Biochemistry, Biophysics, and Structural Biology Commons^™

Targeting Pathogenic Lafora Bodies In Lafora Disease Using An Antibody-Enzyme Fusion, M. Kathryn Brewer, Annette M. Uittenbogaard, Grant L. Austin, Dyann M. Segvich, Anna Depaoli-Roach, Peter J. Roach, John J. Mccarthy, Zoe R. Simmons, Jason A. Brandon, Zhengqiu Zhou, Jill Zeller, Lyndsay E. A. Young, Ramon C. Sun, James R. Pauly, Nadine M. Aziz, Bradley L. Hodges, Tracy R. Mcknight, Dustin D. Armstrong, Matthew S. Gentry

Molecular and Cellular Biochemistry Faculty Publications

Lafora disease (LD) is a fatal childhood epilepsy caused by recessive mutations in either the EPM2A or EPM2B gene. A hallmark of LD is the intracellular accumulation of insoluble polysaccharide deposits known as Lafora bodies (LBs) in the brain and other tissues. In LD mouse models, genetic reduction of glycogen synthesis eliminates LB formation and rescues the neurological phenotype. Therefore, LBs have become a therapeutic target for ameliorating LD. Herein, we demonstrate that human pancreatic α-amylase degrades LBs. We fused this amylase to a cell-penetrating antibody fragment, and this antibody-enzyme fusion (VAL-0417) degrades LBs in vitro and dramatically reduces LB …

Bamorc: A Software Package For Accurate And Robust 13C Reference Correction Of Protein Nmr Spectra, Xi Chen, Andrey Smelter, Hunter N. B. Moseley

Molecular and Cellular Biochemistry Faculty Publications

We describe Bayesian Model Optimized Reference Correction (BaMORC), a software package that performs ¹³C chemical shifts reference correction for either assigned or unassigned peak lists derived from protein NMR spectra. BaMORC provides an intuitive command line interface that allows non-nuclear magnetic resonance (NMR) experts to detect and correct ¹³C chemical shift referencing errors of unassigned peak lists at the very beginning of NMR data analysis, further lowering the bar of expertise required for effective protein NMR analysis. Furthermore, BaMORC provides an application programming interface for integration into sophisticated protein NMR data analysis pipelines, both before and after the …

Discovery Of Glycerol Phosphate Modification On Streptococcal Rhamnose Polysaccharides., Rebecca J Edgar, Vincent P Van Hensbergen, Alessandro Ruda, Andrew G Turner, Pan Deng, Yoann Le Breton, Najib M El-Sayed, Ashton T Belew, Kevin S Mciver, Alastair G Mcewan, Andrew J Morris, Gérard Lambeau, Mark J Walker, Jeffrey S. Rush, Konstantin V Korotkov, Göran Widmalm, Nina M Van Sorge, Natalia Korotkova

Molecular and Cellular Biochemistry Faculty Publications

Cell wall glycopolymers on the surface of Gram-positive bacteria are fundamental to bacterial physiology and infection biology. Here we identify gacH, a gene in the Streptococcus pyogenes group A carbohydrate (GAC) biosynthetic cluster, in two independent transposon library screens for its ability to confer resistance to zinc and susceptibility to the bactericidal enzyme human group IIA-secreted phospholipase A

Semisynthetic Aurones Inhibit Tubulin Polymerization At The Colchicine-Binding Site And Repress Pc-3 Tumor Xenografts In Nude Mice And Myc-Induced T-All In Zebrafish, Yanqi Xie, Liliia M. Kril, Tianxin Yu, Wen Zhang, Mykhaylo S. Frasinyuk, Svitlana P. Bondarenko, Kostyantyn M. Kondratyuk, Elizabeth Hausman, Zachary M. Martin, Przemyslaw P. Wyrebek, Xifu Liu, Agripina G. Deaciuc, Linda P. Dwoskin, Jing Chen, Haining Zhu, Chang-Guo Zhan, Vitaliy M. Sviripa, Jessica S. Blackburn, David S. Watt, Chunming Liu

Molecular and Cellular Biochemistry Faculty Publications

Structure-activity relationships (SAR) in the aurone pharmacophore identified heterocyclic variants of the (Z)-2-benzylidene-6-hydroxybenzofuran-3(2H)-one scaffold that possessed low nanomolar in vitro potency in cell proliferation assays using various cancer cell lines, in vivo potency in prostate cancer PC-3 xenograft and zebrafish models, selectivity for the colchicine-binding site on tubulin, and absence of appreciable toxicity. Among the leading, biologically active analogs were (Z)-2-((2-((1-ethyl-5-methoxy-1H-indol-3-yl)methylene)-3-oxo-2,3-dihydrobenzofuran-6-yl)oxy)acetonitrile (5a) and (Z)-6-((2,6-dichlorobenzyl)oxy)-2-(pyridin-4-ylmethylene)benzofuran-3(2H)-one (5b) that inhibited in vitro PC-3 prostate cancer cell proliferation with IC₅₀ values below 100 nM. A xenograft study in nude mice using …

Transcriptional Regulation Factors Of The Human Mitochondrial Aspartate/Glutamate Carrier Gene, Isoform 2 (Slc25a13): Usf1 As Basal Factor And Foxa2 As Activator In Liver Cells, Paolo Convertini, Simona Todisco, Francesco De Santis, Ilaria Pappalardo, Dominga Iacobazzi, Maria Antonietta Castiglione Morelli, Yvonne N. Fondufe-Mittendorf, Giuseppe Martelli, Ferdinando Palmieri, Vittoria Infantino

Molecular and Cellular Biochemistry Faculty Publications

Mitochondrial carriers catalyse the translocation of numerous metabolites across the inner mitochondrial membrane, playing a key role in different cell functions. For this reason, mitochondrial carrier gene expression needs tight regulation. The human SLC25A13 gene, encoding for the mitochondrial aspartate/glutamate carrier isoform 2 (AGC2), catalyses the electrogenic exchange of aspartate for glutamate plus a proton, thus taking part in many metabolic processes including the malate-aspartate shuttle. By the luciferase (LUC) activity of promoter deletion constructs we identified the putative promoter region, comprising the proximal promoter (−442 bp/−19 bp), as well as an enhancer region (−968 bp/−768 bp). Furthermore, with different …

Parp1 Is A Versatile Factor In The Regulation Of Mrna Stability And Decay, Elena A. Matveeva, Lein F. Mathbout, Yvonne N. Fondufe-Mittendorf

Molecular and Cellular Biochemistry Faculty Publications

PARP1 is an abundant nuclear protein with many pleiotropic functions involved in epigenetic and transcriptional controls. Abundance of mRNA depends on the balance between synthesis and decay of a particular transcript. PARP1 binds RNA and its depletion results in increased expression of genes involved in nonsense-mediated decay, suggesting that PARP1 might be involved in mRNA stability. This is of interest considering RNA binding proteins play key roles in post-transcriptional processes in all eukaryotes. We tested the direct impact of PARP1 and PARylation on mRNA stability and decay. By measuring the half-lives of two PARP1-mRNA targets we found that the half-lives …

Stress-Induced Epinephrine Enhances Lactate Dehydrogenase A And Promotes Breast Cancer Stem-Like Cells, Bai Cui, Yuanyuan Luo, Pengfei Tian, Fei Peng, Jinxin Lu, Yongliang Yang, Qitong Su, Bing Liu, Jiachuan Yu, Xi Luo, Liu Yin, Wei Cheng, Fan An, Bin He, Dapeng Liang, Sijin Wu, Peng Chu, Luyao Song, Xinyu Liu, Huandong Luo, Binhua P. Zhou

Molecular and Cellular Biochemistry Faculty Publications

Chronic stress triggers activation of the sympathetic nervous system and drives malignancy. Using an immunodeficient murine system, we showed that chronic stress–induced epinephrine promoted breast cancer stem-like properties via lactate dehydrogenase A–dependent (LDHA-dependent) metabolic rewiring. Chronic stress–induced epinephrine activated LDHA to generate lactate, and the adjusted pH directed USP28-mediated deubiquitination and stabilization of MYC. The SLUG promoter was then activated by MYC, which promoted development of breast cancer stem-like traits. Using a drug screen that targeted LDHA, we found that a chronic stress–induced cancer stem-like phenotype could be reversed by vitamin C. These findings demonstrated the critical importance of psychological …

Coupling Of Parp1-Mediated Chromatin Structural Changes To Transcriptional Rna Polymerase Ii Elongation And Cotranscriptional Splicing, Elena A. Matveeva, Qamar M. H. Al-Tinawi, Eric C. Rouchka, Yvonne N. Fondufe-Mittendorf

Molecular and Cellular Biochemistry Faculty Publications

Background: Recently, we showed that PARP1 is involved in cotranscriptional splicing, possibly by bridging chromatin to RNA and recruiting splicing factors. It also can influence alternative splicing decisions through the regulation of RNAPII elongation. In this study, we investigated the effect of PARP1-mediated chromatin changes on RNAPII movement, during transcription and alternative splicing.

Results: We show that RNAPII pauses at PARP1–chromatin structures within the gene body. Knockdown of PARP1 abolishes this RNAPII pausing, suggesting that PARP1 may regulate RNAPII elongation. Additionally, PARP1 alters nucleosome deposition and histone post-translational modifications at specific exon–intron boundaries, thereby affecting RNAPII movement. Lastly, genome-wide analyses …

Clinical Features, Survival And Prognostic Factors Of Glycogen-Rich Clear Cell Carcinoma (Grcc) Of The Breast In The U.S. Population, Zhengqiu Zhou, Connor J. Kinslow, Hanina Hibshoosh, Hua Guo, Simon K. Cheng, Chunyan He, Matthew S. Gentry, Ramon C. Sun

Molecular and Cellular Biochemistry Faculty Publications

The World Health Organization (WHO) defines glycogen-rich clear cell carcinoma (GRCC) of the breast as a carcinoma with glycogen accumulation in more than 90% of its tumor cells. Due to the rarity of this disease, its reported survival and clinical associations have been inconsistent due to reliance on case reports and limited case series. As a result, the prognostic implication of this cancer subtype remains unclear. Using the U.S. Surveillance, Epidemiology, and End Results (SEER) program database, we compared the incidence, demographics and prognostic factors of 155 cases of GRCC of the breast to 1,251,584 cases of other (non-GRCC) breast …

Immunization Of Alpacas (Lama Pacos) With Protein Antigens And Production Of Antigen-Specific Single Domain Antibodies, K. Martin Chow, Sidney W. Whiteheart, Jeffrey R. Smiley, Savita Sharma, Kathy Boaz, Meggie J. Coleman, Alvina Maynard, Louis B. Hersh, Craig W. Vander Kooi

Molecular and Cellular Biochemistry Faculty Publications

In this manuscript, a method for the immunization of alpaca and the use of molecular biology methods to produce antigen-specific single domain antibodies is described and demonstrated. Camelids, such as alpacas and llamas, have become a valuable resource for biomedical research since they produce a novel type of heavy chain-only antibody which can be used to produce single domain antibodies. Because the immune system is highly flexible, single domain antibodies can be made to many different protein antigens, and even different conformations of the antigen, with a very high degree of specificity. These features, among others, make single domain antibodies …

Itch Nuclear Translocation And H1.2 Polyubiquitination Negatively Regulate The Dna Damage Response, Lufen Chang, Lei Shen, Hu Zhou, Jing Gao, Hangyi Pan, Li Zheng, Brian Armstrong, Yang Peng, Guang Peng, Binhua P. Zhou, Steven T. Rosen, Binghui Shen

Molecular and Cellular Biochemistry Faculty Publications

The downregulation of the DNA damage response (DDR) enables aggressive tumors to achieve uncontrolled proliferation against replication stress, but the mechanisms underlying this process in tumors are relatively complex. Here, we demonstrate a mechanism through which a distinct E3 ubiquitin ligase, ITCH, modulates DDR machinery in triple-negative breast cancer (TNBC). We found that expression of a nuclear form of ITCH was significantly increased in human TNBC cell lines and tumor specimens. Phosphorylation of ITCH at Ser257 by AKT led to the nuclear localization of ITCH and ubiquitination of H1.2. The ITCH-mediated polyubiquitination of H1.2 suppressed RNF8/RNF168-dependent formation of 53BP1 foci, …

Targeting The Brd4/Foxo3a/Cdk6 Axis Sensitizes Akt Inhibition In Luminal Breast Cancer, Jingyi Liu, Weijie Guo, Zhibing Duan, Lei Zeng, Yadi Wu, Yule Chen, Fang Tai, Yifan Wang, Yiwei Lin, Qiang Zhang, Yanling He, Jiong Deng, Rachel L. Stewart, Chi Wang, Pengnian Charles Lin, Saghi Ghaffari, B. Mark Evers, Suling Liu, Ming-Ming Zhou, Binhua P. Zhou, Jian Shi

Molecular and Cellular Biochemistry Faculty Publications

BRD4 assembles transcriptional machinery at gene super-enhancer regions and governs the expression of genes that are critical for cancer progression. However, it remains unclear whether BRD4-mediated gene transcription is required for tumor cells to develop drug resistance. Our data show that prolonged treatment of luminal breast cancer cells with AKT inhibitors induces FOXO3a dephosphorylation, nuclear translocation, and disrupts its association with SirT6, eventually leading to FOXO3a acetylation as well as BRD4 recognition. Acetylated FOXO3a recognizes the BD2 domain of BRD4, recruits the BRD4/RNAPII complex to the CDK6 gene promoter, and induces its transcription. Pharmacological inhibition of either BRD4/FOXO3a association or …

Mitochondrial Metabolism In Major Neurological Diseases, Zhengqiu Zhou, Grant L. Austin, Lyndsay E. A. Young, Lance A. Johnson, Ramon Sun

Molecular and Cellular Biochemistry Faculty Publications

Mitochondria are bilayer sub-cellular organelles that are an integral part of normal cellular physiology. They are responsible for producing the majority of a cell’s ATP, thus supplying energy for a variety of key cellular processes, especially in the brain. Although energy production is a key aspect of mitochondrial metabolism, its role extends far beyond energy production to cell signaling and epigenetic regulation–functions that contribute to cellular proliferation, differentiation, apoptosis, migration, and autophagy. Recent research on neurological disorders suggest a major metabolic component in disease pathophysiology, and mitochondria have been shown to be in the center of metabolic dysregulation and possibly …

Snare-Dependent Membrane Fusion Initiates Α-Granule Matrix Decondensation In Mouse Platelets, Irina D. Pokrovskaya, Smita Joshi, Michael Tobin, Rohan Desai, Maria A. Aronova, Jeffrey A. Kamykowski, Guofeng Zhang, Sidney W. Whiteheart, Richard D. Leapman, Brian Storrie

Molecular and Cellular Biochemistry Faculty Publications

Platelet α-granule cargo release is fundamental to both hemostasis and thrombosis. Granule matrix hydration is a key regulated step in this process, yet its mechanism is poorly understood. In endothelial cells, there is evidence for 2 modes of cargo release: a jack-in-the-box mechanism of hydration-dependent protein phase transitions and an actin-driven granule constriction/extrusion mechanism. The third alternative considered is a prefusion, channel-mediated granule swelling, analogous to the membrane “ballooning” seen in procoagulant platelets. Using thrombin-stimulated platelets from a set of secretion-deficient, soluble N-ethylmaleimide factor attachment protein receptor (SNARE) mutant mice and various ultrastructural approaches, we tested predictions of these …

Alterations In Platelet Secretion Differentially Affect Thrombosis And Hemostasis, Smita Joshi, Meenakshi Banerjee, Jinchao Zhang, Akhil Kesaraju, Irina D. Pokrovskaya, Brian Storrie, Sidney W. Whiteheart

Molecular and Cellular Biochemistry Faculty Publications

We genetically manipulated the major platelet vesicle-associated membrane proteins (VAMP2, VAMP3, and VAMP8) to create mice with varying degrees of disrupted platelet secretion. As previously shown, loss of VAMP8 reduced granule secretion, and this defect was exacerbated by further deletion of VAMP2 and VAMP3. VAMP2^Δ3^Δ8^−/− platelets also had reduced VAMP7. Loss of VAMP2 and VAMP3 (VAMP2^Δ3^Δ) had a minimal impact on secretion when VAMP7 and VAMP8 were present. Integrin αIIbβ3 activation and aggregation were not affected, although spreading was reduced in VAMP2^Δ3^Δ8^−/− platelets. Using these mice …

Structure Of The Mouse Trpc4 Ion Channel, Jingjing Duan, Jian Li, Bo Zeng, Gui-Lan Chen, Xiaogang Peng, Yixing Zhang, Jianbin Wang, David E. Clapham, Zongli Li, Jin Zhang

Molecular and Cellular Biochemistry Faculty Publications

Members of the transient receptor potential (TRP) ion channels conduct cations into cells. They mediate functions ranging from neuronally mediated hot and cold sensation to intracellular organellar and primary ciliary signaling. Here we report a cryo-electron microscopy (cryo-EM) structure of TRPC4 in its unliganded (apo) state to an overall resolution of 3.3 Å. The structure reveals a unique architecture with a long pore loop stabilized by a disulfide bond. Beyond the shared tetrameric six-transmembrane fold, the TRPC4 structure deviates from other TRP channels with a unique cytosolic domain. This unique cytosolic N-terminal domain forms extensive aromatic contacts with the TRP …

Bioprospecting Deep-Sea Actinobacteria For Novel Anti-Infective Natural Products, Dongbo Xu, Linna Han, Chunhui Li, Qi Cao, Duolong Zhu, Nolan H. Barrett, Dedra Harmody, Jing Chen, Haining Zhu, Peter J. Mccarthy, Xingmin Sun, Guojun Wang

Molecular and Cellular Biochemistry Faculty Publications

The global prevalence of drug resistance has created an urgent need for the discovery of novel anti-infective drugs. The major source of antibiotics in current clinical practice is terrestrial actinobacteria; the less-exploited deep-sea actinobacteria may serve as an unprecedented source of novel natural products. In this study, we evaluated 50 actinobacteria strains derived from diverse deep water sponges and environmental niches for their anti-microbial activities against a panel of pathogens including Candida albicans, Clostridium difficile, Staphylococcus aureus, and methicillin-resistant S. aureus (MRSA), and Pseudomonas aeruginosa. More than half of the tested strains (27) were identified as …

Transmembrane Domains Of Highly Pathogenic Viral Fusion Proteins Exhibit Trimeric Association In Vitro, Stacy R. Webb, Stacy E. Smith, Michael G. Fried, Rebecca Ellis Dutch

Molecular and Cellular Biochemistry Faculty Publications

Enveloped viruses require viral fusion proteins to promote fusion of the viral envelope with a target cell membrane. To drive fusion, these proteins undergo large conformational changes that must occur at the right place and at the right time. Understanding the elements which control the stability of the prefusion state and the initiation of conformational changes is key to understanding the function of these important proteins. The construction of mutations in the fusion protein transmembrane domains (TMDs) or the replacement of these domains with lipid anchors has implicated the TMD in the fusion process. However, the structural and molecular details …

Structure Of Full-Length Human Trpm4, Jingjing Duan, Zongli Li, Jian Li, Ana Santa-Cruz, Silvia Sanchez-Martinez, Jin Zhang, David E. Clapham

Molecular and Cellular Biochemistry Faculty Publications

Transient receptor potential melastatin subfamily member 4 (TRPM4) is a widely distributed, calcium-activated, monovalent-selective cation channel. Mutations in human TRPM4 (hTRPM4) result in progressive familial heart block. Here, we report the electron cryomicroscopy structure of hTRPM4 in a closed, Na⁺-bound, apo state at pH 7.5 to an overall resolution of 3.7 Å. Five partially hydrated sodium ions are proposed to occupy the center of the conduction pore and the entrance to the coiled-coil domain. We identify an upper gate in the selectivity filter and a lower gate at the entrance to the cytoplasmic coiled-coil domain. Intramolecular interactions exist …

Lafora Disease Offers A Unique Window Into Neuronal Glycogen Metabolism, Matthew S. Gentry, Joan J. Guinovart, Berge A. Minassian, Peter J. Roach, Jose M. Serratosa

Molecular and Cellular Biochemistry Faculty Publications

Lafora disease (LD) is a fatal, autosomal recessive, glycogen-storage disorder that manifests as severe epilepsy. LD results from mutations in the gene encoding either the glycogen phosphatase laforin or the E3 ubiquitin ligase malin. Individuals with LD develop cytoplasmic, aberrant glycogen inclusions in nearly all tissues that more closely resemble plant starch than human glycogen. This Minireview discusses the unique window into glycogen metabolism that LD research offers. It also highlights recent discoveries, including that glycogen contains covalently bound phosphate and that neurons synthesize glycogen and express both glycogen synthase and glycogen phosphorylase.

Insulin-Degrading Enzyme Is Not Secreted From Cultured Cells, Eun Suk Song, David W. Rodgers, Louis Hersh

Molecular and Cellular Biochemistry Faculty Publications

Insulin-degrading enzyme (IDE) functions in the catabolism of bioactive peptides. Established roles include degrading insulin and the amyloid beta peptide (Aβ), linking it to diabetes and Alzheimer’s disease. IDE is primarily located in the cytosol, and a longstanding question is how it gains access to its peptide substrates. Reports suggest that IDE secreted by an unconventional pathway participates in extracellular hydrolysis of insulin and Aβ. We find that IDE release from cultured HEK-293 or BV-2 cells represents only ~1% of total cellular IDE, far less than has been reported previously. Importantly, lactate dehydrogenase (LDH) and other cytosolic enzymes are released …

Kruppel-Like Factor 4-Dependent Staufen1-Mediated Mrna Decay Regulates Cortical Neurogenesis, Byoung-San Moon, Jinlun Bai, Mingyang Cai, Chunming Liu, Jiandang Shi, Wange Lu

Molecular and Cellular Biochemistry Faculty Publications

Kruppel-like factor 4 (Klf4) is a zinc-finger-containing protein that plays a critical role in diverse cellular physiology. While most of these functions attribute to its role as a transcription factor, it is postulated that Klf4 may play a role other than transcriptional regulation. Here we demonstrate that Klf4 loss in neural progenitor cells (NPCs) leads to increased neurogenesis and reduced self-renewal in mice. In addition, Klf4 interacts with RNA-binding protein Staufen1 (Stau1) and RNA helicase Ddx5/17. They function together as a complex to maintain NPC self-renewal. We report that Klf4 promotes Stau1 recruitment to the 3′-untranslated region of neurogenesis-associated mRNAs, …

Amyloid-Beta Solubility In The Treatment Of Alzheimer's Disease, Michael Paul Murphy

Molecular and Cellular Biochemistry Faculty Publications

No abstract provided.

Dynamic Cycling Of T-Snare Acylation Regulates Platelet Exocytosis, Jinchao Zhang, Yunjie Huang, Jing Chen, Haining Zhu, Sidney W. Whiteheart

Molecular and Cellular Biochemistry Faculty Publications

Platelets regulate vascular integrity by secreting a host of molecules that promote hemostasis and its sequelae. Given the importance of platelet exocytosis, it is critical to understand how it is controlled. The t-SNAREs, SNAP-23 and syntaxin-11, lack classical transmembrane domains (TMDs), yet both are associated with platelet membranes and redistributed into cholesterol-dependent lipid rafts when platelets are activated. Using metabolic labeling and hydroxylamine (HA)/HCl treatment, we showed that both contain thioester-linked acyl groups. Mass spectrometry mapping further showed that syntaxin-11 was modified on cysteine 275, 279, 280, 282, 283, and 285, and SNAP-23 was modified on cysteine 79, 80, 83, …

Selective Inhibition Of Ctcf Binding By Ias Directs Tet-Mediated Reprogramming Of 5-Hydroxymethylation Patterns In Ias-Transformed Cells, Matthew Rea, Tyler Gripshover, Yvonne N. Fondufe-Mittendorf

Molecular and Cellular Biochemistry Faculty Publications

Methylation at cytosine (5mC) is a fundamental epigenetic DNA modification recently associated with iAs-mediated carcinogenesis. In contrast, the role of 5-hydroxymethylcytosine (5hmC), the oxidation product of 5mC in iAs-mediated carcinogenesis is unknown. Here we assess the hydroxymethylome in iAs-transformed cells, showing that dynamic modulation of hydroxymethylated DNA is associated with specific transcriptional networks. Moreover, this pathologic iAs-mediated carcinogenesis is characterized by a shift toward a higher hydroxymethylation pattern genome-wide. At specific promoters, hydroxymethylation correlated with increased gene expression. Furthermore, this increase in hydroxymethylation occurs concurrently with an upregulation of ten-eleven translocation (TET) enzymes that oxidize 5-methylcytosine (5mC) in DNA. To …

Cellubrevin/Vesicle-Associated Membrane Protein-3–Mediated Endocytosis And Trafficking Regulate Platelet Functions, Meenakshi Banerjee, Smita Joshi, Jinchao Zhang, Carole L. Moncman, Shilpi Yadav, Beth A. Bouchard, Brian Storrie, Sidney W. Whiteheart

Molecular and Cellular Biochemistry Faculty Publications

Endocytosis is key to fibrinogen (Fg) uptake, trafficking of integrins (αIIbβ₃, α_vβ₃), and purinergic receptors (P2Y₁, P2Y₁₂), and thus normal platelet function. However, the molecular machinery required and possible trafficking routes are still ill-defined. To further identify elements of the platelet endocytic machinery, we examined the role of a vesicle-residing, soluble N-ethylmaleimide factor attachment protein receptor (v-SNARE) called cellubrevin/vesicle-associated membrane protein-3 (VAMP-3) in platelet function. Although not required for normal platelet exocytosis or hemostasis, VAMP-3^−/− mice had less platelet-associated Fg, indicating a defect in Fg uptake/storage. Other granule …

Serine-Dependent Sphingolipid Synthesis Is A Metabolic Liability Of Aneuploid Cells, Sunyoung Hwang, H. Tobias Gustafsson, Ciara O’Sullivan, Gianna Bisceglia, Xinhe Huang, Christian Klose, Andrej Schevchenko, Robert C. Dickson, Paola Cavaliere, Noah Dephoure, Eduardo M. Torres

Molecular and Cellular Biochemistry Faculty Publications

Aneuploidy disrupts cellular homeostasis. However, the molecular mechanisms underlying the physiological responses and adaptation to aneuploidy are not well understood. Deciphering these mechanisms is important because aneuploidy is associated with diseases, including intellectual disability and cancer. Although tumors and mammalian aneuploid cells, including several cancer cell lines, show altered levels of sphingolipids, the role of sphingolipids in aneuploidy remains unknown. Here, we show that ceramides and long-chain bases, sphingolipid molecules that slow proliferation and promote survival, are increased by aneuploidy. Sphingolipid levels are tightly linked to serine synthesis, and inhibiting either serine or sphingolipid synthesis can specifically impair the fitness …

Lipophosphoglycan Polymorphisms Do Not Affect Leishmania Amazonensis Development In The Permissive Vectors Lutzomyia Migonei And Lutzomyia Longipalpis, Paula M. Nogueira, Agna C. Guimarães, Rafael R. Assis, Jovana Sadlova, Jitka Myskova, Katerina Pruzinova, Jana Hlavackova, Salvatore J. Turco, Ana C. Torrecilhas, Petr Volf, Rodrigo P. Soares

Molecular and Cellular Biochemistry Faculty Publications

Background: Lipophosphoglycan (LPG) is a dominant surface molecule of Leishmaniapromastigotes. Its species-specific polymorphisms are found mainly in the sugars that branch off the conserved Gal(β1,4)Man(α1)-PO₄ backbone of repeat units. Leishmania amazonensis is one of the most important species causing human cutaneous leishmaniasis in the New World. Here, we describe LPG intraspecific polymorphisms in two Le. amazonensis reference strains and their role during the development in three sand fly species.

Results: Strains isolated from Lutzomyia flaviscutellata (PH8) and from a human patient (Josefa) displayed structural polymorphism in the LPG repeat units, possessing side chains with 1 and 2 β-glucose …

Structural And Functional Insights Into The Role Of Bamd And Bame Within The Β-Barrel Assembly Machinery In Neisseria Gonorrhoeae, Aleksandra E. Sikora, Igor H. Wierzbicki, Ryszard A. Zielke, Rachael F. Ryner, Konstantin V. Korotkov, Susan K. Buchanan, Nicholas Noinaj

Molecular and Cellular Biochemistry Faculty Publications

The β-barrel assembly machinery (BAM) is a conserved multicomponent protein complex responsible for the biogenesis of β-barrel outer membrane proteins (OMPs) in Gram-negative bacteria. Given its role in the production of OMPs for survival and pathogenesis, BAM represents an attractive target for the development of therapeutic interventions, including drugs and vaccines against multidrug-resistant bacteria such as Neisseria gonorrhoeae. The first structure of BamA, the central component of BAM, was from N. gonorrhoeae, the etiological agent of the sexually transmitted disease gonorrhea. To aid in pharmaceutical targeting of BAM, we expanded our studies to BamD and BamE within …

Human Metapneumovirus Induces Formation Of Inclusion Bodies For Efficient Genome Replication And Transcription, Nicolás P. Cifuentes-Muñoz, Jean Branttie, Kerri Beth Slaughter, Rebecca Ellis Dutch

Molecular and Cellular Biochemistry Faculty Publications

Human metapneumovirus (HMPV) causes significant upper and lower respiratory disease in all age groups worldwide. The virus possesses a negative-sense single-stranded RNA genome of approximately 13.3 kb encapsidated by multiple copies of the nucleoprotein (N), giving rise to helical nucleocapsids. In addition, copies of the phosphoprotein (P) and the large RNA polymerase (L) decorate the viral nucleocapsids. After viral attachment, endocytosis, and fusion mediated by the viral glycoproteins, HMPV nucleocapsids are released into the cell cytoplasm. To visualize the subsequent steps of genome transcription and replication, a fluorescence in situ hybridization (FISH) protocol was established to detect different viral RNA …