Life Sciences Commons^™

Amylin Structure, Aggregation, And Pancreatic Β Cell Toxicity, Sharadrao Patil

MCB Articles

In most type 2 diabetes patients, amyloid plaques have been found juxtaposed with membranes of pancreatic β-cells. These plaques are composed of amyloid fibrils of the 37 residue endocrine hormone amylin and cause distinct changes in cell membrane morphology associated with the destruction of β-cells. Research is still ongoing to identify the toxic species involved and the mechanisms by which mature fibrils or oligomers cause cytotoxicity. The projects undertaken were designed to study the molecular structural features of amylin, mechanism of amyloid aggregation and, to develop cytotoxicity inhibitors. We determined the structure of human amylin bound to SDS micelles using …

Real-Time Kinetic Studies Of Bacillus Subtilis Oxalate Decarboxylase And Ceriporiopsis Subvermispora Oxalate Oxidase Using Luminescent Oxygen Sensor, Laura Molina, Thomas Goodall, Umar Twahir, Ellen W. Moomaw

Faculty and Research Publications

Oxalate decarboxylase (OxDC), an enzyme of the bicupin superfamily, catalyzes the decomposition of oxalate into carbon dioxide and formate at an optimal pH of 4.3 in the presence of oxygen. However, about 0.2% of all reactions occur through an oxidase mechanism that consumes oxygen while producing two equivalents of carbon dioxide and one equivalent of hydrogen peroxide. The kinetics of oxidase activity were studied by measuring the consumption of dissolved oxygen over time using a luminescent oxygen sensor. We describe the implementation of and improvements to the oxygen consumption assay. The oxidase activity of wild type OxDC was compared to …

Mtorc2 Is Required For Rit-Mediated Oxidative Stress Resistance, Weikang Cai, Douglas A. Andres

Molecular and Cellular Biochemistry Faculty Publications

Rit, a member of the Ras family of GTPases, has been shown to promote cell survival in response to oxidative stress, in part by directing an evolutionarily conserved p38 MAPK-Akt survival cascade. Aberrant Rit signaling has recently been implicated as a driver mutation in human cancer, adding importance to the characterization of critical Rit effector pathways. However, the mechanism by which Rit-p38 signaling regulated Akt activity was unknown. Here, we identify mTORC2 as a critical downstream mediator of Rit-dependent survival signaling in response to reactive oxygen species (ROS) stress. Rit interacts with Sin1 (MAPKAP1), and Rit loss compromises ROS-dependent mTORC2 …

Investigating The Links Between Ozone And Organic Aerosol Chemistry In A Biomass Burning Plume From A Prescribed Fire In California Chaparral, M. J. Alvarado, C. R. Lonsdale, Robert Yokelson, S. K. Akagi, H. Coe, J. S. Craven, E. V. Fischer, G. R. Mcmeeking, J. H. Seinfeld, T. Soni, J. W. Taylor, D. R. Weise, C. E. Wold

Chemistry and Biochemistry Faculty Publications

Within minutes after emission, rapid, complex photochemistry within a biomass burning smoke plume can cause large changes in the concentrations of ozone (O₃) and organic aerosol (OA). Being able to understand and simulate this rapid chemical evolution under a wide variety of conditions is a critical part of forecasting the impact of these fires on air quality, atmospheric composition, and climate. Here we use version 2.1 of the Aerosol Simulation Program (ASP) to simulate the evolution of O₃ and secondary organic aerosol (SOA) within a young biomass burning smoke plume from the Williams prescribed burn in chaparral, …

Fap206 Is A Microtubule-Docking Adapter For Ciliary Radial Spoke 2 And Dynein C, Krishna K. Vasudevan, Kangkang Song, Lea M. Alford, Winfield Sale, Erin E. Dymek, Elizabeth F. Smith, Todd Hennessey, Ewa Joachimiak, Paulina Urbanska, Dorota Wloga, William Dentler, Daniela Nicastro, Jacek Gaertig

Dartmouth Scholarship

Radial spokes are conserved macromolecular complexes that are essential for ciliary motility. A triplet of three radial spokes, RS1, RS2, and RS3, repeats every 96 nm along the doublet microtubules. Each spoke has a distinct base that docks to the doublet and is linked to different inner dynein arms. Little is known about the assembly and functions of individual radial spokes. A knockout of the conserved ciliary protein FAP206 in the ciliate Tetrahymena resulted in slow cell motility. Cryo–electron tomography showed that in the absence of FAP206, the 96-nm repeats lacked RS2 and dynein c. Occasionally, RS2 assembled but lacked …

A Microrna-1280/Jag2 Network Comprises A Novel Biological Target In High-Risk Medulloblastoma, Fengfei Wang, Marc Remke, Tze-Chen Hsieh, Lizi Wu, Cynthia Hawkins, Joseph M. Wu, Erxi Wu

NYMC Faculty Publications

Over-expression of PDGF receptors (PDGFRs) has been previously implicated in high-risk medulloblastoma (MB) pathogenesis. However, the exact biological functions of PDGFRα and PDGFRβ signaling in MB biology remain poorly understood. Here, we report the subgroup specific expression of PDGFRα and PDGFRβ and their associated biological pathways in MB tumors. c-MYC, a downstream target of PDGFRβ but not PDGFRα, is involved in PDGFRβ signaling associated with cell proliferation, cell death, and invasion. Concurrent inhibition of PDGFRβ and c-MYC blocks MB cell proliferation and migration synergistically. Integrated analysis of miRNA and miRNA targets regulated by both PDGFRβ and c-MYC reveals that increased …

Regulation Of Phialide Morphogenesis In Aspergillus Nidulans, Hu Yin

School of Biological Sciences: Dissertations, Theses, and Student Research

Filamentous fungi have two distinctive life cycles, vegetative growth and development for sexual or asexual spore formation. The asexual reproduction in development as conidiation in A. nidulans is the dominant form of producing spores effectively. A complex conidiophore structure is developed during asexual reproduction process. The conidiophore is formed from hyphal cell and consists of stalk, vesicle, metulae, phialide and conidial spores. Phialides are essential sporogenous cells in the conidiophore structure. The growth pattern is switched from acropetal to basipetal between phialide and spores, which makes phialide a unique cell type in A. nidulans and other phialide producing fungi. Study …

Synthesis And Characterization Of Polymer (Sulfonated Poly-Ether-Ether-Ketone) Based Nanocomposite (H-Boron Nitride) Membrane For Hydrogen Storage, Naresh Muthu, S. Rajashabala, R. Kannan

Chemistry and Biochemistry Faculty Publications

The development of light weight and compact hydrogen storage materials is still prerequisite to fuel-cell technology to be fully competitive. The present experimental study reports the hydrogen storage capability of sulfonated poly-ether-ether-ketone (SPEEK)-hexagonal boron nitride (h-BN) (SPEEK-h-BN) nanocomposite membranes. The nanocomposite membranes are prepared by considering various amount of h-BN (0, 1, 3 and 5 wt. %) by phase inversion technique. The degree of sulfonation of the PEEK (SPEEK) is found to be 65% by Proton Nuclear Magnetic Resonance (¹H NMR) spectroscopy. Hydrogen adsorption studies have been carried out using a Seiverts-like hydrogenation setup. The membranes are characterized …

Loss Of Thiol Repair Systems In Human Cataractous Lenses, Min Wei, Kui-Yi Xing, Yin-Chuan Fan, Teodosio Libondi, Marjorie F. Lou

School of Veterinary and Biomedical Sciences: Faculty Publications

PURPOSE. The purpose of this study was to investigate the thiol repair systems of thioltransferase (TTase) and thioredoxin (Trx) and oxidation-damaged proteins in human cataractous lenses.

METHODS. Cataractous lenses in humans (57–85 years of age) were classified into cortical, nuclear, mixed, mature, and hypermature cataract types by using a lens opacity classification system, and were obtained by extracapsular cataract extraction (ECCE) procedure. Cortical and nuclear cataracts were grouped by decreasing order of visual acuity into optical chart reading (R), counting fingers (CF), hand motion (HM), and light perception (LP). ECCE lens homogenate was analyzed for glutathione (GSH) level and enzyme …

Effect Of Hydrogen Peroxide On The Biosynthesis Of Heme And Proteins: Potential Implications For The Partitioning Of Glu-TrnaGlu Between These Pathways, Carolina Farah, Gloria Levicán, Michael Ibba, Omar Orellana

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Glutamyl-tRNA (Glu-tRNA^Glu) is the common substrate for both protein translation and heme biosynthesis via the C5 pathway. Under normal conditions, an adequate supply of this aminoacyl-tRNA is available to both pathways. However, under certain circumstances, Glu-tRNA^Glu can become scarce, resulting in competition between the two pathways for this aminoacyl-tRNA. In Acidithiobacillus ferrooxidans, glutamyl-tRNA synthetase 1 (GluRS1) is the main enzyme that synthesizes Glu-tRNA^Glu. Previous studies have shown that GluRS1 is inactivated in vitro by hydrogen peroxide (H₂O₂). This raises the question as to whether H₂O₂ negatively affects …

Dancing Through Life: Allosteric Transitions And Structural Analysis Of Hsp70 And Hsp110 Chaperone Proteins, Gabrielle Stetz, Gennady M. Verkhivker

Student Scholar Symposium Abstracts and Posters

The molecular chaperone protein Hsp70 is centrally involved in cellular homeostasis by assisting in the folding and degradation of protein substrates. Hsp70 is joined by co-chaperones, such as Hsp110, which contribute to specialized tasks of the Hsp70 complex. Imbalances of this heat shock protein system are believed to be involved with the deregulation of cancer pathways and other human diseases. Better understanding of how these heat shock proteins work at the molecular level, which has been investigated using molecular docking tools, will give more clues about biological function. Simulating the formation and function of Hsp70 based chaperone complexes could provide …

Design, Assessment, And In Vivo Evaluation Of A Computational Model Illustrating The Role Of Cav1 In Cd4+ T-Lymphocytes, Brittany D. Conroy, Tyler A. Herek, Timonthy D. Shew, Matthew Latner, Joshua J. Larson, Laura Allen, Paul H. Davis, Tomáš Helikar, Christine E. Cutucache

Department of Biochemistry: Faculty Publications

Caveolin-1 (CAV1) is a vital scaffold protein heterogeneously expressed in both healthy and malignant tissue. We focus on the role of CAV1 when overexpressed in T-cell leukemia. Previously, we have shown that CAV1 is involved in cell-to-cell communication, cellular proliferation, and immune synapse formation; however, the molecular mechanisms have not been elucidated.We hypothesize that the role of CAV1 in immune synapse formation contributes to immune regulation during leukemic progression, thereby warranting studies of the role of CAV1 in CD4⁺ T-cells in relation to antigen-presenting cells. To address this need, we developed a computational model of a CD4⁺ immune …

Antifungal Amphiphilic Aminoglycoside K20: Bioactivities And Mechanism Of Action, Sanjib K. Shrestha, Cheng-Wei Tom Chang, Nicole Meissner, John Oblad, Jaya P. Shrestha, Kevin N. Sorensen, Michelle M. Grilley, Jon Y. Takemoto

Chemistry and Biochemistry Faculty Publications

K20 is a novel amphiphilic antifungal aminoglycoside that is synthetically derived from the antibiotic kanamycin A. Reported here are investigations of K20′s antimicrobial activities, cytotoxicity, and fungicidal mechanism of action. In vitro growth inhibitory activities against a variety of human and plant pathogenic yeasts, filamentous fungi, and bacteria were determined using microbroth dilution assays and time-kill curve analyses, and hemolytic and animal cell cytotoxic activities were determined. Effects on Cryptococcus neoformans H-99 infectivity were determined with a preventive murine lung infection model. The antifungal mechanism of action was studied using intact fungal cells, yeast lipid mutants, and small unilamellar lipid …

Odd-Even Effects In Charge Transport Across N-Alkanethiolate-Based Sams, Mostafa Baghbanzadeh, Felice C. Simeone, Carleen M. Bowers, Kung Ching Liao, Martin Thuo, Mahdi Baghbanzadeh, Michael S. Miller, Tricia Breen Carmichael, George M. Whitesides

Chemistry and Biochemistry Publications

This paper compares rates of charge transport across self-assembled monolayers (SAMs) of n-alkanethiolates having odd and even numbers of carbon atoms (nodd and neven) using junctions with the structure MTS/SAM//Ga2O3/EGaIn (M = Au or Ag). Measurements of current density, J(V), across SAMs of n-alkanethiolates on AuTS and AgTS demonstrated a statistically significant odd-even effect on AuTS, but not on AgTS, that could be detected using this technique. Statistical analysis showed the values of tunneling current density across SAMs of n-alkanethiolates on AuTS with nodd and neven belonging to two separate sets, and while there is a significant difference between the …

Gaip Interacting Protein C-Terminus Regulates Autophagy And Exosome Biogenesis Of Pancreatic Cancer Through Metabolic Pathways, Santanu Bhattacharya, Krishnendu Pal, Anil K. Sharma, Shamit K. Dutta, Julie S. Lau, Irene K. Yan, Enfeng Wang, Ahmed Elkhanany, Khalid M. Alkharfy, Arunik Sanyal, Tushar C. Patel, Suresh T. Chari, Mark R. Spaller, Debabrata Mukhopadhyay

Dartmouth Scholarship

GAIP interacting protein C terminus (GIPC) is known to play an important role in a variety of physiological and disease states. In the present study, we have identified a novel role for GIPC as a master regulator of autophagy and the exocytotic pathways in cancer. We show that depletion of GIPC-induced autophagy in pancreatic cancer cells, as evident from the upregulation of the autophagy marker LC3II. We further report that GIPC regulates cellular trafficking pathways by modulating the secretion, biogenesis, and molecular composition of exosomes. We also identified the involvement of GIPC on metabolic stress pathways regulating autophagy and microvesicular …

Understanding Ten-Eleven Translocation-2 In Hematological And Nervous Systems, Feng Pan

FIU Electronic Theses and Dissertations

I proposed the study of two distinct aspects of Ten-Eleven Translocation 2 (TET2) protein for understanding specific functions in different body systems.

In Part I, I characterized the molecular mechanisms of Tet2 in the hematological system. As the second member of Ten-Eleven Translocation protein family, TET2 is frequently mutated in leukemic patients. Previous studies have shown that the TET2 mutations frequently occur in 20% myelodysplastic syndrome/myeloproliferative neoplasm (MDS/MPN), 10% T-cell lymphoma leukemia and 2% B-cell lymphoma leukemia. Genetic mouse models also display distinct phenotypes of various types of hematological malignancies. I performed 5-hydroxymethylcytosine (5hmC) chromatin immunoprecipitation sequencing (ChIP-Seq) and RNA …

Ultrasmooth Gold Surfaces Prepared By Chemical Mechanical Polishing For Applications In Nanoscience, Michael S. Miller, Michael Anthony Ferrato, Adrian Niec, Mark C. Biesinger, Tricia Breen Carmichael

Chemistry and Biochemistry Publications

For over 20 years, template stripping has been the best method for preparing ultrasmooth metal surfaces for studies of nanostructures. However, the organic adhesives used in the template stripping method are incompatible with many solvents, limiting the conditions that may subsequently be used to prepare samples; in addition, the film areas that can be reliably prepared are typically limited to ∼1 cm2. In this article, we present chemical-mechanical polishing (CMP) as an adhesive-free, scalable method of preparing ultrasmooth gold surfaces. In this process, a gold film is first deposited by e-beam evaporation onto a 76-mm-diameter silicon wafer. The CMP process …

Numerical Simulations Of In Vitro Nanoparticle Toxicity – The Case Of Poly(Amido Amine) Dendrimers., Marcus Maher, Pratap Naha, Sourav Prasanna Mukherjee, Hugh Byrne

Articles

A phenomenological rate equation model is constructed to numerically simulate nanoparticle uptake and subsequent cellular response. Polyamidoamine dendrimers (generations 4-6) are modelled and the temporal evolution of the intracellular cascade of; increased levels of reactive oxygen species, intracellular antioxidant species, caspase activation, mitochondrial membrane potential decay, tumour necrosis factor and interleukin generation is simulated, based on experimental observations.

The dose and generation dependence of several of these response factors are seen to well represent experimental observations at a range of time points. The model indicates that variations between responses of different cell-lines, including murine macrophages, human keratinocytes and colon cells, …

Gossypiboma: An Unrecognized And Under-Reported Problem In Pakistan, Abdul Rehman, Noor-Ul-Ain Baloch, Muhammad Awais

Department of Biological & Biomedical Sciences

No abstract provided.

Glutaredoxin 2 (Grx2) Gene Deletion Induces Early Onset Of Age-Dependent Cataracts In Mice, Hongli Wu, Yibo Yu, Larry David, Ye-Shih Ho, Marjorie . F. Lou

School of Veterinary and Biomedical Sciences: Faculty Publications

Glutaredoxin 2 (Grx2) is an isozyme of glutaredoxin1 (thioltransferase) present in the mitochondria and nucleus with disulfide reductase and peroxidase activities, and it controls thiol/ disulfide balance in cells. In this study, we investigated whether Grx2 gene deletion could induce faster age-related cataract formation and elucidated the biochemical changes effected by Grx2 gene deletion that may contribute to lens opacity. Slit lamp was used to examine the lenses in Grx2 knock-out (KO) mice and age-matched wild-type (WT) mice ages 1 to 16 months. In the Grx2 null mice, the lens nuclear opacity began at 5 months, 3 months sooner than …

Transcription Of The Streptococcus Pyogenes Hyaluronic Acid Capsule Biosynthesis Operon Is Regulated By Previously Unknown Upstream Elements, Marina Falaleeva, Oliwia W. Zurek, Robert L. Watkins, Robert W. Reed, Hadeel Ali, Paul Sumby, Jovanka M. Voyich, Natalia Korotkova

Molecular and Cellular Biochemistry Faculty Publications

The important human pathogen Streptococcus pyogenes (group A Streptococcus [GAS]) produces a hyaluronic acid (HA) capsule that plays critical roles in immune evasion. Previous studies showed that the hasABC operon encoding the capsule biosynthesis enzymes is under the control of a single promoter, P1, which is negatively regulated by the two-component regulatory system CovR/S. In this work, we characterize the sequence upstream of P1 and identify a novel regulatory region controlling transcription of the capsule biosynthesis operon in the M1 serotype strain MGAS2221. This region consists of a promoter, P2, which initiates transcription of a novel small RNA, HasS, an …

The Lineage-Specific Evolution Of Aquaporin Gene Clusters Facilitated Tetrapod Terrestrial Adaptation, Roderick Nigel Finn, François Chauvigné, Jón Baldur Hlidberg, Christopher P. Cutler, Joan Cerdà

Department of Biology Faculty Publications

A major physiological barrier for aquatic organisms adapting to terrestrial life is dessication in the aerial environment. This barrier was nevertheless overcome by the Devonian ancestors of extant Tetrapoda, but the origin of specific molecular mechanisms that solved this water problem remains largely unknown. Here we show that an ancient aquaporin gene cluster evolved specifically in the sarcopterygian lineage, and subsequently diverged into paralogous forms of AQP2, -5, or -6 to mediate water conservation in extant Tetrapoda. To determine the origin of these apomorphic genomic traits, we combined aquaporin sequencing from jawless and jawed vertebrates with broad taxon assembly of …

Deficiency Of Kruppel-Like Factor Klf4 In Myeloid-Derived Suppressor Cells Inhibits Tumor Pulmonary Metastasis In Mice Accompanied By Decreased Fibrocytes, Y. Shi, L. Ou, S. Han, M. Li, M. M. O. Pena, E. A. Pena, Chunming Liu, M. Nagarkatti, D. Fan, W. Ai

Molecular and Cellular Biochemistry Faculty Publications

The importance of immunosuppressive myeloid-derived suppressor cells (MDSCs) bearing monocyte markers in tumor metastasis has been well established. Recently, it was reported that these cells possess phenotypic plasticity and differentiate into fibrocytes, very distinct cells that are precursors of tumorigenic myofibroblasts. However, the importance of this transdifferentiation in tumor metastasis has not been explored. Here, we describe the role of MDSC-derived fibrocytes in tumor metastasis that is regulated by Kruppel-like factor 4 (KLF4), a transcription factor that is critical to monocyte differentiation and to promotion of cancer development. Using mouse metastasis models of melanoma and breast cancer, we found that …

The ​Oestrogen Receptor Alpha-Regulated Lncrna ​Neat1 Is A Critical Modulator Of Prostate Cancer, Dimple Chakravarty, Andrea Sboner, Sujit S. Nair, Eugenia Giannopoulou, Ruohan Li, +16 Additional Authors

Biochemistry and Molecular Medicine Faculty Publications

The androgen receptor (AR) plays a central role in establishing an oncogenic cascade that drives prostate cancer progression. Some prostate cancers escape androgen dependence and are often associated with an aggressive phenotype. The oestrogen receptor alpha (ERα) is expressed in prostate cancers, independent of AR status. However, the role of ERα remains elusive. Using a combination of chromatin immunoprecipitation (ChIP) and RNA-sequencing data, we identified an ERα-specific non-coding transcriptome signature. Among putatively ERα-regulated intergenic long non-coding RNAs (lncRNAs), we identified nuclear enriched abundant transcript 1 (NEAT1) as the most significantly overexpressed lncRNA in prostate cancer. Analysis of two large clinical …

An Active Role For The Ribosome In Determining The Fate Of Oxidized Mrna, Carrie L. Simms, Benjamin H. Hudson, John W. Mosior, Ali S. Rangwala, Hani S. Zaher

Biology Faculty Publications & Presentations

Chemical damage to RNA affects its functional properties and thus may pose a significant hurdle to the translational apparatus; however, the effects of damaged mRNA on the speed and accuracy of the decoding process and their interplay with quality-control processes are not known. Here, we systematically explore the effects of oxidative damage on the decoding process using a well-defined bacterial in vitro translation system. We find that the oxidative lesion 8-oxoguanosine (8-oxoG) reduces the rate of peptide-bond formation by more than three orders of magnitude independent of its position within the codon. Interestingly, 8-oxoG had little effect on the fidelity …

The Formin Fmnl3 Assembles Plasma Membrane Protrusions That Participate In Cell–Cell Adhesion, Timothy J. Gauvin, Lorna E. Young, Henry N. Higgs

Dartmouth Scholarship

FMNL3 is a vertebrate-specific formin protein previously shown to play a role in angiogenesis and cell migration. Here we define the cellular localization of endogenous FMNL3, the dynamics of GFP-tagged FMNL3 during cell migration, and the effects of FMNL3 suppression in mammalian culture cells. The majority of FMNL3 localizes in a punctate pattern, with >95% of these puncta being indistinguishable from the plasma membrane by fluorescence microscopy. A small number of dynamic cytoplasmic FMNL3 patches also exist, which enrich near cell–cell contact sites and fuse with the plasma membrane at these sites. These cytoplasmic puncta appear to be part of …

The Pathological Effects Of Ccr2+ Inflammatory Monocytes Are Amplified By An Ifnar1-Triggered Chemokine Feedback Loop In Highly Pathogenic Influenza Infection, Sue-Jane Lin, Ming Lo, Rei-Lin Kuo, Shin-Ru Shih, David M. Ojcius, Jean Lu, Chien-Kuo Lee, Hui-Chen Chen, Meei Yun Lin, Chuen-Miin Leu, Chia-Ni Lin, Ching-Hwa Tsai

All Dugoni School of Dentistry Faculty Articles

Background: Highly pathogenic influenza viruses cause high levels of morbidity, including excessive infiltration of leukocytes into the lungs, high viral loads and a cytokine storm. However, the details of how these pathological features unfold in severe influenza infections remain unclear. Accumulation of Gr1 + CD11b + myeloid cells has been observed in highly pathogenic influenza infections but it is not clear how and why they accumulate in the severely inflamed lung. In this study, we selected this cell population as a target to investigate the extreme inflammatory response during severe influenza infection.

Results: We established H1N1 IAV-infected mouse models using …

A 5', 8-Cyclo-2'-Deoxypurine Lesion Induces Trinucleotide Repeat Deletion Via A Unique Lesion Bypass By Dna Polymerase Β., Meng Xu, Yanhao Lai, Zhongliang Jiang, Michael A. Terzidis, Annalisa Masi, Chryssostomos Chatgilialoglu, Yuan Liu

Department of Chemistry and Biochemistry

5′,8-cyclo-2′-deoxypurines (cdPus) are common forms of oxidized DNA lesions resulting from endogenous and environmental oxidative stress such as ionizing radiation. The lesions can only be repaired by nucleotide excision repair with a low efficiency. This results in their accumulation in the genome that leads to stalling of the replication DNA polymerases and poor lesion bypass by translesion DNA polymerases. Trinucleotide repeats (TNRs) consist of tandem repeats of Gs and As and therefore are hotspots of cdPus. In this study, we provided the first evidence that both (5′R)- and (5′S)-5′,8-cyclo-2′-deoxyadenosine (cdA) in a CAG repeat tract caused CTG repeat deletion exclusively …

Mechanisms Of Arsenic Detoxification And Resistance, Jitesh Kannan Pillai

FIU Electronic Theses and Dissertations

Arsenic is a ubiquitous environmental toxic substance. As a consequence of continual exposure to arsenic, nearly every organism, from Escherichia coli to humans have evolved arsenic detoxification pathways. One of the pathways is extrusion of arsenic from inside the cells, thereby conferring resistance. The R773 arsRDABC operon in E. coli encodes an ArsAB efflux pump that confers resistance to arsenite. ArsA is the catalytic subunit of the pump, while ArsB forms the oxyanion conducting pathway. ArsD is an arsenite metallochaperone that binds arsenite and transfers it to ArsA. The interaction of ArsA and ArsD allows for resistance to As(III) at …

Kynurenine Aminotransferase Iii And Glutamine Transaminase L Are Identical Enzymes That Have Cysteine S-Conjugate Beta-Lyase Activity And Can Transaminate L-Selenomethionine, John T. Pinto, Boris F. Krasnikov, Steven Alcutt, Melanie E. Jones, Thambi Dorai, Arthur J L Cooper

NYMC Faculty Publications

Three of the four kynurenine aminotransferases (KAT I, II, and IV) that synthesize kynurenic acid, a neuromodulator, are identical to glutamine transaminase K (GTK), α-aminoadipate aminotransferase, and mitochondrial aspartate aminotransferase, respectively. GTK/KAT I and aspartate aminotransferase/KAT IV possess cysteine S-conjugate β-lyase activity. The gene for the former enzyme, GTK/KAT I, is listed in mammalian genome data banks as CCBL1 (cysteine conjugate beta-lyase 1). Also listed, despite the fact that no β-lyase activity has been assigned to the encoded protein in the genome data bank, is a CCBL2 (synonym KAT III). We show that human KAT III/CCBL2 possesses cysteine S-conjugate β-lyase …