Medicine and Health Sciences Commons^™

Genome-Wide Mutagenesis To Investigate The N-Terminal Methylome: The Protective Effects Of Hsp31 And Other Methylated Proteins In Yeast, James Rooney, Jacob Lindsey

The Journal of Purdue Undergraduate Research

The purpose of this study was to understand the role of methylation in regulating the cellular stress response of Hsp31 in Saccharomyces cerevisiae yeast cells. Hsp31 is known to be methylated by the N-terminal methyltransferase Tae1. Changing the methylation site can affect the methylation status of Hsp31, which may play a role in the protective activity of Hsp31 against cellular stress. GLO1 is a gene in yeast involved in catalyzing the detoxification of methylglyoxal (MGO), which is a by-product of glycolysis. We established that S. cerevisiae in the glo1Δ and background is sensitive to cellular stress by MGO. Mutant strains …

Functional Assessment Of Missense Variants In The Abcc6 Gene Implicated In Pseudoxanthoma Elasticum, A Heritable Ectopic Mineralization Disorder., Luke Kowal, Jianhe Huang, Hongbin Luo, Jagmohan Singh, Adam E Snook, Jouni Uitto, Qiaoli Li

Department of Pharmacology and Experimental Therapeutics Faculty Papers

Pseudoxanthoma elasticum, a heritable multisystem ectopic mineralization disorder, is caused by inactivating mutations in the ABCC6 gene. The encoded protein, ABCC6, a transmembrane transporter, has a specialized efflux function in hepatocytes by contributing to plasma levels of inorganic pyrophosphate, a potent inhibitor of mineralization in soft connective tissues. Reduced plasma inorganic pyrophosphate levels underlie the ectopic mineralization in pseudoxanthoma elasticum. In this study, we characterized the pathogenicity of three human ABCC6 missense variants using an adenovirus-mediated liver-specific ABCC6 transgene expression system in an Abcc6

Covid-19: The Vaccine Race Continues, L. Hayley Burgess, Carley Castelein, Andrew Rubio, Mandelin K. Cooper

HCA Healthcare Journal of Medicine

Over a year has passed since the discovery of SARS-CoV-2 and the subsequent COVID-19 pandemic. As mitigation efforts continue, COVID-19 has claimed over half a million lives in the United States and 3.1 million lives globally. The development and availability of vaccines delivering immunity to prevent COVID-19 offers hope to end the pandemic.

Emergency use authorizations from the Food and Drug Administration have been issued in the United States for three vaccines, one each from Pfizer-BioNTech, Moderna and Janssen/J&J. Pfizer-BioNTech and Moderna are both mRNA vaccines with efficacy of 95% and 94.1% respectively, while the vector-based vaccine from Janssen/J&J has …

Genomic Context And Tp53 Allele Frequency Define Clinical Outcomes In Tp53-Mutated Myelodysplastic Syndromes, Guillermo Montalban-Bravo, Rashmi Kanagal-Shamanna, Christopher B. Benton, Caleb A. Class, Kelly S. Chien, Koji Sasaki ,, Kiran Naqvi, Yesid Alvarado, Tapan M. Kadia, Farhad Ravandi, Naval Daver, Koichi Takahashi, Elias Jabbour, Gautham Borthakur, Naveen Pemmaraju, Marina Konopleva, Kelly A. Soltysiak, Sherry R. Pierce, Carlos E. Bueso-Ramos, Keyur P. Patel, Hagop Kantarjian, Guillermo Garcia-Manero

Scholarship and Professional Work – COPHS

TP53 mutations are associated with adverse outcomes and shorter response to hypomethylating agents (HMAs) in myelodysplastic syndrome (MDS). Limited data have evaluated the impact of the type, number, and patterns of TP53 mutations in response outcomes and prognosis of MDS. We evaluated the clinicopathologic characteristics, outcomes, and response to therapy of 261 patients with MDS and TP53 mutations. Median age was 68 years (range, 18-80 years). A total of 217 patients (83%) had a complex karyotype. TP53 mutations were detected at a median variant allele frequency (VAF) of 0.39 (range, 0.01-0.94). TP53 deletion was associated with lower overall response rate …

The Role Of Human Dopamine Transporter In Neuroaids, Jun Zhu, Subramaniam Ananthan, Chang-Guo Zhan

Molecular Modeling and Biopharmaceutical Center Faculty Publications

HIV-associated neurocognitive disorder (HAND) remains highly prevalent in HIV infected individuals and represents a special group of neuropathological disorders, which are associated with HIV-1 viral proteins, such as transactivator of transcription (Tat) protein. Cocaine abuse increases the incidence of HAND and exacerbates its severity by enhancing viral replication. Perturbation of dopaminergic transmission has been implicated as a risk factor of HAND. The presynaptic dopamine (DA) transporter (DAT) is essential for DA homeostasis and dopaminergic modulation of the brain function including cognition. Tat and cocaine synergistically elevate synaptic DA levels by acting directly on human DAT (hDAT), ultimately leading to dysregulation …

High Activity Mutants Of Cocaine Esterase For Cocaine Hydrolysis, Chang-Guo Zhan, Fang Zheng, Lei Fang

Pharmaceutical Sciences Faculty Patents

The Bacterial cocaine esterase (CocE) mutants disclosed herein each have enhanced catalytic efficiency for ( -)cocaine, as compared to CocE mutants in the prior art, including CocE mutant E172-173. The presently-disclosed subject matter further includes a pharmaceutical composition including a mutant of bacterial cocaine hydrolase, as described herein, and a suitable pharmaceutical carrier. The presently-disclosed subject matter further includes a method of treating a cocaine-induced condition comprising administering to an individual an effective amount of a mutant of bacterial cocaine hydrolase variant, as disclosed herein, to accelerate cocaine metabolism and produce biologically inactive metabolites.

Advances And Perspectives In Genetics Of Congenital Thyroid Disorders Associated With Thyroglobulin Gene Mutations, Héctor M. Targovnik, Cintia E. Citterio, Sofi Siffo, Carina M. Rivolta

Pharmacy Faculty Articles and Research

Dyshormonogenesis due to thyroglobulin (TG) gene mutations is a rare cause of congenital hypothyroidism with an estimated incidence of approximately 1 in 100,000 newborns. The TG gene is organized in 48 exons, spanning over 270 kb on human chromosome 8q24. The human TG mRNA is 8.5 Kb long and the preprotein monomer is composed of a 19 amino acids signal peptide followed by a 2749 residues polypeptide. Until now, one hundred seventeen deleterious mutations in the human TG gene have been identified and characterized, originating structural changes in the protein that alter the normal protein folding, assembly and …

An Arginine Finger Regulates The Sequential Action Of Asymmetrical Hexameric Atpase In The Double-Stranded Dna Translocation Motor, Zhengyi Zhao, Gian Marco De-Donatis, Chad T. Schwartz, Huaming Fang, Jingyuan Li, Peixuan Guo

Pharmaceutical Sciences Faculty Publications

Biological motors are ubiquitous in living systems. Currently, how the motor components coordinate the unidirectional motion is elusive in most cases. Here, we report that the sequential action of the ATPase ring in the DNA packaging motor of bacteriophage ϕ29 is regulated by an arginine finger that extends from one ATPase subunit to the adjacent unit to promote noncovalent dimer formation. Mutation of the arginine finger resulted in the interruption of ATPase oligomerization, ATP binding/hydrolysis, and DNA translocation. Dimer formation reappeared when arginine mutants were mixed with other ATPase subunits that can offer the arginine to promote their interaction. Ultracentrifugation …

Samhd1 Is A Single-Stranded Nucleic Acid Binding Protein With No Active Site-Associated Nuclease Activity., Kyle J. Seamon, Zhiqiang Sun, Luda S. Shlyakhtenko, Yuri L. Lyubchenko, James T. Stivers

Journal Articles: Pharmaceutical Sciences

The HIV-1 restriction factor SAMHD1 is a tetrameric enzyme activated by guanine nucleotides with dNTP triphosphate hydrolase activity (dNTPase). In addition to this established activity, there have been a series of conflicting reports as to whether the enzyme also possesses single-stranded DNA and/or RNA 3'-5' exonuclease activity. SAMHD1 was purified using three chromatography steps, over which the DNase activity was largely separated from the dNTPase activity, but the RNase activity persisted. Surprisingly, we found that catalytic and nucleotide activator site mutants of SAMHD1 with no dNTPase activity retained the exonuclease activities. Thus, the exonuclease activity cannot be associated with any …

Molecular Mechanism For Depolarization-Induced Modulation Of Kv Channel Closure, Alain J. Labro, Jerome J. Lacroix, Carlos A. Villalba-Galea, Dirk J. Snyders, Francisco Bezanilla

School of Pharmacy Faculty Articles

Voltage-dependent potassium (Kv) channels provide the repolarizing power that shapes the action potential duration and helps control the firing frequency of neurons. The K(+) permeation through the channel pore is controlled by an intracellularly located bundle-crossing (BC) gate that communicates with the voltage-sensing domains (VSDs). During prolonged membrane depolarizations, most Kv channels display C-type inactivation that halts K(+) conduction through constriction of the K(+) selectivity filter. Besides triggering C-type inactivation, we show that in Shaker and Kv1.2 channels (expressed in Xenopus laevis oocytes), prolonged membrane depolarizations also slow down the kinetics of VSD deactivation and BC gate closure during the …

Dna Synapsis Through Transient Tetramerization Triggers Cleavage By Ecl18ki Restriction Enzyme., Mindaugas Zaremba, Amelia Owsicka, Gintautas Tamulaitis, Giedrius Sasnauskas, Luda S. Shlyakhtenko, Alexander Y. Lushnikov, Yuri L. Lyubchenko, Niels Laurens, Bram Van Den Broek, Gijs J.L. Wuite, Virginijus Siksnys

Journal Articles: Pharmaceutical Sciences

To cut DNA at their target sites, restriction enzymes assemble into different oligomeric structures. The Ecl18kI endonuclease in the crystal is arranged as a tetramer made of two dimers each bound to a DNA copy. However, free in solution Ecl18kI is a dimer. To find out whether the Ecl18kI dimer or tetramer represents the functionally important assembly, we generated mutants aimed at disrupting the putative dimer-dimer interface and analysed the functional properties of Ecl18kI and mutant variants. We show by atomic force microscopy that on two-site DNA, Ecl18kI loops out an intervening DNA fragment and forms a tetramer. Using the …

A Gene Expression Predictor Of Response To Egfr-Targeted Therapy Stratifies Progression-Free Survival To Cetuximab In Kras Wild-Type Metastatic Colorectal Cancer, Justin M. Balko, Esther P. Black

Pharmaceutical Sciences Faculty Publications

BACKGROUND: The anti-EGFR monoclonal antibody cetuximab is used in metastatic colorectal cancer (CRC), and predicting responsive patients garners great interest, due to the high cost of therapy. Mutations in the KRAS gene occur in ~40% of CRC and are a negative predictor of response to cetuximab. However, many KRAS-wildtype patients do not benefit from cetuximab. We previously published a gene expression predictor of sensitivity to erlotinib, an EGFR inhibitor. The purpose of this study was to determine if this predictor could identify KRAS-wildtype CRC patients who will benefit from cetuximab therapy.

METHODS: Microarray data from 80 metastatic CRC patients subsequently …

Triplet Repeat Dna Structures And Human Genetic Disease: Dynamic Mutations From Dynamic Dna., Richard R. Sinden, Vladimir N. Potaman, Elena A. Oussatcheva, Christopher E. Pearson, Yuri L. Lyubchenko, Luda S. Shlyakhtenko

Journal Articles: Pharmaceutical Sciences

Fourteen genetic neurodegenerative diseases and three fragile sites have been associated with the expansion of (CTG)n (CAG)n, (CGG)n (CCG)n, or (GAA)n (TTC)n repeat tracts. Different models have been proposed for the expansion of triplet repeats, most of which presume the formation of alternative DNA structures in repeat tracts. One of the most likely structures, slipped strand DNA, may stably and reproducibly form within triplet repeat sequences. The propensity to form slipped strand DNA is proportional to the length and homogeneity of the repeat tract. The remarkable stability of slipped strand DNA may, in part, be due to loop-loop interactions facilitated …