a related RT, we provide comparative datasets to facilitate the prediction of each modification. We assess tRNA modifications across five human cell lines and …

Structure And Mechanism Of Biosynthesis Of Streptococcus Mutans Cell Wall Polysaccharide., Jeffrey S. Rush, Svetlana Zamakhaeva, Nicholas R Murner, Pan Deng, Andrew J Morris, Cameron W Kenner, Ian Black, Christian Heiss, Parastoo Azadi, Konstantin V Korotkov, Göran Widmalm, Natalia Korotkova

Molecular and Cellular Biochemistry Faculty Publications

Streptococcus mutans, the causative agent of human dental caries, expresses a cell wall attached Serotype c-specific Carbohydrate (SCC) that is critical for cell viability. SCC consists of a polyrhamnose backbone of →3)α-Rha(1 → 2)α-Rha(1→ repeats with glucose (Glc) side-chains and glycerol phosphate (GroP) decorations. This study reveals that SCC has one predominant and two more minor Glc modifications. The predominant Glc modification, α-Glc, attached to position 2 of 3-rhamnose, is installed by SccN and SccM glycosyltransferases and is the site of the GroP addition. The minor Glc modifications are β-Glc linked to position 4 of 3-rhamnose installed by SccP and …

Fast 3d Printing Of Fine, Continuous, And Soft Fibers Via Embedded Solvent Exchange, Wonsik Eom, Mohammad Tanver Hossain, Vidush Parasramka, Jeongmin Kim, Ryan W. Y. Siu, Kate A. Sanders, Dakota Piorkowski, Andrew Lowe, Hyun Gi Koh, Michael F. L. De Volder, Douglas S. Fudge, Randy H. Ewoldt, Sameh H. Tawfick

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Nature uses fibrous structures for sensing and structural functions as observed in hairs, whiskers, stereocilia, spider silks, and hagfish slime thread skeins. Here, we demonstrate multi-nozzle printing of 3D hair arrays having freeform trajectories at a very high rate, with fiber diameters as fine as 1.5 µm, continuous lengths reaching tens of centimeters, and a wide range of materials with elastic moduli from 5 MPa to 3500 MPa. This is achieved via 3D printing by rapid solvent exchange in high yield stress micro granular gel, leading to radial solidification of the extruded polymer filament at a rate of 2.33 μm/s. …

Retracted: Conserved Domains In Promoters Of Differentially Expressed Genes: How To Find Them And What Can They Tell Us?, Emalynn E. Tobias

Mako: NSU Undergraduate Student Journal

THIS ARTICLE HAS BEEN RETRACTED DUE TO THE FOLLOWING REASON: inadvertent errors in several citations.

The complex process of regulating gene expression involves a large number of cis- and trans-acting components. The cis elements also referred to as cis regulatory elements (CREs) are highly conserved across species, and are often referred to as conserved domains mainly located in the promoters of genes. The trans acting sequences such as enhancers, moderators and insulators are also crucial in the regulation of gene expression. With an increased influx of genomic and transcriptomic data, study of differentially expressed genes (DEGs) is highly effective in …

Associations Between Social Determinants Of Health And Mental Health Disorders Among U.S. Population: A Cross-Sectional Study, S. Tanarsuwongkul

Faculty Publications

Aims

The impact of social determinants of health (SDOH) on mental health is increasingly realized. A comprehensive study examining the associations of SDOH with mental health disorders has yet to be accomplished. This study evaluated the associations between five domains of SDOH and the SDOH summary score and mental health disorders in the United States.

Methods

We analyzed data from a diverse group of participants enrolled in the All of Us research programme, a research programme to gather data from one million people living in the United States, in a cross-sectional design. The primary exposure was SDOH based on Healthy …

Tdp43 Autoregulation Gives Rise To Dominant Negative Isoforms That Are Tightly Controlled By Transcriptional And Post-Translational Mechanisms, Megan M. Dykstra, Kaitlin Weskamp, Nicolás B. Gómez, Jacob Waksmacki, Elizabeth Tank, M. Rebecca Glineburg, Allison Snyder, Emile Pinarbasi, Michael Bekier, Xingli Li, Morgan R. Miller, Jen Bai, Shameena Shahzad, Neha Nedumaran, Clare Wieland, Corey Stewart, Sydney Willey, Nikolas Grotewold, Jonathon Mcbride, John J. Moran, Aditya V. Suryakumar, Michael Lucas, Peter M. Tessier, Michael Ward, Peter K. Todd, Sami J. Barmada

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The nuclear RNA-binding protein TDP43 is integrally involved in the pathogenesis of amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). Previous studies uncovered N-terminal TDP43 isoforms that are predominantly cytosolic in localization, prone to aggregation, and enriched in susceptible spinal motor neurons. In healthy cells, however, these shortened (s)TDP43 isoforms are difficult to detect in comparison to full-length (fl)TDP43, raising questions regarding their origin and selective regulation. Here, we show that sTDP43 is created as a by-product of TDP43 autoregulation and cleared by nonsense-mediated RNA decay (NMD). sTDP43-encoding transcripts that escape NMD are rapidly degraded post-translationally via the proteasome …

Sialylation Of Tnfr1 By St6gal1 Modulates Receptor Dynamics And Determines Cell Fate, Jihye Hwang

All ETDs from UAB

Abnormal glycosylation has long been identified as a key feature of cancer. Aberrant glycan structures on tumor cells arise from the dysregulation of select glycosyltransferases. For example, sialyltransferase ST6GAL1 is notable for its high expression in various cancers, including breast, colon, ovarian, and pancreatic. ST6GAL1 introduces α2-6-linkage sialylation to N-glycans on proteins, endowing cancer cells with stem cell-like properties. This modification contributes to resistance to apoptosis mediated by death receptors like TNFR1. Despite its significance in cancer, the regulatory mechanisms controlling ST6GAL1 expression remain largely unexplored. Additionally, it is unclear whether the apoptosis-resistant effect of sialylation is caused by an …

Characterizing The Molecular Complexities Of Iga1 By Serum Proteomics In The Context Of Iga Nephropathy, Mary A. Cunningham

All ETDs from UAB

Immunoglobulin A1 (IgA1) is the second most abundantly produced immunoglobulin in circulation per day and plays a key role in human immunity. Two molecular complexities of IgA1 make accurately studying the protein challenging. The first is that IgA1 exists in three main molecular forms in the serum of humans: monomeric (mIgA1, 80-90% of serum IgA1), polymeric (pIgA1, 10-20% of serum IgA1), and IgA1-containing immune complexes (IgA1-IC, <0.5% of serum IgA1). The second complexity is that the hinge-region of IgA1 is extensively O-glycosylated and exhibits a high level of variation in its O-glycans, particularly in the degree of sialylation. In context of the autoimmune disease IgA nephropathy (IgAN), patients have elevated levels of IgA1 that has reduced levels of galactose (Gal) in the IgA1 hinge-region (Gal-deficient IgA1). This Gal-deficient IgA1 forms immune complexes with IgG autoantibodies (IgA1-IC), deposits in the glomeruli, and induces kidney injury. While it is established that these large IgA1-IC (>700 kDa) formed in the circulation are pathogenic, there remains a gap in knowledge about other blood proteins that may be associating with IgA1 in complexes. It is also necessary to understand the native …

Mechanistic Insights Of Translational Readthrough To Suppress Nonsense Mutations, Kari Thrasher

All ETDs from UAB

A nonsense mutation is a point mutation in DNA that gives rise to a premature termination codon (PTC) in the open reading frame of the transcribed mRNA. Translation of this PTC-containing transcript terminates prematurely, leading to the creation of truncated non-functional protein. Translational readthrough is one therapeutic option being explored to suppress nonsense mutations that cause disease. Here, we further elucidate amino acid incorporation and the functional consequences of readthrough of nonsense mutations that cause cystic fibrosis. Additionally, we reveal the molecular mechanisms activated by a recently described small molecule readthrough agent, SRI- 41315. Finally, we discuss the various therapeutic …

Characterization Of The Roles Of U1-70k In Alternative Splicing And Nuclear Speckle Formation, Trenton Myers Paul

All ETDs from UAB

RNA-binding proteins (RBPs) play critical roles in RNA processing and regulation. Among these RBPs, U1-70K is a key protein involved in RNA processing, nuclear speckle formation, and has implications in neurodegenerative diseases such as Alzheimer's. Despite its significance in transcription, RNA processing, nuclear speckle formation, and nonsense-mediated decay, studies on U1-70K have been limited primarily to its well-structured N-terminal domain due to challenges in solubilizing and expressing the full-length protein. In this dissertation, we address these challenges by optimizing cell strain and co expressing DnaK and DnaJ, enabling the successful expression, solubilization, and purification of full-length U1-70K. Using fluorescence polarization …

Controlled By Disorder: Modifications To An Unstructured C-Terminal Region Alter Srsf1'S Intramolecular Interactions And Tendency To Phase Separate, Talia Fargason

All ETDs from UAB

The protein Serine-Arginine-rich Splicing Factor 1 (SRSF1) is essential in multiple stages of the mRNA lifecycle, including alternative splicing, nonsense-mediated decay, and nuclear export. SRSF1’s dysfunction is linked to cancers, viral evasion, and developmental disorders. Its function depends on interactions between structured and unstructured regions, modulated by phosphorylation. However, the unstructured regions, while critical for regulation, contribute to protein insolubility, hindering full-length studies. Prior to the work presented here, structural studies of SRSF1 were limited to analysis of its isolated domains. This dissertation develops new techniques to characterize SRSF1, focusing on its intermolecular interactions driving phase separation and intramolecular interactions …