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Articles 121 - 150 of 1544

Full-Text Articles in Biochemistry

Redox Control In A Fused Electron Transfer Flavoprotein From A Thermophilic Archaeon And Expanded Significance Of A Hydrogen Bond From A Conserved Histidine Residue That Contributes To Flavin Redox Tuning And Activation For Covalent Modification, Debarati Das Jan 2025

Redox Control In A Fused Electron Transfer Flavoprotein From A Thermophilic Archaeon And Expanded Significance Of A Hydrogen Bond From A Conserved Histidine Residue That Contributes To Flavin Redox Tuning And Activation For Covalent Modification, Debarati Das

Theses and Dissertations--Chemistry

In absence of O2 as terminal electron acceptors in anaerobic bacteria and archaea, carbohydrate metabolism is 15 times less efficient compared to aerobic energy metabolism resulting in energy deficit conditions. Despite their meager resources these anaerobes were able to generate H2 and a chemiosmotic potential able to drive energy demanding reactions such as CO2 or N2 fixation. These observations raised concerns as production of high energy reductants (H2) from mediocre fuels (NADH) defied the laws of thermodynamics.

In 2008, a known mechanism “electron bifurcation” but with flavins as redox mediators instead of quinones was …


P23h Rhodopsin Accumulation Disrupts Synaptic Protein Levels In Rod Photoreceptors, Samantha Thompson Jan 2025

P23h Rhodopsin Accumulation Disrupts Synaptic Protein Levels In Rod Photoreceptors, Samantha Thompson

Graduate Theses, Dissertations, and Problem Reports (ETD)

Rod photoreceptors are specialized neurons located in the retina, the neural tissue that lines the back of the eye. Rod photoreceptors are necessary for dim light and peripheral vision through the photoactivation rhodopsin (Rho). Rho is synthesized in the inner segment of rods before being unidirectionally trafficked to the outer segment. In diseases such as retinitis pigmentosa (RP), Rho trafficking can be disrupted, leading to progressive rod cell death. In many cases of RP, Rho is mislocalized to the rod photoreceptor synapse (“spherule”). The impact of Rho mislocalization on spherule structure and protein organization is poorly understood. We hypothesize that …


Characterizing The Targeting Of Toc159 Receptors To The Chloroplast Outer Envelope Membrane And Their Role In The Assembly Of Distinct Toc Complexes, Michael Fish Jan 2025

Characterizing The Targeting Of Toc159 Receptors To The Chloroplast Outer Envelope Membrane And Their Role In The Assembly Of Distinct Toc Complexes, Michael Fish

Theses and Dissertations (Comprehensive)

Global agriculture and food security face challenges from climate change, population growth, and other human-driven pressures. Enhancing our understanding of plant biology, particularly chloroplast function, is critical for improving crop yield and stress resilience. As the sites of photosynthesis and key regulators of plant responses to environmental cues, chloroplasts depend on the precise import of thousands of nuclear-encoded proteins to maintain their biogenesis and function. While much is known about the core translocon components in the chloroplast outer envelope membrane that form the TOC complex, the mechanisms underlying their targeting, assembly, and regulation remain incompletely understood.

Plastids, including chloroplasts, evolved …


Reversible Degradation Of Peptidoglycan By Lytic Transglycosylases, Aaron Devereaux Jan 2025

Reversible Degradation Of Peptidoglycan By Lytic Transglycosylases, Aaron Devereaux

Theses and Dissertations (Comprehensive)

Antimicrobial resistance continues to be a burden on the global healthcare system with an estimated cost of billions of dollars and millions of deaths each year. Recently, there has been little to no development on new antibiotics to treat bacterial infection, and any that are developed become resisted to within a few years. Both Gram-positive and Gram-negative bacteria contain a mesh-like layer called peptidoglycan (PG) that surrounds their cells providing strength, cell shape, and protection from their environments. This layer is a polymer of N-acetylmuramic acid (MurNAc) and N-acetylglucosamine (GlcNAc) connected via a b-1,4-glycosidic bond, with each strand being cross-linked …


Structural Insights Into Peptidoglycan O-Acetylation In Gram-Negative Bacteria, Tyler Malloch Jan 2025

Structural Insights Into Peptidoglycan O-Acetylation In Gram-Negative Bacteria, Tyler Malloch

Theses and Dissertations (Comprehensive)

The Centres for Disease Control has acknowledged that we are entering a post-antibiotic era, where increasing numbers of bacterial pathogens are becoming resistant to known antibiotics. One of the most successfully targeted features of bacteria is also the main component of the cell wall, peptidoglycan (PG). PG is a heteropolymer of alternating sugar residues, namely N-acetylmuramic acid (MurNAc) and N-acetylglucosamine (GlcNAc) which are joined together by b-(1,4)-glycosidic bonds and crosslinked via stem peptide chains. PG is a target, readily lysed by exogenous and endogenous autolysins, such as lysozyme and lytic transglycosylase, respectively. This event leads to cell death …


Exploring The Interconnections Between Mitochondrial Carrier Proteins Involved In Energy Transfer: The Case Of Uncouplig Proteins 2 And 4, Adenine Nucleotide Translocase, And Phosphate Translocase, Marzieh Tabefam Jan 2025

Exploring The Interconnections Between Mitochondrial Carrier Proteins Involved In Energy Transfer: The Case Of Uncouplig Proteins 2 And 4, Adenine Nucleotide Translocase, And Phosphate Translocase, Marzieh Tabefam

Theses and Dissertations (Comprehensive)

Mitochondrial carrier (MC) proteins play an essential role in cellular energy metabolism by mediating the transport of solutes and protons across the mitochondrial inner membrane (MIM). This thesis explores the structural and functional characteristics of three groups of MC proteins—Uncoupling Proteins (UCPs), Adenine Nucleotide Translocase (ANT), and Phosphate Translocase (PiT)—to elucidate their individual and interrelated cooperative roles in mitochondrial proton transport and energy regulation.

The study develops and applies novel methodologies for the overexpression, purification, and reconstitution of MC proteins into model lipid bilayers mimicking the native mitochondrial inner membrane environment. These methods ensure proteins maintain their native-like …


Interactions Of The Sars-Cov-2 Viral Genome 3’-Untranslated Region With Viral And Host Rnas, Caleb Frye, Mihaela Rita Mihailescu Dec 2024

Interactions Of The Sars-Cov-2 Viral Genome 3’-Untranslated Region With Viral And Host Rnas, Caleb Frye, Mihaela Rita Mihailescu

Electronic Theses and Dissertations

This dissertation focuses on the characterization of RNA-RNA interactions within the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genome and with host microRNAs. As the causative agent of coronavirus disease 2019 (COVID-19), SARS-CoV-2 has evolved rapidly since its appearance. This has warranted prompt characterization of the virus particularly of its single stranded RNA (ssRNA) genome. By using a combination of bioinformatics, biophysics, and/or biological assays, we analyzed the SARS-CoV-2 viral genomic RNA and uncovered interactions of genomic RNA with host RNAs, highlighting an underutilized method of targeting RNA viruses. We showed here that the conserved elements in the viral genomic …


P85Α Degradation Mediated By Ubiquitin E3 Ligase Fbxo21 Offers Therapeutic Potential In Leukemia, Kasidy K. Weber Dec 2024

P85Α Degradation Mediated By Ubiquitin E3 Ligase Fbxo21 Offers Therapeutic Potential In Leukemia, Kasidy K. Weber

Theses & Dissertations

Acute myeloid leukemia (AML) is a complex and heterogeneous disease characterized by the clonal expansion of myeloid blasts in the bone marrow. Despite significant therapeutic advances over the years, the prognosis for AML patients remains dismal, with high relapse rates and poor overall survival. The ubiquitin-proteasome system (UPS) plays a critical role in maintaining cellular homeostasis by regulating the degradation of proteins involved in essential processes such as cell cycle control, DNA repair, apoptosis, and various signaling pathways. Given this vital function, targeting ubiquitin E3 ligases within the UPS presents a promising strategy for developing more effective and targeted therapies …


A Kinetic Model For Compound Heterozygous Pathogenic Variants In Tyrosyl-Trna Synthetase Gene Yars2-Associated Neonatal Phenotype, Thomas W Christian, Sunita Maharjan, Sitao Yin, Yuka Yamaki, Isao Masuda, Fenglin Li, Colleen Muraresku, Sheila Clever, Rebecca Ganetzky, Ya-Ming Hou Dec 2024

A Kinetic Model For Compound Heterozygous Pathogenic Variants In Tyrosyl-Trna Synthetase Gene Yars2-Associated Neonatal Phenotype, Thomas W Christian, Sunita Maharjan, Sitao Yin, Yuka Yamaki, Isao Masuda, Fenglin Li, Colleen Muraresku, Sheila Clever, Rebecca Ganetzky, Ya-Ming Hou

Department of Biochemistry and Molecular Biology Faculty Papers

Human genetic disorders are often caused by mutations of compound heterozygosity, where each allele of the mutant gene harbors a different genetic lesion. However, studies of such mutations are hampered due to the lack of an appropriate model. Here we describe a kinetic model of compound heterozygous variants in an obligate enzyme dimer that contains one mutation in one monomer and the other mutation in the second monomer. This enzyme is encoded by human YARS2 for mitochondrial tyrosyl-tRNA synthetase (mt-TyrRS), which aminoacylates tyrosine to mt-tRNATyr. YARS2 is a member of the genes for mt-aminoacyl-tRNA synthetases, where pathogenic mutations …


Angiogenin-Catalyzed Cleavage Within Trna Anticodon-Loops Identified By Cp-Rna-Seq, Megumi Shigematsu, Ryuma Matsubara, Justin Gumas, Takuya Kawamura, Yohei Kirino Dec 2024

Angiogenin-Catalyzed Cleavage Within Trna Anticodon-Loops Identified By Cp-Rna-Seq, Megumi Shigematsu, Ryuma Matsubara, Justin Gumas, Takuya Kawamura, Yohei Kirino

Computational Medicine Center Faculty Papers

Angiogenin (Ang), an endoribonuclease belonging to the RNase A superfamily, cleaves the anticodon-loops of tRNAs to produce tRNA-half molecules. Although previous studies have demonstrated the involvement of Ang in the pathobiology of neurodegenerative disorders, the characterization of Ang-generated tRNA halves in neuronal cells remains limited. This is partly due to the technical limitations of standard RNA-seq methods, which cannot capture Ang-generated RNAs containing a 2',3'-cyclic phosphate (cP). In this report, we established an Ang-treatment model using SH-SY5Y, a human neuroblastoma cell line, and demonstrated Ang-dependent accumulation of tRNA halves. By performing cP-RNA-seq, which selectively captures cP-containing RNAs, we identified Ang-generated …


Polymeric Sumo-2/3 Chain Signals Are Antagonistically Regulated By The Sumo-Targeted Ubiquitin E3 Ligase Rnf4 And The Sumo-Specific Isopeptidase Senp6, Shaniah A. Irving M.A., Xiang-Dong Zhang Ph.D. Dec 2024

Polymeric Sumo-2/3 Chain Signals Are Antagonistically Regulated By The Sumo-Targeted Ubiquitin E3 Ligase Rnf4 And The Sumo-Specific Isopeptidase Senp6, Shaniah A. Irving M.A., Xiang-Dong Zhang Ph.D.

Biology Theses

Polymeric SUMO-2/3 chain modification is critical for chromosome segregation, DNA damage repair, genome stability, stress responses, and protein degradation. However, how these signals are regulated remains poorly understood. Both the SUMO-targeted ubiquitin E3 ligase (STUbL) RNF4 and the SUMO-specific isopeptidase SENP6 recognize poly-SUMO-2/3 chains through multiple SUMO-interacting motifs (SIMs). RNF4 contains four tandem SIMs within a short (~80 amino acids) region, whereas SENP6 possesses eight SIMs spanning a much larger (~500 amino acids) domain.

Our preliminary results show that overexpressing an RNF4 N-terminal fragment containing four tandem SIMs (wild type, WT), but not an inactive SIMs mutant (Mut), increases levels …


Decoding Fgf/Fgfr Signaling: Insights Into Biological Functions And Disease Relevance, Oshadi Edirisinghe, Gaetane Ternier, Zeina Alraawi, Thallapuranam Krishnaswamy Suresh Kumar Dec 2024

Decoding Fgf/Fgfr Signaling: Insights Into Biological Functions And Disease Relevance, Oshadi Edirisinghe, Gaetane Ternier, Zeina Alraawi, Thallapuranam Krishnaswamy Suresh Kumar

Chemistry & Biochemistry Faculty Publications and Presentations

Fibroblast Growth Factors (FGFs) and their cognate receptors, FGFRs, play pivotal roles in a plethora of biological processes, including cell proliferation, differentiation, tissue repair, and metabolic homeostasis. This review provides a comprehensive overview of FGF-FGFR signaling pathways while highlighting their complex regulatory mechanisms and interconnections with other signaling networks. Further, we briefly discuss the FGFs involvement in developmental, metabolic, and housekeeping functions. By complementing current knowledge and emerging research, this review aims to enhance the understanding of FGF-FGFR-mediated signaling and its implications for health and disease, which will be crucial for therapeutic development against FGF-related pathological conditions.


Traittrainr: Accelerating Large-Scale Simulation Under Models Of Continuous Trait Evolution, Jenniffer Roa Lozano, Mataya Duncan, Duane D. Mckenna, Todd A. Castoe, Michael Degiorgio, Richard Adams Dec 2024

Traittrainr: Accelerating Large-Scale Simulation Under Models Of Continuous Trait Evolution, Jenniffer Roa Lozano, Mataya Duncan, Duane D. Mckenna, Todd A. Castoe, Michael Degiorgio, Richard Adams

Entomology and Plant Pathology Faculty Publications and Presentations

Abstract

Motivation

The scale and scope of comparative trait data are expanding at unprecedented rates, and recent advances in evolutionary modeling and simulation sometimes struggle to match this pace. Well-organized and flexible applications for conducting large-scale simulations of evolution hold promise in this context for understanding models and more so our ability to confidently estimate them with real trait data sampled from nature. Results

We introduce TraitTrainR, an R package designed to facilitate efficient, large-scale simulations under complex models of continuous trait evolution. TraitTrainR employs several output formats, supports popular trait data transformations, accommodates multi-trait evolution, and exhibits flexibility …


The Effects Of Mosaicism On Biological And Clinical Markers Of Alzheimer's Disease In Adults With Down Syndrome, Laura Xicota, Lam-Ha T. Dang, Alice Lee, Sharon Krinsky-Mchale, Deborah Pang, Lisa Melilli, Sid E. O’Bryant, Rachel L. Henson, Charles Laymon, Florence Lai, H. Diana Rosas, Beau Ances, Ira Lott, Christy Hom, Bradley Christian, Sigan Hartley, Shahid Zaman, Elizabeth Head, Mark Mapstone, Zhezhen Jin, Wayne Silverman, Nicole Schupf, Benjamin Handen, Joseph H. Lee, Alzheimer’S Biomarker Consortium – Down Syndrome (Abc-Ds) Dec 2024

The Effects Of Mosaicism On Biological And Clinical Markers Of Alzheimer's Disease In Adults With Down Syndrome, Laura Xicota, Lam-Ha T. Dang, Alice Lee, Sharon Krinsky-Mchale, Deborah Pang, Lisa Melilli, Sid E. O’Bryant, Rachel L. Henson, Charles Laymon, Florence Lai, H. Diana Rosas, Beau Ances, Ira Lott, Christy Hom, Bradley Christian, Sigan Hartley, Shahid Zaman, Elizabeth Head, Mark Mapstone, Zhezhen Jin, Wayne Silverman, Nicole Schupf, Benjamin Handen, Joseph H. Lee, Alzheimer’S Biomarker Consortium – Down Syndrome (Abc-Ds)

Neurology Faculty Publications

Background Individuals with Down syndrome (DS) are at high risk of early-onset Alzheimer’s disease (AD); yet, some 20 percent do not develop any signs of dementia until after 65 years or in their lifetime. Mosaicism could contribute to this phenotypic variation, where some disomic cells could lead to lower levels of gene products from chromosome 21.

Methods We examined longitudinal neuropsychological and biomarker data from two large studies of DS: the Alzheimer Biomarker Consortium–Down syndrome study (ABC-DS) (n = 357); and a legacy study (n = 468). We assessed mosaicism using karyotyping or GWAS data. Participants had data on plasma …


Independent Evolution Of Oleate Hydratase Clades In Bacillales Reflects Molecular Convergence, Robert J. Neff, Priscilla C. Lages, Shannon K. Donworth, James D. Brien, Christopher D. Radka Dec 2024

Independent Evolution Of Oleate Hydratase Clades In Bacillales Reflects Molecular Convergence, Robert J. Neff, Priscilla C. Lages, Shannon K. Donworth, James D. Brien, Christopher D. Radka

Markey Cancer Center Faculty Publications

Oleate hydratase (OhyA), a flavoenzyme that catalyzes the hydration of unsaturated fatty acids, has been identified in various Bacillales organisms, including those in the Listeria, Lysinibacillus, Paenibacillus, and Staphylococcus genera. In this study, we combine structural biology with molecular and phylogenetic analyses to investigate the evolutionary dynamics of the OhyA protein family within the Bacillales order. Our evolutionary analysis reveals two distinct OhyA clades (clade I and clade II) within Bacillales that, while sharing catalytic function, exhibit significant genomic and structural differences. Our findings suggest that these OhyA clades originated from independent evolutionary processes through convergent evolution rather than gene …


Characterization Of An Acetogenin-Carrying Nanosuspension And Its Effect On Bacteria Of Interest In The Poultry Industry, Brandon A. Lopez-Romero, Gabriela Aguilar-Hernandez, Billy M. Hargis, Maria De Lourdes Garcia-Magana, Ulises M. Lopez-Garcia, Rosa I. Ortiz-Basurto, Adalberto Zamudio-Ojeda, Juan D. Latorre, Efigenia Montalvo-Gonzalez Dec 2024

Characterization Of An Acetogenin-Carrying Nanosuspension And Its Effect On Bacteria Of Interest In The Poultry Industry, Brandon A. Lopez-Romero, Gabriela Aguilar-Hernandez, Billy M. Hargis, Maria De Lourdes Garcia-Magana, Ulises M. Lopez-Garcia, Rosa I. Ortiz-Basurto, Adalberto Zamudio-Ojeda, Juan D. Latorre, Efigenia Montalvo-Gonzalez

Poultry Science Faculty Publications and Presentations

This work aimed to develop a nanosuspension (NSps) as an acetogenin (ACGs) carrier, using soy lecithin (SL) and hydroxypropyl-β-cyclodextrin (βCD) named NSps-βCDSL-ACGs. It was characterized by various spectroscopic techniques (DLS, FTIR, UV-vis diffuse reflectance). Moreover, the NSps morphology was observed by transmission electron microscopy (TEM). Also, the antibacterial activity of NSps-βCDSL-ACGs was evaluated against strains of interest in the poultry sector. NSps-βCDSL-ACGs presented nanometric size (207–239 nm), acceptable polydispersity index (PDI) values (0.13–0.17) and a high Z potential value (−47.17–50.36 mV), demonstrating high stability. The presence of ACGs in NSps-βCDSL-ACGs was confirmed by FTIR analysis. The nanoparticles had a spherical …


Assessing The Bioactivity Of Salvia Phytochemicals Against Breast Cancers, Allison C. Portaro, Jared L. Scott, David J. Schultz Nov 2024

Assessing The Bioactivity Of Salvia Phytochemicals Against Breast Cancers, Allison C. Portaro, Jared L. Scott, David J. Schultz

The Cardinal Edge

Breast cancer is one of the most common cancers diagnosed in adults, with 2.3 million new cases worldwide in 2020. Plants have been used in traditional medicine and are a potential source of pharmaceuticals. One example is the large Lamiaceae (mint) family. The Salvia genus, commonly known as the sages, is the largest genus in Lamiaceae with almost 900 known species. Different species of salvia are found in parts of the US, and some have a history in traditional medicine to treat cancers and other ailments. Preliminary research on three salvia species (S. lyrata, S. lyrata var. Purple …


Dysfunction Of Polyamine Metabolism In Down Syndrome Related To Cellular Senescence And Β-Amyloid Production, Andres D. Sola Nov 2024

Dysfunction Of Polyamine Metabolism In Down Syndrome Related To Cellular Senescence And Β-Amyloid Production, Andres D. Sola

Electronic Theses and Dissertations

Polyamines (PA) are ubiquitous in cells and highly involved in several important cellular functions and thus the dysregulation of their biosynthetic pathway is potentially associated with the progression of age-related diseases like Alzheimer’s’ disease (AD). Though there is research describing how PA content changes in organisms as they age or in those experiencing rapid aging from increased rates of senescence, as in Down syndrome (DS), it is not clear how this connection occurs and whether modulating this pathway may reveal downstream effects on related disease progression. This study examines how the modulation of the PA biosynthetic pathway by inhibition of …


Viral Genome Delivery Across Bacterial Cell Surfaces, Stephano M. Iglesias, Fenglin Li, Federica Briani, Gino Cingolani Nov 2024

Viral Genome Delivery Across Bacterial Cell Surfaces, Stephano M. Iglesias, Fenglin Li, Federica Briani, Gino Cingolani

Department of Biochemistry and Molecular Biology Faculty Papers

In 1952, Hershey and Chase used bacteriophage T2 genome delivery inside Escherichia coli to demonstrate that DNA, not protein, is the genetic material. Over 70 years later, our understanding of bacteriophage structure has grown dramatically, mainly thanks to the cryogenic electron microscopy revolution. In stark contrast, phage genome delivery in prokaryotes remains poorly understood, mainly due to the inherent challenge of studying such a transient and complex process. Here, we review the current literature on viral genome delivery across bacterial cell surfaces. We focus on icosahedral bacterial viruses that we arbitrarily sort into three groups based on the presence and …


The Effect Of Nerolidol On The Renal Dysfunction Following Bilateral Ureteral Obstruction In The Rat, Harun Rashed Toumi Nov 2024

The Effect Of Nerolidol On The Renal Dysfunction Following Bilateral Ureteral Obstruction In The Rat, Harun Rashed Toumi

Theses

This thesis addressed nerolidol’s potential therapeutic and protective effects on bilateral ureteral obstruction-induced uropathy in rats. Obstructive uropathy stands as a notable contributor to acute kidney injury (AKI), accounting for 5-10% of all AKI cases worldwide, with a particularly high prevalence among the elderly, constituting 22% of AKI cases in this age group. Urinary tract obstruction, often attributed to factors such as kidney stones, urinary tract deformities and benign/malignant growths such as benign prostatic hyperplasia (BPH) in older men can lead to detrimental outcomes if left untreated, potentially progressing to kidney failure and even mortality. The severity of the kidney …


Engineering The Coherent Phonon Transport In Polar Ferromagnetic Oxide Superlattices, In Hyeok Choi, Seung Gyo Jeong, Do-Gyeom Jeong, Ambrose Seo, Woo Seok Choi, Jong Seok Lee Nov 2024

Engineering The Coherent Phonon Transport In Polar Ferromagnetic Oxide Superlattices, In Hyeok Choi, Seung Gyo Jeong, Do-Gyeom Jeong, Ambrose Seo, Woo Seok Choi, Jong Seok Lee

Chemical and Materials Engineering Faculty Publications

Artificial superlattices composed of perovskite oxides serves as an essential platform for engineering coherent phonon transport by redefining the lattice periodicity, which strongly influences the lattice-coupled phase transitions in charge and spin degrees of freedom. However, previous methods of manipulating phonons have been limited to controlling the periodicity of superlattice, rather than utilizing complex mutual interactions that are prominent in transition metal oxides. In this study on oxide superlattices composed of ferromagnetic metallic SrRuO3 and quantum paraelectric SrTiO3 , phonon modulation by controlling the geometry of superlattice in atomic-scale precision is realized, demonstrating the coherent phonon engineering using structural and …


The Divergent Responses Of Salinity Generalists To Hyposaline Stress Provide Insights Into The Colonisation Of Freshwaters By Diatoms, Kathryn J. Judy, Eveline Pinseel, Kala M. Downey, Jeffrey A. Lewis, Andrew J. Alverson Nov 2024

The Divergent Responses Of Salinity Generalists To Hyposaline Stress Provide Insights Into The Colonisation Of Freshwaters By Diatoms, Kathryn J. Judy, Eveline Pinseel, Kala M. Downey, Jeffrey A. Lewis, Andrew J. Alverson

Biological Sciences Faculty Publications and Presentations

Environmental transitions, such as the salinity divide separating marine and fresh waters, shape biodiversity over both shallow and deep timescales, opening up new niches and creating opportunities for accelerated speciation and adaptive radiation. Understanding the genetics of environmental adaptation is central to understanding how organisms colonise and subsequently diversify in new habitats. We used time-resolved transcriptomics to contrast the hyposalinity stress responses of two diatoms. Skeletonema marinoi has deep marine ancestry but has recently invaded brackish waters. Cyclotella cryptica has deep freshwater ancestry and can withstand a much broader salinity range. Skeletonema marinoi is less adept at mitigating even mild …


Diverse Pathways In Gpcr-Mediated Activation Of Ca2+ Mobilization In Hek293 Cells, Francesco De Pascali, Asuka Inoue, Jeffrey L. Benovic Nov 2024

Diverse Pathways In Gpcr-Mediated Activation Of Ca2+ Mobilization In Hek293 Cells, Francesco De Pascali, Asuka Inoue, Jeffrey L. Benovic

Department of Biochemistry and Molecular Biology Faculty Papers

G protein-coupled receptors transduce extracellular stimuli into intracellular signaling. Ca2+ is a well-known second messenger that can be induced by G protein-coupled receptor activation through the primary canonical pathways involving Gαq- and Gβγ-mediated activation of phospholipase C-β (PLCβ). While some Gs-coupled receptors are shown to trigger Ca2+ mobilization, underlying mechanisms remain elusive. Here, we evaluated whether Gs-coupled receptors including the β2-adrenergic receptor (β2AR) and the prostaglandin EP2 and EP4 receptors (EP2R and EP4R) that are endogenously expressed in human embryonic kidney 293 …


Post-Transcriptional Methylation Of Mitochondrial-Trna Differentially Contributes To Mitochondrial Pathology, Sunita Maharjan, Howard Gamper, Yuka Yamaki, Thomas W. Christian, Robert Y. Henley, Nan-Sheng Li, Takeo Suzuki, Tsutomu Suzuki, Joseph A. Piccirilli, Meni Wanunu, Erin L. Seifert, Douglas C. Wallace, Ya-Ming Hou Oct 2024

Post-Transcriptional Methylation Of Mitochondrial-Trna Differentially Contributes To Mitochondrial Pathology, Sunita Maharjan, Howard Gamper, Yuka Yamaki, Thomas W. Christian, Robert Y. Henley, Nan-Sheng Li, Takeo Suzuki, Tsutomu Suzuki, Joseph A. Piccirilli, Meni Wanunu, Erin L. Seifert, Douglas C. Wallace, Ya-Ming Hou

Department of Biochemistry and Molecular Biology Faculty Papers

Human mitochondrial tRNAs (mt-tRNAs), critical for mitochondrial biogenesis, are frequently associated with pathogenic mutations. These mt-tRNAs have unusual sequence motifs and require post-transcriptional modifications to stabilize their fragile structures. However, whether a modification that stabilizes a wild-type (WT) mt-tRNA would also stabilize its pathogenic variants is unknown. Here we show that the N1-methylation of guanosine at position 9 (m1G9) of mt-Leu(UAA), while stabilizing the WT tRNA, has a destabilizing effect on variants associated with MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes). This differential effect is further demonstrated, as removal of the m1G9 …


Hepatic Targets To Control Blood Glucose And Potentially Aid In The Treatment Of Diabetes, Rena A. Velissarios Oct 2024

Hepatic Targets To Control Blood Glucose And Potentially Aid In The Treatment Of Diabetes, Rena A. Velissarios

PANDION: The Osprey Journal of Research and Ideas

Maintaining glucose homeostasis is extremely important to remain in good health and prevent disease. This homeostasis is achieved via the regulation of hepatic metabolic pathways like gluconeogenesis and glycogenesis by insulin, which is expressed during high blood glucose. Insulin is responsible for facilitating the uptake of glucose into other tissues from the blood, as well as signaling whether to stimulate or slow glucose metabolism in the liver. Hyperglycemia is one of the main effects of diabetes, a disease characterized by the body’s inability to produce or respond to insulin. Without insulin, hepatic glucose output continues and blood glucose accumulates, causing …


Cryo-Em Analysis Of Pseudomonas Phage Pa193 Structural Components, Stephano M. Iglesias, Chun-Feng Hou, Johnny Reid, Evan Schauer, Renae Geier, Angela Soriaga, Lucy Sim, Lucy Gao, Julian Whitelegge, Pierre Kyme, Deborah Birx, Sebastien Lemire, Gino Cingolani Oct 2024

Cryo-Em Analysis Of Pseudomonas Phage Pa193 Structural Components, Stephano M. Iglesias, Chun-Feng Hou, Johnny Reid, Evan Schauer, Renae Geier, Angela Soriaga, Lucy Sim, Lucy Gao, Julian Whitelegge, Pierre Kyme, Deborah Birx, Sebastien Lemire, Gino Cingolani

Department of Biochemistry and Molecular Biology Faculty Papers

The World Health Organization has designated Pseudomonas aeruginosa as a critical pathogen for the development of new antimicrobials. Bacterial viruses, or bacteriophages, have been used in various clinical settings, commonly called phage therapy, to address this growing public health crisis. Here, we describe a high-resolution structural atlas of a therapeutic, contractile-tailed Pseudomonas phage, Pa193. We used bioinformatics, proteomics, and cryogenic electron microscopy single particle analysis to identify, annotate, and build atomic models for 21 distinct structural polypeptide chains forming the icosahedral capsid, neck, contractile tail, and baseplate. We identified a putative scaffolding protein stabilizing the interior of the capsid 5-fold …


The Anaerobic Rose Chamber (Arc): Novel Applications For Probing Clostridioides Difficile Dynamics, Tatiana Zvonareva Oct 2024

The Anaerobic Rose Chamber (Arc): Novel Applications For Probing Clostridioides Difficile Dynamics, Tatiana Zvonareva

Chemistry & Biochemistry Theses & Dissertations

Clostridioides difficile infection (CDI) is an urgent public health threat with a high rate of recurrence and limited treatment options. Caused by the anaerobic intestinal pathogen C. difficile, this disease affects up to 500,000 Americans annually. Despite progress in our understanding of CDI pathophysiology, the lack of effective and accessible experimental platforms compatible with obligate anaerobe physiology hinders the advancement of treatment therapy. The application of in vivo models has been indispensable in understanding CDI pathophysiology, probing the complexity of the host response to the microbe, and establishing treatment protocols, and it continues to be essential in preclinical testing. …


Characterization Of Stealth Liposome-Based Nanoparticles Encapsulating Acat1/Soat1 Inhibitor F26: Potential Therapeutics For Niemann-Pick Type C And Other Neurodegenerative Diseases., Junghoon Lee Oct 2024

Characterization Of Stealth Liposome-Based Nanoparticles Encapsulating Acat1/Soat1 Inhibitor F26: Potential Therapeutics For Niemann-Pick Type C And Other Neurodegenerative Diseases., Junghoon Lee

Dartmouth College Ph.D Dissertations

Cholesterol dysregulation is implicated in neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson’s disease (PD), Huntington’s disease (HD) and Niemann-Pick type C disease (NPCD). This study focused on evaluating the potent ACAT1 inhibitor, F26, as a therapeutic strategy for NPCD. F26 demonstrated superior ACAT1 inhibition and efficacy compared to the previously studied inhibitor, F12511, both in vitro and in vivo. Notably, F26 exhibited enhanced pharmacokinetic properties, including prolonged duration of action and better brain retention, making it a more promising candidate for treating neurodegenerative diseases.

F26 was encapsulated in a liposome-based nanoparticle system, DSPE-PEG2000 with phosphatidylcholine (PC), for enhancing its …


Considerations For Widespread Implementation Of Blood-Based Biomarkers Of Alzheimer's Disease, Michelle Mielke, Matthew Anderson, Wesson Ashford, Andreas Jeromin, Pei-Jung Lin, Allyson Rosen, Jamie Tyrone, Lawren Vandevrede, Deanna Willis, Zul Merali Oct 2024

Considerations For Widespread Implementation Of Blood-Based Biomarkers Of Alzheimer's Disease, Michelle Mielke, Matthew Anderson, Wesson Ashford, Andreas Jeromin, Pei-Jung Lin, Allyson Rosen, Jamie Tyrone, Lawren Vandevrede, Deanna Willis, Zul Merali

Brain and Mind Institute

Diagnosing Alzheimer's disease (AD) poses significant challenges to health care, often resulting in delayed or inadequate patient care. The clinical integration of blood-based biomarkers (BBMs) for AD holds promise in enabling early detection of pathology and timely intervention. However, several critical considerations, such as the lack of consistent guidelines for assessing cognition, limited understanding of BBM test characteristics, insufficient evidence on BBM performance across diverse populations, and the ethical management of test results, must be addressed for widespread clinical implementation of BBMs in the United States. The Global CEO Initiative on Alzheimer's Disease BBM Workgroup convened to address these challenges …


Proteomic Analysis Reveals Major Proteins And Pathways That Mediate The Effect Of 17-Β-Estradiol In Cell Division And Apoptosis In Breast Cancer Mcf7 Cells, Zhenqi Zhou, Brihget Sicairos, Jianhong Zhou, Yuchun Du Oct 2024

Proteomic Analysis Reveals Major Proteins And Pathways That Mediate The Effect Of 17-Β-Estradiol In Cell Division And Apoptosis In Breast Cancer Mcf7 Cells, Zhenqi Zhou, Brihget Sicairos, Jianhong Zhou, Yuchun Du

Biological Sciences Faculty Publications and Presentations

Despite extensive research, the genes/proteins and pathways responsible for the physiological effects of estrogen remain elusive. In this study, we determined the effect of estrogen on global protein expression in breast cancer MCF7 cells using a proteomic method. The expression of 77 cytosolic, 74 nuclear, and 81 membrane/organelle proteins was significantly altered by 17-β-estradiol (E2). Protein enrichment analyses suggest that E2 may stimulate cell division primarily by promoting the G1 to S phase transition and advancing the G2/M checkpoint. The effect of E2 on cell survival was complex, as it could simultaneously enhance and inhibit apoptosis. Bioinformatics analysis suggests that …