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Articles 91 - 120 of 250

Full-Text Articles in Biochemistry

Killi-Data News (Winter), Tyrone Genade Mar 2018

Killi-Data News (Winter), Tyrone Genade

Killifish Research Review

This is the fourth edition, and concluding issue of the first volume, of Killi-Data News and I am happy that it has been well received by readers. At 25 pages this issue is a bit thin- ner than the last but this is because we agreed to make the cut-off for submissions the 1 st of December so we could get this edition out by the New Year. This is an exciting edition full of new species descrip- tions and analyses that will keep taxonomists busy for years to come. Costa has given us two molecular phylogenies on Melanorivulus as …

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Killi-Data News (Spring), Tyrone Genade Mar 2018

Killi-Data News (Spring), Tyrone Genade

Killifish Research Review

This is the start of Killi-Data News’ second year. In this first issue of the year we have the usual review of research pub- lications as well as input from Martin Reichard on his lab’s Nothobranchius research. Martin is responding to my reviews of his lab’s work in the previous edition. I am serious about making sure the content in this newsletter is reliable but I erred in the previous edition and Martin has written extensively to correct my mistake in the section “Erratum”. This reply is welcomed and owed to readers. I must confess that I don’t know everything …

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Mrub_1325, Mrub_1326, Mrub_1327, And Mrub_1328 Are Orthologs Of B_3454, B_3455, B_3457, B_3458, Respectively Found In Escherichia Coli Coding For A Branched Chain Amino Acid Atp Binding Cassette (Abc) Transporter System, Bennett Tomlin, Adam Buric, Dr. Lori Scott Jan 2018

Mrub_1325, Mrub_1326, Mrub_1327, And Mrub_1328 Are Orthologs Of B_3454, B_3455, B_3457, B_3458, Respectively Found In Escherichia Coli Coding For A Branched Chain Amino Acid Atp Binding Cassette (Abc) Transporter System, Bennett Tomlin, Adam Buric, Dr. Lori Scott

Meiothermus ruber Genome Analysis Project

In this project we investigated the biological function of the genes Mrub_1325, Mrub_1326, Mrub_1327, and Mrub_1328 (KEGG map number 02010). We predict these genes encode components of a Branched Chain Amino Acid ATP Binding Cassette (ABC) transporter: 1) Mrub_1325 (DNA coordinates 1357399-1358130 on the reverse strand) encodes the ATP binding domain; 2) Mrub_1326 (DNA coordinates 1358127-1359899 on the reverse strand) encodes the ATP-binding domain and permease domain; 3) Mrub_1327 (DNA coordinates 1359899-1360930 on the reverse strand) encodes a permease domain; and 4)Mrub_1328 (DNA coordinates 1711022-1712185 on the reverse strand) encodes the substrate binding domain. This system is not predicted to …

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Spontaneous Dna Damage To The Nuclear Genome Promotes Senescence, T Redox Imbalance And Aging, Andria R. Robinson, Matthew J. Yousefzadeh, Tania A. Rozgaja, Jin Wang, Xuesen Li, Jeremy S. Tilstra, Chelsea H. Feldman, Siobhan Q. Gregg, Caroline H. Johnson, Erin M. Skoda, Marie-Celine Frantz, Harris Bell-Temin, Hannah Pope-Varsalona, Aditi U. Gurkar, Luigi A. Nasto, Rena A.S. Robinson, Heike Fuhrmann-Stroissnigg, Jolanta Czerwinska, Sara J. Mcgowan, Nadiezhda Cantu-Madellin, Jamie B. Harris, Salony Maniar, Mark A. Ross, Christy E. Trussoni, Nicholas F. Larusso, Eugenia Cifuentes-Pagano, Patrick J. Pagano, Barbara Tudek, Nam V. Vo, Lora H. Rigatti, Patricia L. Opresko, Donna B. Stolz, Simon C. Watkins, Christin E. Burd, Claudette M. St, Croix, Gary Siuzdak, Nathan A. Yates, Paul D. Robbins, Yinsheng Wang, Peter Wipf, Eric E. Kelley, Laura J. Neidernhofer Jan 2018

Spontaneous Dna Damage To The Nuclear Genome Promotes Senescence, T Redox Imbalance And Aging, Andria R. Robinson, Matthew J. Yousefzadeh, Tania A. Rozgaja, Jin Wang, Xuesen Li, Jeremy S. Tilstra, Chelsea H. Feldman, Siobhan Q. Gregg, Caroline H. Johnson, Erin M. Skoda, Marie-Celine Frantz, Harris Bell-Temin, Hannah Pope-Varsalona, Aditi U. Gurkar, Luigi A. Nasto, Rena A.S. Robinson, Heike Fuhrmann-Stroissnigg, Jolanta Czerwinska, Sara J. Mcgowan, Nadiezhda Cantu-Madellin, Jamie B. Harris, Salony Maniar, Mark A. Ross, Christy E. Trussoni, Nicholas F. Larusso, Eugenia Cifuentes-Pagano, Patrick J. Pagano, Barbara Tudek, Nam V. Vo, Lora H. Rigatti, Patricia L. Opresko, Donna B. Stolz, Simon C. Watkins, Christin E. Burd, Claudette M. St, Croix, Gary Siuzdak, Nathan A. Yates, Paul D. Robbins, Yinsheng Wang, Peter Wipf, Eric E. Kelley, Laura J. Neidernhofer

Faculty & Staff Scholarship

Accumulation of senescent cells over time contributes to aging and age-related diseases. However, what drives senescence in vivo is not clear. Here we used a genetic approach to determine if spontaneous nuclear DNA damage is sufficient to initiate senescence in mammals. Ercc1-/Δ mice with reduced expression of ERCC1-XPF endonuclease have impaired capacity to repair the nuclear genome. Ercc1-/Δ mice accumulated spontaneous, oxidative DNA damage more rapidly than wild-type (WT) mice. As a consequence, senescent cells accumulated more rapidly in Ercc1-/Δ mice compared to repair-competent animals. However, the levels of DNA damage and senescent cells in Ercc1-/Δ mice never exceeded that …

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Asymmetric Patterns Of Small Molecule Transport After Nanosecond And Microsecond Electropermeabilization, Esin B. Sözer, C. Florencia Pocetti, P. Thomas Vernier Jan 2018

Asymmetric Patterns Of Small Molecule Transport After Nanosecond And Microsecond Electropermeabilization, Esin B. Sözer, C. Florencia Pocetti, P. Thomas Vernier

Bioelectrics Publications

Imaging of fluorescent small molecule transport into electropermeabilized cells reveals polarized patterns of entry, which must reflect in some way the mechanisms of the migration of these molecules across the compromised membrane barrier. In some reports, transport occurs primarily across the areas of the membrane nearest the positive electrode (anode), but in others cathode-facing entry dominates. Here we compare YO-PRO-1, propidium, and calcein uptake into U-937 cells after nanosecond (6 ns) and microsecond (220 µs) electric pulse exposures. Each of the three dyes exhibits a different pattern. Calcein shows no preference for anode- or cathode-facing entry that is detectable with …

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Interleukin-6 And Exercise; Early Evidence Of A Novel Myokine, Brendan Hogg Mr. Jan 2018

Interleukin-6 And Exercise; Early Evidence Of A Novel Myokine, Brendan Hogg Mr.

Graduate Student Theses, Dissertations, & Professional Papers

Interleukin-6 (IL-6) was first identified as a pleiotropic cytokine, with a host of body-wide functions. Cytokine functions are characterized by chronically elevated levels within various inflammatory states. In this regard, IL-6 is largely associated with the acute phase response to many stimuli and performs specific actions when produced from certain cell types. Accrued evidence indicates IL-6 release from skeletal muscle often includes myokine functions. Novel myokine functions are adaptive in nature, and as compared to inflammatory/cytokine roles, exhibit a transient time course. Following exercise plasma IL-6 peaks and returns to resting levels within 1-2 hours. In contrast, IL-6 is observed …

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Structure Of The Picornavirus Replication Platform: A Potential Drug Target For Inhibiting Virus Replication, Meghan Suzanne Warden Jan 2018

Structure Of The Picornavirus Replication Platform: A Potential Drug Target For Inhibiting Virus Replication, Meghan Suzanne Warden

Chemistry & Biochemistry Theses & Dissertations

Picornaviruses are small, positive-stranded RNA viruses, divided into twelve different genera. Members of the Picornaviridae family cause a wide range of human and animal diseases including the common cold, poliomyelitis, foot and mouth disease, and dilated cardiomyopathy. The picornavirus genome is replicated via a highly conserved mechanism involving a presumed cloverleaf structure located at the 5’ noncoding region of the virus genome. The 5’ cloverleaf consists of three stem loops (B, C, and D) and one stem (A), which interact with a variety of virus and host cell proteins during replication. In this dissertation, human rhinovirus serotype 14 (HRV-14) SLB …

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Insights Into The Therapeutic Potential Of Salt Inducible Kinase 1: A Novel Mechanism Of Metabolic Control, Randi Fitzgibbon Dec 2017

Insights Into The Therapeutic Potential Of Salt Inducible Kinase 1: A Novel Mechanism Of Metabolic Control, Randi Fitzgibbon

Dissertations and Theses (Open Access)

Salt inducible kinase 1 (SIK1) has been considered a stress-inducible kinase since it was first cloned in 1999. Continued efforts since this time have been dedicated to characterizing the structure and function of SIK1. Such research has laid the ground work for our understanding of SIK1 action and regulation in tissue and stimuli dependent manners. The fundamental findings of this dissertation continue in this tradition and include investigations of SIK1 regulatory mechanisms in skeletal muscle cells, the cellular and physiological effects of SIK1 loss of function in vitro and in vivo, and intracellular metabolic and mitochondrial regulation by this …

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Translational Fidelity, Mistranslation, And The Cellular Responses To Stress, Kyle Mohler, Michael Ibba Aug 2017

Translational Fidelity, Mistranslation, And The Cellular Responses To Stress, Kyle Mohler, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Faithful translation of mRNA into the corresponding polypeptide is a complex multistep process, requiring accurate amino acid selection, transfer RNA (tRNA) charging and mRNA decoding on the ribosome. Key players in this process are aminoacyl-tRNA synthetases (aaRSs), which not only catalyse the attachment of cognate amino acids to their respective tRNAs, but also selectively hydrolyse incorrectly activated non-cognate amino acids and/or misaminoacylated tRNAs. This aaRS proofreading provides quality control checkpoints that exclude non-cognate amino acids during translation, and in so doing helps to prevent the formation of an aberrant proteome. However, despite the intrinsic need for high accuracy during translation, …

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Carbonyl Reduction By Ymfi Completes The Modification Of Ef-P In Bacillus Subtilis To Prevent Accumulation Of An Inhibitory Modification State, Katherine R. Hummels, Anne Witzky, Andrei Rajkovic, Rodney Tollerson Ii, Lisa A. Jones, Michael Ibba, Daniel B. Kearns Aug 2017

Carbonyl Reduction By Ymfi Completes The Modification Of Ef-P In Bacillus Subtilis To Prevent Accumulation Of An Inhibitory Modification State, Katherine R. Hummels, Anne Witzky, Andrei Rajkovic, Rodney Tollerson Ii, Lisa A. Jones, Michael Ibba, Daniel B. Kearns

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Translation elongation factor P (EF‐P) in Bacillus subtilis is required for a form of surface migration called swarming motility. Furthermore, B. subtilis EF‐P is post‐translationally modified with a 5‐aminopentanol group but the pathway necessary for the synthesis and ligation of the modification is unknown. Here we determine that the protein YmfI catalyzes the reduction of EF‐P‐5 aminopentanone to EF‐P‐5 aminopentanol. In the absence of YmfI, accumulation of 5‐aminopentanonated EF‐P is inhibitory to swarming motility. Suppressor mutations that enhanced swarming in the absence of YmfI were found at two positions on EF‐P, including one that changed the conserved modification site (Lys …

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Elongation Factor P Interactions With The Ribosome Are Independent Of Pausing, Rodney Tollerson Ii, Anne Witzky, Michael Ibba Aug 2017

Elongation Factor P Interactions With The Ribosome Are Independent Of Pausing, Rodney Tollerson Ii, Anne Witzky, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Bacterial elongation factor P (EF-P) plays a pivotal role in the translation of polyproline motifs. To stimulate peptide bond formation, EF-P must enter the ribosome via an empty E-site. Using fluorescence-based single-molecule tracking, Mohapatra et al. (S. Mohapatra, H. Choi, X. Ge, S. Sanyal, and J. C. Weisshaar, mBio 8:e00300-17, 2017, https://doi.org/10.1128/mBio.00300-17 ) monitored the cellular distribution of EF-P and quantified the frequency of association between EF-P and the ribosome under various conditions. Findings from the study showed that EF-P has a localization pattern that is strikingly similar to that of ribosomes. Intriguingly, EF-P was seen to bind ribosomes more …

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Removal Of Endocrine Disrupting Compounds Using Membrane Bioreactor, Mohanad Ali Abdulsahib Kamaz Aug 2017

Removal Of Endocrine Disrupting Compounds Using Membrane Bioreactor, Mohanad Ali Abdulsahib Kamaz

Graduate Theses and Dissertations

The presence of endocrine disrupting compounds (EDCs) and pharmaceutically active compounds (PhAC) such as pesticides, personal care products, antibiotics and pharmaceutical compounds, in sewage, industrial, and domestic waters has extensively become the major concern for health and environmental organizations. These compounds have the ability to interact with mammalian endocrine system and disrupting their functions. The traditional activated sludge processes are designed to degrade solids, organic carbon and nitrogen loading. Although several treatment steps in a wastewater treatment plant can contribute to partial removal of EDCs, effective removal has been a challenge due to their resistant chemical and biological degradation and …

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The Mechanistic Requirements Of Passive H+ Import Through The Na, K-Atpase, Kevin S. Stanley Jun 2017

The Mechanistic Requirements Of Passive H+ Import Through The Na, K-Atpase, Kevin S. Stanley

Theses and Dissertations

This work focuses on the elucidation of the mechanism of passive proton import through the Na,K-ATPase. This enzyme uses the energy in ATP hydrolysis to exchange three intracellular Na+ for two extracellular K+ to maintain ion gradients within the cell, and while in the absence of physiological external Na+ and K+, the phosphorylated externally open (E2P) conformation passively imports protons, generating an inward current (IH). Chapter one reports on the effects of intracellular cations and nucleotides to shift the Na,K-ATPase into the E2P conformation. We identified that a combination of either internal Na+ and ATP or K+ and Pi. In …

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Molecular Regulation Of Stem Cell Behavior During Tissue Repair And Cancer Formation, Nestor J. Oviedo Mar 2017

Molecular Regulation Of Stem Cell Behavior During Tissue Repair And Cancer Formation, Nestor J. Oviedo

Science Seminar Series

Oviedo will be presenting his work on identifying the mechanisms of adult stem cell fate determination based on their topographical location in the adult body. Understanding stem cell fate determination is crucial because tissue repair and neoplastic growth are greater in anterior than in posterior regions of adult animals. Despite its critical implications for stem cell biology, carcinogenesis and regenerative medicine, this physiological phenomenon has remained overlooked. Recent findings from his group provide intriguing evidence implying DNA repair mechanisms and cellular signaling through post-translational modifications regulate stem cell fate decision depending on their topographical location in the adult body. We …

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Bioaccumulation Of Metallic Trace Elements And Antioxidant Enzyme Activities In Apfelbeckia Insculpta (L. Koch, 1867) (Diplopoda: Callipodida) From The Cave Hadži-Prodanova Pećina (Serbia), Jelena Vranković, Slavica Borković-Mitić, Bojan Ilić, Milanka Radulović, Slaviša Milošević, Slobodan Makarov, Bojan Mitić Feb 2017

Bioaccumulation Of Metallic Trace Elements And Antioxidant Enzyme Activities In Apfelbeckia Insculpta (L. Koch, 1867) (Diplopoda: Callipodida) From The Cave Hadži-Prodanova Pećina (Serbia), Jelena Vranković, Slavica Borković-Mitić, Bojan Ilić, Milanka Radulović, Slaviša Milošević, Slobodan Makarov, Bojan Mitić

International Journal of Speleology

The concentration of 10 metallic trace elements or MTE (Cu, Fe, Zn, Mn, As, Hg, Pb, Cd, Ni, and Cr) was measured in specimens of the troglophilic millipede Apfelbeckia insculpta (L. Koch, 1867) and sediment of the cave Hadži-Prodanova Pećina in western Serbia. Some MTE, like Fe and Mn, displayed much higher concentrations compared to other elements, both in the sediment and in the body of A. insculpta. On the other hand, estimation of the bioaccumulation factor (BAF) in both males and females of A. insculpta showed values greater than 1 for xenobiotic elements compared to those that are essential. …

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Editing Of Misaminoacylated Trna Controls The Sensitivity Of Amino Acid Stress Responses In Saccharomyces Cerevisiae, Kyle Mohler, Rebecca Mann, Tammy J. Bullwinkle, Kyle W. Hopkins, Lin Hwang, Noah M. Reynolds, Brandon Gassaway, Hans-Rudolph Aerni, Jesse Rinehart, Michael Polymenis, Kym F. Faull, Michael Ibba Feb 2017

Editing Of Misaminoacylated Trna Controls The Sensitivity Of Amino Acid Stress Responses In Saccharomyces Cerevisiae, Kyle Mohler, Rebecca Mann, Tammy J. Bullwinkle, Kyle W. Hopkins, Lin Hwang, Noah M. Reynolds, Brandon Gassaway, Hans-Rudolph Aerni, Jesse Rinehart, Michael Polymenis, Kym F. Faull, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Amino acid starvation activates the protein kinase Gcn2p, leading to changes in gene expression and translation. Gcn2p is activated by deacylated tRNA, which accumulates when tRNA aminoacylation is limited by lack of substrates or inhibition of synthesis. Pairing of amino acids and deacylated tRNAs is catalyzed by aminoacyl-tRNA synthetases, which use quality control pathways to maintain substrate specificity. Phenylalanyl-tRNA synthetase (PheRS) maintains specificity via an editing pathway that targets non-cognate Tyr-tRNAPhe. While the primary role of aaRS editing is to prevent misaminoacylation, we demonstrate editing of misaminoacylated tRNA is also required for detection of amino acid starvation by …

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Gestational Diabetes Mellitus And The Predisposing Factors, Syeda Sadia Fatima, Rehana Rehman, Faiza Alam, Sarosh Madhani, Bushra Chaudhry, Taseer Ahmed Khan Feb 2017

Gestational Diabetes Mellitus And The Predisposing Factors, Syeda Sadia Fatima, Rehana Rehman, Faiza Alam, Sarosh Madhani, Bushra Chaudhry, Taseer Ahmed Khan

Department of Biological & Biomedical Sciences

Objective: To evaluate the occurrence of gestational diabetes mellitus and its association with demographic and anthropometric variables in pregnant women.
Methods: This cross-sectional study was conducted at the Aga Khan University Hospital, Abbasi Shaheed Hospital and Memon Hospital in Karachi, from February 2014 to December 2015, and comprised pregnant women who were screened by 75-g 2-hour oral glucose tolerance test, (24-28 weeks of gestation) and classified as per the criteria of the International Association of Diabetes and Pregnancy Study Group. Weight, body mass index and serum glycated haemoglobin levels were measured. Women with pre-gestational diabetes were excluded. SPSS 21 was …

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Quality Control By Isoleucyl-Trna Synthetase Of Bacillus Subtilis Is Required For Efficient Sporulation, Elizabeth Kermgard, Zhou Yang, Annika-Marisa Michel, Rachel Simari, Jacqueline Wong, Michael Ibba, Beth A. Lazazzera Jan 2017

Quality Control By Isoleucyl-Trna Synthetase Of Bacillus Subtilis Is Required For Efficient Sporulation, Elizabeth Kermgard, Zhou Yang, Annika-Marisa Michel, Rachel Simari, Jacqueline Wong, Michael Ibba, Beth A. Lazazzera

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Isoleucyl-tRNA synthetase (IleRS) is an aminoacyl-tRNA synthetase whose essential function is to aminoacylate tRNAIle with isoleucine. Like some other aminoacyl-tRNA synthetases, IleRS can mischarge tRNAIle and correct this misacylation through a separate post-transfer editing function. To explore the biological significance of this editing function, we created a ileS(T233P) mutant of Bacillus subtilis that allows tRNAIle mischarging while retaining wild-type Ile-tRNAIle synthesis activity. As seen in other species defective for aminoacylation quality control, the growth rate of the ileS(T233P) strain was not significantly different from wild-type. When the ileS(T233P) strain was assessed for its ability to promote …

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Ms-Read: Quantitative Measurement Of Amino Acid Incorporation, Kyle Mohler, Hans-Rudolph Aerni, Brandon Gassaway, Jiqiang Ling, Michael Ibba, Jesse Rinehart Jan 2017

Ms-Read: Quantitative Measurement Of Amino Acid Incorporation, Kyle Mohler, Hans-Rudolph Aerni, Brandon Gassaway, Jiqiang Ling, Michael Ibba, Jesse Rinehart

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Ribosomal protein synthesis results in the genetically programmed incorporation of amino acids into a growing polypeptide chain. Faithful amino acid incorporation that accurately reflects the genetic code is critical to the structure and function of proteins as well as overall proteome integrity. Errors in protein synthesis are generally detrimental to cellular processes yet emerging evidence suggest that proteome diversity generated through mistranslation may be beneficial under certain conditions. Cumulative translational error rates have been determined at the organismal level, however codon specific error rates and the spectrum of misincorporation errors from system to system remain largely unexplored. In particular, until …

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Hyper-Activation Of Pp60(Src) Limits Nitric Oxide Signaling By Increasing Asymmetric Dimethylarginine Levels During Acute Lung Injury, Sanjiv Kumar, Xutong Sun, Satish Kumar Noonepalle, Qing Lu, Evgeny Zemskov, Ting Wang, Saurabh Aggarwal, Christine Gross, Shruti Sharma, Ankit A. Sesai, John D. Catravas Jan 2017

Hyper-Activation Of Pp60(Src) Limits Nitric Oxide Signaling By Increasing Asymmetric Dimethylarginine Levels During Acute Lung Injury, Sanjiv Kumar, Xutong Sun, Satish Kumar Noonepalle, Qing Lu, Evgeny Zemskov, Ting Wang, Saurabh Aggarwal, Christine Gross, Shruti Sharma, Ankit A. Sesai, John D. Catravas

Bioelectrics Publications

The molecular mechanisms by which the endothelial barrier becomes compromised during lipopolysaccharide (LPS) mediated acute lung injury (ALI) are still unresolved. We have previously reported that the disruption of the endothelial barrier is due, at least in part, to the uncoupling of endothelial nitric oxide synthase (eNOS) and increased peroxynitrite-mediated nitration of RhoA. The purpose of this study was to elucidate the molecular mechanisms by which LPS induces eNOS uncoupling during ALI. Exposure of pulmonary endothelial cells (PAEC) to LPS increased pp60Src activity and this correlated with an increase in nitric oxide (NO) production, but also an increase in …

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Rad Gtpase: Identification Of Novel Regulatory Mechanisms And A New Function In Modulation Of Bone Density And Marrow Adiposity, Catherine Nicole Kaminski Withers Jan 2017

Rad Gtpase: Identification Of Novel Regulatory Mechanisms And A New Function In Modulation Of Bone Density And Marrow Adiposity, Catherine Nicole Kaminski Withers

Theses and Dissertations--Molecular and Cellular Biochemistry

The small GTP-binding protein Rad (RRAD, Ras associated with diabetes) is the founding member of the RGK (Rad, Rem, Rem2, and Gem/Kir) family that regulates voltage-dependent calcium channel function. Given its expression in both excitable and non-excitable cell types, the control mechanisms for Rad regulation and the potential for novel functions for Rad beyond calcium channel modulation are open questions. Here we report a novel interaction between Rad and Enigma, a scaffolding protein that also binds to the E3 ubiquitin ligase Smad ubiquitin regulatory factor 1 (Smurf1). Overexpression of Smurf1, but not …

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Synthesis Of Rhamnosylated Arginine Glycopeptides And Determination Of The Glycosidic Linkage In Bacterial Elongation Factor P, Siyao Wang, Leo Corcilius, Phillip B. Sharp, Andrei Rajkovic, Michael Ibba, Benjamin L. Parker, Richard J. Payne Dec 2016

Synthesis Of Rhamnosylated Arginine Glycopeptides And Determination Of The Glycosidic Linkage In Bacterial Elongation Factor P, Siyao Wang, Leo Corcilius, Phillip B. Sharp, Andrei Rajkovic, Michael Ibba, Benjamin L. Parker, Richard J. Payne

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

A new class of N-linked protein glycosylation – arginine rhamnosylation – has recently been discovered as a critical modification for the function of bacterial elongation factor P (EF-P). Herein, we describe the synthesis of suitably protected α- and β-rhamnosylated arginine amino acid “cassettes” that can be directly installed into rhamnosylated peptides. Preparation of a proteolytic fragment of Pseudomonas aeruginosa EF-P bearing both α- and β-rhamnosylated arginine enabled the unequivocal determination of the native glycosidic linkage to be α through 2D NMR and nano-UHPLC-tandem mass spectrometry studies.

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The Complex Evolutionary History Of Aminoacyl-Trna Synthetases, Anargyros Chaliotis, Panayotis Vlastaridis, Dimitris Mossialos, Michael Ibba, Hubert D. Becker, Constantinos Stathopoulos, Grigorios D. Amoutzias Nov 2016

The Complex Evolutionary History Of Aminoacyl-Trna Synthetases, Anargyros Chaliotis, Panayotis Vlastaridis, Dimitris Mossialos, Michael Ibba, Hubert D. Becker, Constantinos Stathopoulos, Grigorios D. Amoutzias

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Aminoacyl-tRNA synthetases (AARSs) are a superfamily of enzymes responsible for the faithful translation of the genetic code and have lately become a prominent target for synthetic biologists. Our large-scale analysis of >2500 prokaryotic genomes reveals the complex evolutionary history of these enzymes and their paralogs, in which horizontal gene transfer played an important role. These results show that a widespread belief in the evolutionary stability of this superfamily is misconceived. Although AlaRS, GlyRS, LeuRS, IleRS, ValRS are the most stable members of the family, GluRS, LysRS and CysRS often have paralogs, whereas AsnRS, GlnRS, PylRS and SepRS are often absent …

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Design Of Novel Ion Channel Modulators, Vladimir Yarov-Yarovoy Nov 2016

Design Of Novel Ion Channel Modulators, Vladimir Yarov-Yarovoy

Science Seminar Series

Function and modulation of neuronal sodium channels are critical for the neuromodulation of electrical excitability and synaptic transmission in neurons - the basis for many aspects of signal transduction, learning, memory and physiological regulation. Mutations in neuronal voltage-gated sodium channel genes are responsible for various human neurological disorders. Furthermore, human neuronal voltage-gated sodium channels are primary targets of therapeutic drugs used as local anesthetics and for treatment of neurological and cardiac disorders. Yarov-Yarovoy's lab is working on rational design of novel therapeutically useful blockers of voltage-gated sodium channels for treatment of pain and epilepsy. Serious, chronic pain affects at least …

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Isoacceptor Specific Characterization Of Trna Aminoacylation And Misacylation In Vivo, Kyle Mohler, Rebecca Mann, Michael Ibba Sep 2016

Isoacceptor Specific Characterization Of Trna Aminoacylation And Misacylation In Vivo, Kyle Mohler, Rebecca Mann, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Amino acid misincorporation during protein synthesis occurs due to misacylation of tRNAs or defects in decoding at the ribosome. While misincorporation of amino acids has been observed in a variety of contexts, less work has been done to directly assess the extent to which specific tRNAs are misacylated in vivo, and the identity of the misacylated amino acid moiety. Here we describe tRNA isoacceptor specific aminoacylation profiling (ISAP), a method to identify and quantify the amino acids attached to a tRNA species in vivo. ISAP allows compilation of aminoacylation profiles for specific isoacceptors tRNAs. To demonstrate the efficacy and …

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Maintenance Of Transcription-Translation Coupling By Elongation Factor P, Sara Elgamal, Irina Artsimovitch, Michael Ibba Sep 2016

Maintenance Of Transcription-Translation Coupling By Elongation Factor P, Sara Elgamal, Irina Artsimovitch, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Under conditions of tight coupling between translation and transcription, the ribosome enables synthesis of full-length mRNAs by preventing both formation of intrinsic terminator hairpins and loading of the transcription termination factor Rho. While previous studies have focused on transcription factors, we investigated the role of Escherichia coli elongation factor P (EF-P), an elongation factor required for efficient translation of mRNAs containing consecutive proline codons, in maintaining coupled translation and transcription. In the absence of EF-P, the presence of Rho utilization (rut) sites led to an ~30-fold decrease in translation of polyproline-encoding mRNAs. Coexpression of the Rho inhibitor Psu …

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Intestinal Cytoplasmic Lipid Droplets, Associated Proteins, And The Regulation Of Dietary Fat Absorption, Theresa M. D'Aquila Aug 2016

Intestinal Cytoplasmic Lipid Droplets, Associated Proteins, And The Regulation Of Dietary Fat Absorption, Theresa M. D'Aquila

Open Access Dissertations

Dietary fat provides essential nutrients, contributes to energy balance, and regulates blood lipid concentrations. These functions are important to health, but can also become dysregulated and contribute to diseases such as obesity, diabetes, and cardiovascular disease. The small intestine absorbs dietary fat through an efficient multi step process of digestion, uptake, metabolism, and secretion or storage. When dietary fat is taken up by the absorptive cells of the small intestine, enterocytes, it can be secreted into circulation where it contributes to blood lipid levels or temporarily stored in cytoplasmic lipid droplets (CLDs). The objective of this dissertation is to investigate …

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Translation Control Of Swarming Proficiency In Bacillus Subtilis By 5-Amino-Pentanolylated Elongation Factor P, Andrei Rajkovic, Katherine R. Hummels, Anne Witzky, Sarah Erickson, Philip R. Gafken, Julian P. Whitelegge, Kym F. Faull, Daniel B. Kearns, Michael Ibba May 2016

Translation Control Of Swarming Proficiency In Bacillus Subtilis By 5-Amino-Pentanolylated Elongation Factor P, Andrei Rajkovic, Katherine R. Hummels, Anne Witzky, Sarah Erickson, Philip R. Gafken, Julian P. Whitelegge, Kym F. Faull, Daniel B. Kearns, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Elongation factor P (EF-P) accelerates diprolyl synthesis and requires a posttranslational modification to maintain proteostasis. Two phylogenetically distinct EF-P modification pathways have been described and are encoded in the majority of Gram-negative bacteria, but neither is present in Gram-positive bacteria. Prior work suggested that the EF-P-encoding gene (efp) primarily supports Bacillus subtilis swarming differentiation, whereas EF-P in Gram-negative bacteria has a more global housekeeping role, prompting our investigation to determine whether EF-P is modified and how it impacts gene expression in motile cells. We identified a 5-aminopentanol moiety attached to Lys32 of B. subtilis EF-P that is …

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Multiple Quality Control Pathways Limit Non-Protein Amino Acid Use By Yeast Cytoplasmic Phenylalanyl-Trna Synthetase, Adil Moghal, Lin Hwang, Kym F. Faull, Michael Ibba May 2016

Multiple Quality Control Pathways Limit Non-Protein Amino Acid Use By Yeast Cytoplasmic Phenylalanyl-Trna Synthetase, Adil Moghal, Lin Hwang, Kym F. Faull, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Non-protein amino acids, particularly isomers of the proteinogenic amino acids, present a threat to proteome integrity if they are mistakenly inserted into proteins. Quality control during aminoacyl-tRNA synthesis reduces non-protein amino acid incorporation by both substrate discrimination and proofreading. For example phenylalanyl-tRNA synthetase (PheRS) proofreads the non-protein hydroxylated phenylalanine derivative m-Tyr after its attachment to tRNAPhe. We now show in Saccharomyces cerevisiae that PheRS misacylation of tRNAPhe with the more abundant Phe oxidation product o-Tyr is limited by kinetic discrimination against o-Tyr-AMP in the transfer step followed by o-Tyr-AMP release from the synthetic …

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Purification And Characterization Of Antibodies Against Killifish Hif-1Α, Janet Gonzalez-Rosario May 2016

Purification And Characterization Of Antibodies Against Killifish Hif-1Α, Janet Gonzalez-Rosario

LSU New Orleans Theses and Dissertations

Many fish face low oxygen concentrations (hypoxia) in their natural environments, and they respond to hypoxia through a variety of behavioral, physiological, and cellular mechanisms. Some of these responses involve changes in gene expression. In mammals, the hypoxia inducible factor (HIF) family of transcription factors are the “master regulators” of gene expression during hypoxia, but the study of HIF in fish has been hampered by the lack of reagents to detect this protein in non-mammalian vertebrates. The goals of this thesis are to affinity purify antibodies against HIF from the killifish Fundulus heteroclitus and use them to recover and quantify …

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