Life Sciences Commons^™

The Replication Initiator Of The Cholera Pathogen’S Second Chromosome Shows Structural Similarity To Plasmid Initiators, Natalia Orlova, Matthew Gerding, Olha Ivashkiv, Paul Dominic B. Olinares, Brian T. Chait, Matthew K. Waldor, David Jeruzalmi

Publications and Research

The conserved DnaA-oriC system is used to initiate replication of primary chromosomes throughout the bacterial kingdom; however, bacteria with multipartite genomes evolved distinct systems to initiate replication of secondary chromosomes. In the cholera pathogen, Vibrio cholerae, and in related species, secondary chromosome replication requires the RctB initiator protein. Here, we show that RctB consists of four domains. The structure of its central two domains resembles that of several plasmid replication initiators. RctB contains at least three DNA binding winged-helix-turn-helix motifs, and mutations within any of these severely compromise biological activity. In the structure, RctB adopts a headto- head dimeric configuration …

Hiv Glycoprotein Gp120 Impairs Fast Axonal Transport By Activating Tak1 Signaling Pathways, Sarah H. Berth, Nichole Mesnard-Hoaglin, Bin Wang, Hajwa Kim, Yuyu Song, Maria Sapar, Gerardo Morfini, Scott T. Brady

Publications and Research

Sensory neuropathies are the most common neurological complication of HIV. Of these, distal sensory polyneuropathy (DSP) is directly caused by HIV infection and characterized by length-dependent axonal degeneration of dorsal root ganglion (DRG) neurons. Mechanisms for axonal degeneration in DSP remain unclear, but recent experiments revealed that the HIV glycoprotein gp120 is internalized and localized within axons of DRG neurons. Based on these findings, we investigated whether intra-axonal gp120 might impair fast axonal transport (FAT), a cellular process critical for appropriate maintenance of the axonal compartment. Significantly, we found that gp120 severely impaired both anterograde and retrograde FAT. Providing a …

Ben Domain Protein Elba2 Can Functionally Substitute For Linker Histone H1 In Drosophila In Vivo, Na Xu, Xingwu Lu, Harsh Kavi, Alexander V. Emelyanov, Travis J. Bernardo, Elena Vershilova, Arthur I. Skoultchi, Dmitry V. Fyodorov

Publications and Research

Metazoan linker histones are essential for development and play crucial roles in organization of chromatin, modification of epigenetic states and regulation of genetic activity. Vertebrates express multiple linker histone H1 isoforms, which may function redundantly. In contrast, H1 isoforms are not present in Dipterans, including D. melanogaster, except for an embryo-specific, distantly related dBigH1. Here we show that Drosophila BEN domain protein Elba2, which is expressed in early embryos and was hypothesized to have insulator-specific functions, can compensate for the loss of H1 in vivo. Although the Elba2 gene is not essential, its mutation causes a disruption of normal internucleosomal …

Implementing An Mhealth System For Substance Use Disorders In Primary Care: A Mixed Methods Study Of Clinicians’ Initial Expectations And First Year Experiences, Marie-Louise Mares, David H. Gustafson, Joseph E. Glass, Andrew Quanbeck, Helene Mcdowell, Fiona Mctavish, Amy K. Atwood, Lisa A. Marsch, Chanetelle Thomas, Dhavan Shah, Randall Brown, Andrew Isham, Mary Jane Nealon, Victoria Ward

Publications and Research

Background: Millions of Americans need but don’t receive treatment for substance use, and evidence suggests that addiction-focused interventions on smart phones could support their recovery. There is little research on implementation of addiction-related interventions in primary care, particularly in Federally Qualified Health Centers (FQHCs) that provide primary care to underserved populations. We used mixed methods to examine three FQHCs’ implementation of Seva, a smart-phone app that offers patients online support/discussion, health-tracking, and tools for coping with cravings, and offers clinicians information about patients’ health tracking and relapses. We examined (a) clinicians’ initial perspectives about implementing Seva, and (b) the first …

Fhf-Independent Conduction Of Action Potentials Along The Leak-Resistant Cerebellar Granule Cell Axon, Katarzyna Dover, Christopher Marra, Sergio Solinas, Marko Popovic, Sathyaa Subramaniyam, Dejan Zecevic, Egidio D'Angelo, Mitchell Goldfarb

Publications and Research

Neurons in vertebrate central nervous systems initiate and conduct sodium action potentials in distinct subcellular compartments that differ architecturally and electrically. Here, we report several unanticipated passive and active properties of the cerebellar granule cell’s unmyelinated axon. Whereas spike initiation at the axon initial segment relies on sodium channel (Nav)-associated fibroblast growth factor homologous factor (FHF) proteins to delay Nav inactivation, distal axonal Navs show little FHF association or FHF requirement for high-frequency transmission, velocity and waveforms of conducting action potentials. In addition, leak conductance density along the distal axon is estimated as o1% that of somatodendritic membrane. The faster …

Nmr And Structural Data For Connexin 32 And Connexin 26 N-Terminal Peptides, Yuskel Batir, Thaddeus A. Bargiello, Terry L. Dowd

Publications and Research

In this article we present 1H and 13C chemical shift assignments, secondary structural propensity data and normalized temperature coefficient data for N-terminal peptides of Connexin 26(Cx26), Cx26G12R and Cx32G12R mutants seen in syndromic deafness and Charcot Marie Tooth Disease respectively, published in “Structural Studies of N-Terminal Mutants of Connexin 26 and Connexin 32 Using 1HNMR Spectroscopy” (Y.Batir,T.A.Bargiello,T.L.Dowd, 2016)[1]. The mutation G12R affects thestructure of both Cx26 and Cx32 peptides differently. We present data from secondary structure propensity chemical shift analysis which calculates a secondary structurepropensity (SSP) score for both disordered or folded peptides and proteins using the difference between the …

Insights Into The Molecular Roles Of Heparan Sulfate Proteoglycans (Hspgs-Syndecans) In Autocrine And Paracrine Growth Factor Signaling In The Pathogenesis Of Hodgkin's Lymphoma, Rajendra Ghardbaran

Publications and Research

Syndecans (SDC, SYND) comprise a group of four structurally related type 1 transmembrane heparan sulfate proteoglycans (HSPGs) that play important roles in tumorigenic processes. SDCs exert signaling via their protein cores and their conserved transmembrane and cytoplasmic domains or by forming complexes with growth factors (GFs). In classical Hodgkin's lymphoma (cHL), a lymphoid neoplasm of predominantly B cell origin, SDC1 and SDC4 are the active SDCs, and a number of GF (vascular endothelial growth factor, fibroblast growth factor, etc.) signaling pathways have been studied. However, despite extensive pre-clinical and clinical research on SDC-mediated GF signaling in many cancer types, there …

Single-Nucleotide Polymorphisms And Markers Of Oxidative Stress In Healthy Women, Albina N. Minlikeeva, Richard W. Browne, Heather M. Ochs-Balcom, Catalin Marian, Peter G. Shields, Maurizio Trevisan, Shiva Krishnan, Ramakrishna Modali, Michael Seddon, Terese Lehman, Jo L. Freudenheim

Publications and Research

Purpose There is accumulating evidence that oxidative stress is an important contributor to carcinogenesis. We hypothesized that genetic variation in genes involved in maintaining antioxidant/ oxidant balance would be associated with overall oxidative stress.

Methods We examined associations between single nucleotide polymorphisms (SNPs) in MnSOD, GSTP1, GSTM1, GPX1, GPX3, and CAT genes and thiobarbituric acid-reactive substances (TBARS), a blood biomarker of oxidative damage, in healthy white women randomly selected from Western New York (n = 1402). We used general linear models to calculate age-adjusted geometric means of TBARS across the variants. We also examined the associations within strata of menopausal …

Antioxidant And Hepatoprotective Effects Of Procyanidins Fromwild Grape (Vitis Amurensis) Seeds In Ethanol-Induced Cells And Rats, Min Ji Bak, Van-Long Truong, Se-Yeon Ko, Xuan Ngan Giang Nguyen, Pajaree Ingkasupart, Mira Jun, Jin Young Shin, Woo-Sik Jeong

Publications and Research

In the present study, we characterized the antioxidant and hepatoprotective mechanisms underlying of wild grape seed procyanidins (WGP) against oxidative stress damage in ethanol-treated HepG2 cell and Sprague-Dawley (SD)-rat models. In HepG2 cells, WGP not only diminished the ethanol (EtOH, 100 mM)-induced reactive oxygen species (ROS) formation and cytochrome P450 2E1 (CYP2E1) expression, but also renovated both the activity and expression of antioxidant enzymes including catalase, superoxide dismutase, and glutathione peroxidase. Additionally, to investigate the hepatoprotective effect of WGP, rats were orally administered 10 or 50 mg/kg WGP once daily for seven days prior to the single oral administration of …

Molecular Self-Assembly Strategy For Generating Catalytic Hybrid Polypeptides, Yoshiaki Maeda, Justin Fang, Yasuhiro Ikezoe, Douglas H. Pike, Vikas Nanda, Hiroshi Matsui

Publications and Research

Recently, catalytic peptides were introduced that mimicked protease activities and showed promising selectivity of products even in organic solvents where protease cannot perform well. However, their catalytic efficiency was extremely low compared to natural enzyme counterparts presumably due to the lack of stable tertiary fold. We hypothesized that assembling these peptides along with simple hydrophobic pockets, mimicking enzyme active sites, could enhance the catalytic activity. Here we fused the sequence of catalytic peptide CP4, capable of protease and esterase-like activities, into a short amyloidogenic peptide fragment of Aβ. When the fused CP4-Aβ construct assembled into antiparallel β- sheets and amyloid …

From Mollusks To Medicine: A Venomics Approach For The Discovery And Characterization Of Therapeutics From Terebridae Peptide Toxins, Aida Verdes, Prachi Anand, Juliette Gorson, Stephen Jannetti, Patrick Kelly, Abba Leffler, Danny Simpson, Girish Ramrattan, Mandë Holford

Publications and Research

Animal venoms comprise a diversity of peptide toxins that manipulate molecular targets such as ion channels and receptors, making venom peptides attractive candidates for the development of therapeutics to benefit human health. However, identifying bioactive venom peptides remains a significant challenge. In this review we describe our particular venomics strategy for the discovery, characterization, and optimization of Terebridae venom peptides, teretoxins. Our strategy reflects the scientific path from mollusks to medicine in an integrative sequential approach with the following steps: (1) delimitation of venomous Terebridae lineages through taxonomic and phylogenetic analyses; (2) identification and classification of putative teretoxins through omics …

Integrated Systems Biology Analysis Of Transcriptomes Reveals Candidate Genes For Acidity Control In Developing Fruits Of Sweet Orange (Citrus Sinensis L. Osbeck), Dingquang Huang, Yihong Zhao, Minghao Cao, Liang Qiao, Zhi-Liang Zheng

Publications and Research

Organic acids, such as citrate and malate, are important contributors for the sensory traits of fleshy fruits. Although their biosynthesis has been illustrated, regulatory mechanisms of acid accumulation remain to be dissected. To provide transcriptional architecture and identify candidate genes for citrate accumulation in fruits, we have selected for transcriptome analysis four varieties of sweet orange (Citrus sinensis L. Osbeck) with varying fruit acidity, Succari (acidless), Bingtang (low acid), and Newhall and Xinhui (normal acid). Fruits of these varieties at 45 days post anthesis (DPA), which corresponds to Stage I (cell division), had similar acidity, but they displayed differential acid …

Discovery And Characterisation Of A Novel Toxin From Dendroaspis Angusticeps, Named Tx7335, That Activates The Potassium Channel Kcsa, Ivan O. Rivera-Torres, Tony B. Jin, Martine Cadene, Brian T. Chait, Sébastien F. Poget

Publications and Research

Due to their central role in essential physiological processes, potassium channels are common targets for animal toxins. These toxins in turn are of great value as tools for studying channel function and as lead compounds for drug development. Here, we used a direct toxin pull-down assay with immobilised KcsA potassium channel to isolate a novel KcsA-binding toxin (called Tx7335) from eastern green mamba snake (Dendroaspis angusticeps) venom. Sequencing of the toxin by Edman degradation and mass spectrometry revealed a 63 amino acid residue peptide with 4 disulphide bonds that belongs to the three-finger toxin family, but with a unique modification …

Engineered Protein Polymer-Gold Nanoparticle Hybrid Materials For Small Molecule Delivery, Min Dai, Ja Frezzo, E Sharma, R Chen, N Singh, C Yuvienco, E Caglar, S Xiao, A Saxena, Jk Montclare

Publications and Research

We have fabricated protein polymer-gold nanoparticle (P-GNP) nanocomposites that exhibit enhanced binding and delivery properties of the small hydrophobic molecule drug, curcumin, to the model breast cancer cell line, MCF-7. These hybrid biomaterials are constructed via in situ GNP templated-synthesis with genetically engineered histidine tags. The P-GNP nanocomposites exhibit enhanced small molecule loading, sustained release and increased uptake by MCF-7 cells. When compared to the proteins polymers alone, the P-GNPs demonstrate a greater than 7-fold increase in curcumin binding, a nearly 50% slower release profile and more than 2-fold increase in cellular uptake of curcumin. These results suggest that P-GNP …

Site-Specifically Labeled Immunoconjugates For Molecular Imaging—Part 1: Cysteine Residues And Glycans, Pierre Adumeau, Sai Kiran Sharma, Colleen Brent, Brian M. Zeglis

Publications and Research

Due to their remarkable selectivity and specificity for cancer biomarkers, immunoconjugates have emerged as extremely promising vectors for the delivery of diagnostic radioisotopes and fluorophores to malignant tissues. Paradoxically, however, these tools for precision medicine are synthesized in a remarkably imprecise way. Indeed, the vast majority of immunoconjugates are created via the random conjugation of bifunctional probes (e.g., DOTA-NCS) to amino acids within the antibody (e.g., lysines). Yet antibodies have multiple copies of these residues throughout their macromolecular structure, making control over the location of the conjugation reaction impossible. This lack of site specificity can lead to the formation of …

Characterization Of Fluorescent Proteins For Three- And Four-Color Live-Cell Imaging In S. Cerevisiae, Ryo Higuchi-Sanabria, Enrique J. Garcia, Delia Tomoiaga, Emilia L. Munteanu, Paul Feinstein, Liza A. Pon

Publications and Research

Saccharomyces cerevisiae are widely used for imaging fluorescently tagged protein fusions. Fluorescent proteins can easily be inserted into yeast genes at their chromosomal locus, by homologous recombination, for expression of tagged proteins at endogenous levels. This is especially useful for incorporation of multiple fluorescent protein fusions into a single strain, which can be challenging in organisms where genetic manipulation is more complex. However, the availability of optimal fluorescent protein combinations for 3-color imaging is limited. Here, we have characterized a combination of fluorescent proteins, mTFP1/mCitrine/ mCherry for multicolor live cell imaging in S. cerevisiae. This combination can be used with …