Open Access. Powered by Scholars. Published by Universities.®

Biochemistry Commons

Open Access. Powered by Scholars. Published by Universities.®

Publications and Research

Series

Discipline
Keyword
Publication Year

Articles 1 - 29 of 29

Full-Text Articles in Biochemistry

Inhibiting Glutamine Utilization Creates A Synthetic Lethality For Suppression Of Atp Citrate Lyase In Kras-Driven Cancer Cells, Ahmet Hatipoglu, Deepak Menon, Talia Levy, Maria A. Frias, David A. Foster Oct 2022

Inhibiting Glutamine Utilization Creates A Synthetic Lethality For Suppression Of Atp Citrate Lyase In Kras-Driven Cancer Cells, Ahmet Hatipoglu, Deepak Menon, Talia Levy, Maria A. Frias, David A. Foster

Publications and Research

Metabolic reprogramming is now considered a hallmark of cancer cells. KRas-driven cancer cells use glutaminolysis to generate the tricarboxylic acid cycle intermediate α -ketoglutarate via a transamination reaction between glutamate and oxaloacetate. We reported previously that exogenously supplied unsaturated fatty acids could be used to synthesize phosphatidic acid–a lipid second messenger that activates both mammalian target of rapamycin (mTOR) complex 1 (mTORC1) and mTOR complex 2 (mTORC2). A key target of mTORC2 is Akt–a kinase that promotes survival and regulates cell metabolism. We report here that mono- unsaturated oleic acid stimulates the phosphoryla tion of ATP citrate lyase (ACLY) at …


Small Molecule Modulation Of Microbiota: A Systems Pharmacology Perspective, Qiao Liu, Bohyun Lee, Lei Xie Sep 2022

Small Molecule Modulation Of Microbiota: A Systems Pharmacology Perspective, Qiao Liu, Bohyun Lee, Lei Xie

Publications and Research

Background

Microbes are associated with many human diseases and influence drug efficacy. Small-molecule drugs may revolutionize biomedicine by fine-tuning the microbiota on the basis of individual patient microbiome signatures. However, emerging endeavors in small-molecule microbiome drug discovery continue to follow a conventional “one-drug-one-target-one-disease” process. A systematic pharmacology approach that would suppress multiple interacting pathogenic species in the microbiome, could offer an attractive alternative solution.

Results

We construct a disease-centric signed microbe–microbe interaction network using curated microbe metabolite information and their effects on host. We develop a Signed Random Walk with Restart algorithm for the accurate prediction of effect of microbes …


Ten Steps To Organize A Virtual Scientific Symposium And Engage Your Global Audience, Jiye Son, Jasmine Sabio, Ankit Jain, Rein V. Ulijn Jun 2022

Ten Steps To Organize A Virtual Scientific Symposium And Engage Your Global Audience, Jiye Son, Jasmine Sabio, Ankit Jain, Rein V. Ulijn

Publications and Research

The paper describes guidelines for the planning, organization, and successful execution of virtual, global scientific conferences for global audiences. The guidelines are based on experience and lessons learned during the organization of the 3-day 2020 Virtual Systems Chemistry Symposium hosted on Zoom webinar and Twitter, held on May 2020 with over 1000 registered participants from 46 different countries.


Eukaryotic Initiation Factor 4f Promotes A Reorientation Of Eukaryotic Initiation Factor 3 Binding On The 5 And The 3 Utrs Of Barley Yellow Dwarf Virus Mrna, Paul Powell, Usha Bhardwaj, Dixie Goss Apr 2022

Eukaryotic Initiation Factor 4f Promotes A Reorientation Of Eukaryotic Initiation Factor 3 Binding On The 5 And The 3 Utrs Of Barley Yellow Dwarf Virus Mrna, Paul Powell, Usha Bhardwaj, Dixie Goss

Publications and Research

Viral mRNAs that lack a 5 m 7 GTP cap and a 3 poly-A tail rely on structural elements in their untranslated regions (UTRs) to form unique RNA-protein complexes that regulate viral translation. Recent studies of the barley yellow dwarf virus (BYDV) have revealed eukaryotic initiation factor 3 (eIF3) plays a significant role in facilitating communication be- tween its 5 and 3 UTRs by binding both UTRs simultaneously. This report uses in vitro translation assays, fluorescence anisotropy binding assays, and selective 2 -hydroxyl acylation analyzed by primer ex-tension (SHAPE) footprinting to identify secondary structures that are selectively interacting with eIF3. …


Glycocalyx Mechanotransduction Mechanisms Are Involved In Renal Cancer Metastasis, Heriberto Moran, Limary M. Cancel, Peigen Huang, Sylvie Roberge, Tuoye Xu, John M. Tarbell, Lance L. Munn Jan 2022

Glycocalyx Mechanotransduction Mechanisms Are Involved In Renal Cancer Metastasis, Heriberto Moran, Limary M. Cancel, Peigen Huang, Sylvie Roberge, Tuoye Xu, John M. Tarbell, Lance L. Munn

Publications and Research

Mammalian cells, including cancer cells, are covered by a surface layer containing cell bound proteoglycans, glycoproteins, associated glycosaminoglycans and bound proteins that is commonly referred to as the glycocalyx. Solid tumors also have a dynamic fluid microenvironment with elevated interstitial flow. In the present work we further investigate the hypothesis that interstitial flow is sensed by the tumor glycocalyx leading to activation of cell motility and metastasis. Using a highly metastatic renal carcinoma cell line (SN12L1) and its low metastatic counterpart (SN12C) we demonstrate in vitro that the small molecule Suberoylanilide Hydroxamic Acid (SAHA) inhibits the heparan sulfate synthesis enzyme …


High-Resolution Cryo-Electron Microscopy Structure Of Photosystem Ii From The Mesophilic Cyanobacterium, Synechocystis Sp. Pcc 6803, Christopher J. Gisriel, Jimin Wang, Jinchan Liu, David A. Flesher, Krystle M. Reiss, Hao-Li Huang, Ke R. Yang, William H. Armstrong, M. R. Gunner, Victor S. Batista, Richard J. Debus, Gary W. Brudvig Dec 2021

High-Resolution Cryo-Electron Microscopy Structure Of Photosystem Ii From The Mesophilic Cyanobacterium, Synechocystis Sp. Pcc 6803, Christopher J. Gisriel, Jimin Wang, Jinchan Liu, David A. Flesher, Krystle M. Reiss, Hao-Li Huang, Ke R. Yang, William H. Armstrong, M. R. Gunner, Victor S. Batista, Richard J. Debus, Gary W. Brudvig

Publications and Research

Photosystem II (PSII) enables global-scale, light-driven water oxidation. Genetic manipulation of PSII from the mesophilic cyanobacterium Synechocystis sp. PCC 6803 has provided insights into the mechanism of water oxidation; however, the lack of a highresolution structure of oxygen-evolving PSII from this organism has limited the interpretation of biophysical data to models based on structures of thermophilic cyanobacterial PSII. Here, we report the cryo-electron microscopy structure of PSII from Synechocystis sp. PCC 6803 at 1.93-Å resolution. A number of differences are observed relative to thermophilic PSII structures, including the following: the extrinsic subunit PsbQ is maintained, the C terminus of the …


Cryptococcus Neoformans Melanization Incorporates Multiple Catecholamines To Produce Polytypic Melanin, Rosanna P. Baker, Christine Chrissian, Ruth E. Stark, Arturo Casadevall Dec 2021

Cryptococcus Neoformans Melanization Incorporates Multiple Catecholamines To Produce Polytypic Melanin, Rosanna P. Baker, Christine Chrissian, Ruth E. Stark, Arturo Casadevall

Publications and Research

Melanin is a major virulence factor in pathogenic fungi that enhances the ability of fungal cells to resist immune clearance. Cryptococcus neoformans is an important human pathogenic fungus that synthesizes melanin from exogenous tissue catecholamine precursors during infection, but the type of melanin made in cryptococcal meningoencephalitis is unknown. We analyzed the efficacy of various catecholamines found in brain tissue in supporting melanization using animal brain tissue and synthetic catecholamine mixtures reflecting brain tissue proportions. Solid-state NMR spectra of the melanin pigment produced from such mixtures yielded more melanin than expected if only the preferred constituent dopamine had been incorporated, …


Structure Of A Monomeric Photosystem Ii Core Complex From A Cyanobacterium Acclimated To Far-Red Light Reveals The Functions Of Chlorophylls D And F, Christopher J. Gisriel, Gaozhong Shen, Ming-Yang Ho, Vasily Kurashov, David A. Flesher, Jimin Wang, William H. Armstrong, John H. Golbeck, Marilyn R. Gunner, David J. Vinyard, Richard J. Debus, Gary W. Brudvig, Donald A. Bryant Nov 2021

Structure Of A Monomeric Photosystem Ii Core Complex From A Cyanobacterium Acclimated To Far-Red Light Reveals The Functions Of Chlorophylls D And F, Christopher J. Gisriel, Gaozhong Shen, Ming-Yang Ho, Vasily Kurashov, David A. Flesher, Jimin Wang, William H. Armstrong, John H. Golbeck, Marilyn R. Gunner, David J. Vinyard, Richard J. Debus, Gary W. Brudvig, Donald A. Bryant

Publications and Research

Far-red light (FRL) photoacclimation in cyanobacteria provides a selective growth advantage for some terrestrial cyanobacteria by expanding the range of photosynthetically active radiation to include far-red/near-infrared light (700–800 nm). During this photoacclimation process, photosystem II (PSII), the water:plastoquinone photooxidoreductase involved in oxygenic photosynthesis, is modified. The resulting FRL-PSII is comprised of FRL-specific core subunits and binds chlorophyll (Chl) d and Chl f molecules in place of several of the Chl a molecules found when cells are grown in visible light. These new Chls effectively lower the energy canonically thought to define the “red limit” for light required to drive photochemical …


A Conserved Structural Role For The Walker-A Lysine In P-Loop Containing Kinases, Fatlum Hajredini, Ranajeet Ghose Oct 2021

A Conserved Structural Role For The Walker-A Lysine In P-Loop Containing Kinases, Fatlum Hajredini, Ranajeet Ghose

Publications and Research

Bacterial tyrosine kinases (BY-kinases) and shikimate kinases (SKs) comprise two structurally divergent P-loop containing enzyme families that share similar catalytic site geometries, most notably with respect to their Walker-A, Walker-B, and DxD motifs. We had previously demonstrated that in BY-kinases, a specific interaction between the Walker-A and Walker-B motifs, driven by the conserved “catalytic” lysine housed on the former, leads to a conformation that is unable to efficiently coordinate Mg2+•ATP and is therefore incapable of chemistry. Here, using enhanced sampling molecular dynamics simulations, we demonstrate that structurally similar interactions between the Walker-A and Walker-B motifs, also mediated by …


Lighting The Way: Recent Insights Into The Structure And Regulation Of Phototropin Blue Light Receptors, Jaynee E. Hart, Kevin H. Gardner Mar 2021

Lighting The Way: Recent Insights Into The Structure And Regulation Of Phototropin Blue Light Receptors, Jaynee E. Hart, Kevin H. Gardner

Publications and Research

The phototropins (phots) are light-activated kinases that are critical for plant physiology and the many diverse optogenetic tools that they have inspired. Phototropins combine two bluelight- sensing Light–Oxygen–Voltage (LOV) domains (LOV1 and LOV2) and a C-terminal serine/threonine kinase domain, using the LOV domains to control the catalytic activity of the kinase. While much is known about the structure and photochemistry of the light-perceiving LOV domains, particularly in how activation of the LOV2 domain triggers the unfolding of alpha helices that communicate the light signal to the kinase domain, many questions about phot structure and mechanism remain. Recent studies have made …


Unconventional Constituents And Shared Molecular Architecture Of The Melanized Cell Wall Of C. Neoformans And Spore Wall Of S. Cerevisiae, Christine Chrissian, Coney Pei-Chin Lin, Emma Camacho, Arturo Casadevall, Aaron M. Neiman, Ruth E. Stark Dec 2020

Unconventional Constituents And Shared Molecular Architecture Of The Melanized Cell Wall Of C. Neoformans And Spore Wall Of S. Cerevisiae, Christine Chrissian, Coney Pei-Chin Lin, Emma Camacho, Arturo Casadevall, Aaron M. Neiman, Ruth E. Stark

Publications and Research

The fungal cell wall serves as the interface between the cell and the environment. Fungal cell walls are composed largely of polysaccharides, primarily glucans and chitin, though in many fungi stress-resistant cell types elaborate additional cell wall structures. Here, we use solid-state nuclear magnetic resonance spectroscopy to compare the architecture of cell wall fractions isolated from Saccharomyces cerevisiae spores and Cryptococcus neoformans melanized cells. The specialized cell walls of these two divergent fungi are highly similar in composition. Both use chitosan, the deacetylated derivative of chitin, as a scaffold on which a polyaromatic polymer, dityrosine and melanin, respectively, is assembled. …


Retrieving Functional Pathways Of Biomolecules From Single-Particle Snapshots, Ali Dashti, Ghoncheh Mashayekhi, Mrinal Shekhar, Danya Ben Hail, Salah Salah, Peter Schwander, Amedee Des Georges, Abhishek Singharoy, Joachim Frank, Abbas Ourmazd Sep 2020

Retrieving Functional Pathways Of Biomolecules From Single-Particle Snapshots, Ali Dashti, Ghoncheh Mashayekhi, Mrinal Shekhar, Danya Ben Hail, Salah Salah, Peter Schwander, Amedee Des Georges, Abhishek Singharoy, Joachim Frank, Abbas Ourmazd

Publications and Research

A primary reason for the intense interest in structural biology is the fact that knowledge of structure can elucidate macromolecular functions in living organisms. Sustained effort has resulted in an impressive arsenal of tools for determining the static structures. But under physiological conditions, macromolecules undergo continuous conformational changes, a subset of which are functionally important. Techniques for capturing the continuous conformational changes underlying function are essential for further progress. Here, we present chemically-detailed conformational movies of biological function, extracted data-analytically from experimental single-particle cryo-electron microscopy (cryo-EM) snapshots of ryanodine receptor type 1 (RyR1), a calcium-activated calcium channel engaged in the …


A Review Of Small Molecule Inhibitors And Functional Probes Of Human Cathepsin L, Dibyendu Dana, Sanjai Kumar Jan 2020

A Review Of Small Molecule Inhibitors And Functional Probes Of Human Cathepsin L, Dibyendu Dana, Sanjai Kumar

Publications and Research

Human cathepsin L belongs to the cathepsin family of proteolytic enzymes with primarily an endopeptidase activity. Although its primary functions were originally thought to be only of a housekeeping enzyme that degraded intracellular and endocytosed proteins in lysosome, numerous recent studies suggest that it plays many critical and specific roles in diverse cellular settings. Not surprisingly, the dysregulated function of cathepsin L has manifested itself in several human diseases, making it an attractive target for drug development. Unfortunately, several redundant and isoform-specific functions have recently emerged, adding complexities to the drug discovery process. To address this, a series of chemical …


A Kinesin Adapter Directly Mediates Dendritic Mrna Localization During Neural Development In Mice, Hao Wu, Jing Zhou, Tianhui Zhu, Ivan Cohen, Jason Dictenberg Jan 2020

A Kinesin Adapter Directly Mediates Dendritic Mrna Localization During Neural Development In Mice, Hao Wu, Jing Zhou, Tianhui Zhu, Ivan Cohen, Jason Dictenberg

Publications and Research

Motor protein-based active transport is essential for mRNA localization and local translation in animal cells, yet how mRNA granules interact with motor proteins remains poorly understood. Using an unbiased yeast two–hybrid screen for interactions between murine RNA-binding proteins (RBPs) and motor proteins, here we identified protein interaction with APP tail-1 (PAT1) as a potential direct adapter between zipcode-binding protein 1 (ZBP1, a β-actin RBP) and the kinesin-I motor complex. The amino acid sequence of mouse PAT1 is similar to that of the kinesin light chain (KLC), and we found that PAT1 binds to KLC directly. Studying PAT1 in mouse …


Inclusion Of Enclosed Hydration Effects In The Binding Free Energy Estimation Of Dopamine D3 Receptor Complexes, Rajat Kumar Pal, Satishkumar Gadhiya, Steven Ramsey, Pierpaolo Cordone, Lauren Wickstrom, Wayne W. Harding, Tom Kurtzman, Emilio Gallicchio Sep 2019

Inclusion Of Enclosed Hydration Effects In The Binding Free Energy Estimation Of Dopamine D3 Receptor Complexes, Rajat Kumar Pal, Satishkumar Gadhiya, Steven Ramsey, Pierpaolo Cordone, Lauren Wickstrom, Wayne W. Harding, Tom Kurtzman, Emilio Gallicchio

Publications and Research

Confined hydration and conformational flexibility are some of the challenges encountered for the rational design of selective antagonists of G-protein coupled receptors.We present a set of C3-substituted (-) -stepholidine derivatives as potent binders of the dopamine D3 receptor.The compounds are characterized biochemically, as well as by computer modeling using a novel molecular dynamics-based alchemical binding free energy approach which incorporates the effect of the displacement of enclosed water molecules from the binding site.The free energy of displacement of specific hydration sites is obtained using the Hydration Site Analysis method with explicit solvation. This work underscores the critical role of confined …


Bright Green Biofluorescence In Sharks Derives From Bromo-Kynurenine Metabolism, Hyun Bong Park, Yick Chong Lam, Jean P. Gaffney, James C. Weaver, Sara Rose Krivoshik, Randy Hamchand, Vincent Pieribone, David F. Gruber, Jason M. Crawford Sep 2019

Bright Green Biofluorescence In Sharks Derives From Bromo-Kynurenine Metabolism, Hyun Bong Park, Yick Chong Lam, Jean P. Gaffney, James C. Weaver, Sara Rose Krivoshik, Randy Hamchand, Vincent Pieribone, David F. Gruber, Jason M. Crawford

Publications and Research

Although in recent years there has been an increased awareness of the widespread nature of biofluorescence in the marine environment, the diversity of the molecules responsible for this luminescent phenotype has been mostly limited to green fluorescent proteins (GFPs), GFP-like proteins, and fluorescent fatty acid-binding proteins (FABPs). In the present study, we describe a previously undescribed group of brominated tryptophan-kynurenine small molecule metabolites responsible for the green biofluorescence in two species of sharks and provide their structural, antimicrobial, and spectral characterization. Multi-scale fluorescence microscopy studies guided the discovery of metabolites that were differentially produced in fluorescent versus non-fluorescent skin, as …


Synthesis And Evaluations Of “1,4-Triazolyl Combretacoumarins” And Desmethoxy Analogs, Tashrique A. Khandaker, Jessica D. Hess, Renato Aguilera, Graciela Andrei, Robert Snoeck, Dominique Schols, Padmanava Pradhan, Mahesh K. Lakshman Aug 2019

Synthesis And Evaluations Of “1,4-Triazolyl Combretacoumarins” And Desmethoxy Analogs, Tashrique A. Khandaker, Jessica D. Hess, Renato Aguilera, Graciela Andrei, Robert Snoeck, Dominique Schols, Padmanava Pradhan, Mahesh K. Lakshman

Publications and Research

1,4-Triazolyl combretacoumarins have been prepared by linking the trimethoxyarene unit of combretastatin A4 with coumarins, via a 1,2,3-triazole. For this, 4-azidocoumarins were accessed by a sequential two-step, one-pot reaction of 4-hydroxycoumarins with (benzotriazol-1-yloxy)tris(dimethylamino)phosphonium hexafluorophosphate (BOP), followed by reaction with NaN3. In the reaction with BOP, a coumarin-derived phosphonium ion intermediate seems to form, leading to an O4-(benzotriazolyl)coumarin derivative. For the CuAAC reaction of azidocoumarins with 5-ethynyl-1,2,3-trimethoxybenzene, catalytic [(MeCN)4Cu]PF6 in CH2Cl2/MeOH with 2,6-lutidine, at 50 oC, was suitable. The 4-azidocoumarins were less reactive as compared to PhN3 and …


Reduced Alphabet Of Prebiotic Amino Acids Optimally Encodes The Conformational Space Of Diverse Extant Protein Folds, Armando D. Solis Jul 2019

Reduced Alphabet Of Prebiotic Amino Acids Optimally Encodes The Conformational Space Of Diverse Extant Protein Folds, Armando D. Solis

Publications and Research

Background

There is wide agreement that only a subset of the twenty standard amino acids existed prebiotically in sufficient concentrations to form functional polypeptides. We ask how this subset, postulated as {A,D,E,G,I,L,P,S,T,V}, could have formed structures stable enough to found metabolic pathways. Inspired by alphabet reduction experiments, we undertook a computational analysis to measure the structural coding behavior of sequences simplified by reduced alphabets. We sought to discern characteristics of the prebiotic set that would endow it with unique properties relevant to structure, stability, and folding.

Results

Drawing on a large dataset of single-domain proteins, we employed an information-theoretic measure …


Global Biochemical And Structural Analysis Of The Type Iv Pilus From The Gram-Positive Bacterium Streptococcus Sanguinis, Jamie-Lee Berry, Ishwori Gurung, Jan Haug Anonsen, Ingrid Spielman, Elliot Harper, Alexander M. J. Hall, Vivianne J. Goosens, Claire Raynaud, Michael Koomey, Nicolas Biais, Steve Matthews, Vladimir Pelicic Mar 2019

Global Biochemical And Structural Analysis Of The Type Iv Pilus From The Gram-Positive Bacterium Streptococcus Sanguinis, Jamie-Lee Berry, Ishwori Gurung, Jan Haug Anonsen, Ingrid Spielman, Elliot Harper, Alexander M. J. Hall, Vivianne J. Goosens, Claire Raynaud, Michael Koomey, Nicolas Biais, Steve Matthews, Vladimir Pelicic

Publications and Research

Type IV pili (Tfp) are functionally versatile filaments, widespread in prokaryotes, that belong to a large class of filamentous nanomachines known as type IV filaments (Tff). Although Tfp have been extensively studied in several Gram-negative pathogens where they function as key virulence factors, many aspects of their biology remain poorly understood. Here, we performed a global biochemical and structural analysis of Tfp in a recently emerged Gram-positive model, Streptococcus sanguinis. In particular, we focused on the five pilins and pilin-like proteins involved in Tfp biology in S. sanguinis. We found that the two major pilins, PilE1 and PilE2, (i) follow …


Deletion Of Mgr2p Affects The Gating Behavior Of The Tim23 Complex, Oygul Mirzalieva, Shinhye Jeon, Kevin Damri, Ruth Hartke, Layla Drwesh, Keren Demishtein-Zohary, Abdussalam Azem, Cory D. Dunn, Pablo M. Peixoto Jan 2019

Deletion Of Mgr2p Affects The Gating Behavior Of The Tim23 Complex, Oygul Mirzalieva, Shinhye Jeon, Kevin Damri, Ruth Hartke, Layla Drwesh, Keren Demishtein-Zohary, Abdussalam Azem, Cory D. Dunn, Pablo M. Peixoto

Publications and Research

The TIM23 complex is a hub for translocation of preproteins into or across the mitochondrial inner membrane. This dual sorting mechanism is currently being investigated, and in yeast appears to be regulated by a recently discovered subunit, the Mgr2 protein. Deletion of Mgr2p has been found to delay protein translocation into the matrix and accumulation in the inner membrane. This result and other findings suggested that Mgr2p controls the lateral release of inner membrane proteins harboring a stop-transfer signal that follows an N-terminal amino acid signal. However, the mechanism of lateral release is unknown. Here, we used patch clamp electrophysiology …


Optimizing Spacer Length For Positioning Functional Groups In Bio-Waste, Revathi Iyengar, Maria Faure-Betancourt, Saleh Talukdar, Jinting Ye, Abel E. Navarro Sep 2018

Optimizing Spacer Length For Positioning Functional Groups In Bio-Waste, Revathi Iyengar, Maria Faure-Betancourt, Saleh Talukdar, Jinting Ye, Abel E. Navarro

Publications and Research

The goal of this study was to determine the optimal chain length needed for tethering functional groups on bio-wastes. The purpose of modifying the surface of bio-waste is to improve their affinity for phenols. To this end, four different aminated green tea leaves, with the amine group located at the end of 6, 8, 10, and 12 carbons were synthesized. Green approaches to functionalization lead to fewer reactive sites. Optimizing spacer length is one way to ameliorate this. The aminated tea leaves were prepared by a tosylation reaction followed by displacement with a diamine used in excess. The tea leaves …


Cloning And Spatiotemporal Expression Of Xenopus Laevis Apolipoprotein Ci, Jyotsna Sridharan, Tomomi Haremaki, Daniel C. Weinstein Jan 2018

Cloning And Spatiotemporal Expression Of Xenopus Laevis Apolipoprotein Ci, Jyotsna Sridharan, Tomomi Haremaki, Daniel C. Weinstein

Publications and Research

Apolipoprotein CI (ApoCI) belongs to the Apolipoprotein superfamily, members of which are involved in lipid transport, uptake and homeostasis. Excessive ApoCI has been implicated in atherosclerosis and Alzheimer’s disease in humans. In this study we report the isolation of Xenopus laevis apoCI and describe the expression pattern of this gene during early development, using reverse transcription polymerase chain reaction and whole mount in situ hybridization. Xenopus apoCI is enriched in the dorsal ectoderm during gastrulation, and is subsequently expressed in sensory placodes, neural tube and cranial neural crest. These data suggest as yet uncharacterized roles for ApoCI during early vertebrate …


Thermodynamic And Kinetic Analyses Of Iron Response Element (Ire)-Mrna Binding To Iron Regulatory Protein, Irp1, Mateen A. Khan, William E. Walden, Elizabeth C. Theil, Dixie J. Goss Aug 2017

Thermodynamic And Kinetic Analyses Of Iron Response Element (Ire)-Mrna Binding To Iron Regulatory Protein, Irp1, Mateen A. Khan, William E. Walden, Elizabeth C. Theil, Dixie J. Goss

Publications and Research

Comparison of kinetic and thermodynamic properties of IRP1 (iron regulatory protein1) binding to FRT (ferritin) and ACO2 (aconitase2) IRE-RNAs, with or without Mn2+, revealed differences specific to each IRE-RNA. Conserved among animal mRNAs, IRE-RNA structures are noncoding and bind Fe2+ to regulate biosynthesis rates of the encoded, iron homeostatic proteins. IRP1 protein binds IRERNA, inhibiting mRNA activity; Fe2+ decreases IRE-mRNA/IRP1 binding, increasing encoded protein synthesis. Here, we observed heat, 5 °C to 30 °C, increased IRP1 binding to IRE-RNA 4-fold (FRT IRE-RNA) or 3-fold (ACO2 IRE-RNA), which was enthalpy driven and entropy favorable. Mn2+ (50 μM, 25 °C) increased IRE-RNA/IRP1 …


Estrogen-Activated Mdm2 Disrupts Mammary Tissue Architecture Through A P53-Independent Pathway, Nandini Kundu, Angelika Brekman, Jun Yeob Kim, Gu Xiano, Chong Gao, Jill Bargonetti May 2017

Estrogen-Activated Mdm2 Disrupts Mammary Tissue Architecture Through A P53-Independent Pathway, Nandini Kundu, Angelika Brekman, Jun Yeob Kim, Gu Xiano, Chong Gao, Jill Bargonetti

Publications and Research

The Cancer Genome Atlas (TCGA) data indicate that high MDM2 expression correlates with all subtypes of breast cancer. Overexpression of MDM2 drives breast oncogenesis in the presence of wild-type or mutant p53 (mtp53). Importantly, estrogen-receptor positive (ER+) breast cancers overexpress MDM2 and estrogen mediates this expression. We previously demonstrated that this estrogen-MDM2 axis activates the proliferation of breast cancer cell lines T47D (mtp53 L194F) and MCF7 (wild-type p53) in a manner independent of increased degradation of wildtype p53 (ie, p53-independently). Herein we present data supporting the role of the estrogen-MDM2 axis in regulating cell proliferation and mammary tissue architecture of …


Effects Of Water Availability And Pest Pressures On Tea (Camellia Sinensis) Growth And Functional Quality, Selena Ahmed, Colin M. Orians, Timothy S. Griffin, Sarabeth Buckley, Uchenna Unachukwu, Anne Elise Stratton, John Richard Stepp, Albert Robbat Jr, Sean Cash, Edward J. Kennelly Dec 2013

Effects Of Water Availability And Pest Pressures On Tea (Camellia Sinensis) Growth And Functional Quality, Selena Ahmed, Colin M. Orians, Timothy S. Griffin, Sarabeth Buckley, Uchenna Unachukwu, Anne Elise Stratton, John Richard Stepp, Albert Robbat Jr, Sean Cash, Edward J. Kennelly

Publications and Research

Extreme shifts in water availability linked to global climate change are impacting crops worldwide. The present study examines the direct and interactive effects of water availability and pest pressures on tea (Camellia sinensis; Theaceae) growth and functional quality. Manipulative greenhouse experiments were used to measure the effects of variable water availability and pest pressures simulated by jasmonic acid (JA) on tea leaf growth and secondary metabolites that determine tea quality. Water treatments were simulated to replicate ideal tea growing conditions and extreme precipitation events in tropical southwestern China, a major centre of tea production. Results show that higher water availability …


Β2 Adrenergic Receptor Fluorescent Protein Fusions Traffic To The Plasma Membrane And Retain Functionality, Jaclyn Bubnell, Patrick Pfister, Maria L. Sapar, Matthew E. Rogers, Paul Feinstein Sep 2013

Β2 Adrenergic Receptor Fluorescent Protein Fusions Traffic To The Plasma Membrane And Retain Functionality, Jaclyn Bubnell, Patrick Pfister, Maria L. Sapar, Matthew E. Rogers, Paul Feinstein

Publications and Research

Green fluorescent protein (GFP) has proven useful for the study of protein interactions and dynamics for the last twenty years. A variety of new fluorescent proteins have been developed that expand the use of available excitation spectra. We have undertaken an analysis of seven of the most useful fluorescent proteins (XFPs), Cerulean (and mCerulean3), Teal, GFP, Venus, mCherry and TagRFP657, as fusions to the archetypal G-protein coupled receptor, the β2 adrenergic receptor (β2AR). We have characterized these β2AR::XFP fusions in respect to membrane trafficking and G-protein activation. We noticed that in the mouse neural cell line, OP 6, that membrane …


The Terebridae And Teretoxins: Combining Phylogeny And Anatomy For Concerted Discovery Of Bioactive Compounds, Nicolas Puillandre, Mandë Holford Sep 2010

The Terebridae And Teretoxins: Combining Phylogeny And Anatomy For Concerted Discovery Of Bioactive Compounds, Nicolas Puillandre, Mandë Holford

Publications and Research

The Conoidea superfamily, comprised of cone snails, terebrids, and turrids, is an exceptionally promising group for the discovery of natural peptide toxins. The potential of conoidean toxins has been realized with the distribution of the first Conus (cone snail) drug, Prialt (ziconotide), an analgesic used to alleviate chronic pain in HIV and cancer patients. Cone snail toxins (conotoxins) are highly variable, a consequence of a high mutation rate associated to duplication events and positive selection. As Conus and terebrids diverged in the early Paleocene, the toxins from terebrids (teretoxins) may demonstrate highly divergent and unique functionalities. Recent analyses of the …


Dynamics On Multiple Timescales In The Rna-Directed Rna Polymerase From The Cystovirus Φ6, Zhen Ren, Hsin Wang, Ranajeet Ghose Apr 2010

Dynamics On Multiple Timescales In The Rna-Directed Rna Polymerase From The Cystovirus Φ6, Zhen Ren, Hsin Wang, Ranajeet Ghose

Publications and Research

The de novoinitiating RNA-directed RNA polymerase (RdRP), P2, forms the central machinery in the infection cycle of the bacteriophage ϕ6 by performing the dual tasks of replication and transcription of the double-stranded RNA genome in the host cell. By measurement and quantitative analysis of multiple-quantum spin-relaxation data for the δ1 positions of Ile residues that are distributed over the 3D-fold of P2, we find that the enzyme is dynamic both on the fast (ps–ns) and slow (µs–ms) timescales. The characteristics of several motional modes including those that coincide with the catalytic timescale (500–800/s) are altered in the presence of …


Morphological Changes And Immunohistochemical Expression Of Rage And Its Ligands In The Sciatic Nerve Of Hyperglycemic Pig (Sus Scrofa), Judyta K. Juranek, Alexey Aleshin, Eileen M. Rattigan, Lynne Johnson, Wu Qu, Fei Song, Radha Ananthakrishnan, Nosirudeen Quadri, Shi Du Yan, Ravichandran Ramasamy, Ann Marie Schmidt, Matthew S. Geddis Jan 2010

Morphological Changes And Immunohistochemical Expression Of Rage And Its Ligands In The Sciatic Nerve Of Hyperglycemic Pig (Sus Scrofa), Judyta K. Juranek, Alexey Aleshin, Eileen M. Rattigan, Lynne Johnson, Wu Qu, Fei Song, Radha Ananthakrishnan, Nosirudeen Quadri, Shi Du Yan, Ravichandran Ramasamy, Ann Marie Schmidt, Matthew S. Geddis

Publications and Research

The aim of our project was to study the effect of streptozotocin (STZ)—induced hyperglycemia on sciatic nerve morphology, blood plasma markers and immunohistochemical expression of RAGE (the Receptor for Advanced Glycation End-products), and its ligands—S100B and Carboxymethyl Lysine (CML)-advanced glycation endproduct (AGE) in the laboratory pig. Six months after STZ—injections, blood plasma measurements, morphometric analysis of sciatic nerve fiber density, immunofluorescent distribution of potential molecular neuropathy contributors, ELISA measurement of plasma AGE level and HPLC analysis of sciatic nerve levels of one of the pre-AGE and the glycolysis intermediate products—methyl-glyoxal (MG) were performed. The results of our study revealed that …