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1. In Vitro Efficacy of Targeted Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols Enzymatic Digestion in a High-Fidelity Simulated Gastrointestinal Environment

Author

Kenny Castro Ochoa, Shalaka Samant, Anjie Liu, Cindy Duysburgh, Massimo Marzorati, Prashant Singh, David Hachuel, William Chey, and Thomas Wallach

Subjects
IBS, FODMAP, Fructan, Generally-Regarded-as-Safe, Diseases of the digestive system. Gastroenterology, RC799-869
Abstract

Background and Aims: Irritable bowel syndrome (IBS) is characterized by abdominal pain and changes in bowel habits. Fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) are poorly absorbed short-chain carbohydrates that may drive commensal microbial gas production, promoting abdominal pain in IBS. Low-FODMAP diet can result in symptomatic improvement in 50%–80% of IBS patients. However, this diet is not meant to be sustained long term, with concern for downstream nutrition and microbial issues. In this study, we evaluate the function of a targeted FODMAP enzymatic digestion food supplement FODMAP enzymatic digestion (FODZYME) containing a fructan-hydrolase enzyme (with significant inulinase activity) in a simulated gastrointestinal environment. Methods: Using SHIME (Simulator of the Human Intestinal Microbial Ecosystem), a multi-compartment simulator of the human gut, FODZYME dose finding assay in modeled gastrointestinal conditions assessed enzymatic ability to hydrolyze 3 g of inulin. Full intestinal modeling assessing digestion of inulin, absorption of fructose, gas production, and other measures of commensal microbial behavior was completed using 1.125 g of FODZYME. Results: After 30 minutes, 90% of the inulin was converted to fructose by 1.125 g of FODZYME. Doubling dosage showed no significant improvement in conversion, whereas a half dose decreased performance to 77.2%. Seventy percent of released fructose was absorbed during simulated small intestinal transit, with a corresponding decrease in microbial gas production, and a small decrease in butyrate and short-chain fatty acid production. Conclusion: FODZYME specifically breaks down inulin in representative gastrointestinal conditions, resulting in decreased gas production while substantially preserving short-chain fatty acid and butyrate production in the model colon. Our results suggest dietary supplementation with FODZYME would decrease intestinal FODMAP burden and gas production.

Published
2023
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2. A strategy to identify a ketoreductase that preferentially synthesizes pharmaceutically relevant (S)-alcohols using whole-cell biotransformation

Author

Saiful F. Haq, Anirudh P. Shanbhag, Subbulakshmi Karthikeyan, Imran Hassan, Kannan Thanukrishnan, Abhishek Ashok, Sunilkumar Sukumaran, S. Ramaswamy, Nagakumar Bharatham, Santanu Datta, Shalaka Samant, and Nainesh Katagihallimath

Subjects
Biotransformation, Chiral alcohol synthesis, Short chain dehydrogenase, Medium chain dehydrogenase, Ketoreductase, Microbiology, QR1-502
Abstract

Abstract Introduction Chemical industries are constantly in search of an expeditious and environmentally benign method for producing chiral synthons. Ketoreductases have been used as catalysts for enantioselective conversion of desired prochiral ketones to their corresponding alcohol. We chose reported promiscuous ketoreductases belonging to different protein families and expressed them in E. coli to evaluate their ability as whole-cell catalysts for obtaining chiral alcohol intermediates of pharmaceutical importance. Apart from establishing a method to produce high value (S)-specific alcohols that have not been evaluated before, we propose an in silico analysis procedure to predict product chirality. Results Six enzymes originating from Sulfolobus sulfotaricus, Zygosaccharomyces rouxii, Hansenula polymorpha, Corynebacterium sp. ST-10, Synechococcus sp. PCC 7942 and Bacillus sp. ECU0013 with reported efficient activity for dissimilar substrates are compared here to arrive at an optimal enzyme for the method. Whole–cell catalysis of ketone intermediates for drugs like Aprepitant, Sitagliptin and Dolastatin using E. coli over-expressing these enzymes yielded (S)-specific chiral alcohols. We explain this chiral specificity for the best-performing enzyme, i.e., Z. rouxii ketoreductase using in silico modelling and MD simulations. This rationale was applied to five additional ketones that are used in the synthesis of Crizotinib, MA-20565 (an antifungal agent), Sulopenem, Rivastigmine, Talampanel and Barnidipine and predicted the yield of (S) enantiomers. Experimental evaluation matched the in silico analysis wherein ~ 95% (S)-specific alcohol with a chemical yield of 23–79% was obtained through biotransformation. Further, the cofactor re-cycling was optimized by switching the carbon source from glucose to sorbitol that improved the chemical yield to 85–99%. Conclusions Here, we present a strategy to synthesize pharmaceutically relevant chiral alcohols by ketoreductases using a cofactor balanced whole-cell catalysis scheme that is useful for the industry. Based on the results obtained in these trials, Zygosaccharomyces rouxii ketoreductase was identified as a proficient enzyme to obtain (S)-specific alcohols from their respective ketones. The whole–cell catalyst when combined with nutrient modulation of using sorbitol as a carbon source helped obtain high enantiomeric and chemical yield.

Published
2018
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3. Nucleotide biosynthesis is critical for growth of bacteria in human blood.

Author

Shalaka Samant, Hyunwoo Lee, Mahmood Ghassemi, Juan Chen, James L Cook, Alexander S Mankin, and Alexander A Neyfakh

Subjects
Immunologic diseases. Allergy, RC581-607, Biology (General), QH301-705.5
Abstract

Proliferation of bacterial pathogens in blood represents one of the most dangerous stages of infection. Growth in blood serum depends on the ability of a pathogen to adjust metabolism to match the availability of nutrients. Although certain nutrients are scarce in blood and need to be de novo synthesized by proliferating bacteria, it is unclear which metabolic pathways are critical for bacterial growth in blood. In this study, we identified metabolic functions that are essential specifically for bacterial growth in the bloodstream. We used two principally different but complementing techniques to comprehensively identify genes that are required for the growth of Escherichia coli in human serum. A microarray-based and a dye-based mutant screening approach were independently used to screen a library of 3,985 single-gene deletion mutants in all non-essential genes of E. coli (Keio collection). A majority of the mutants identified consistently by both approaches carried a deletion of a gene involved in either the purine or pyrimidine nucleotide biosynthetic pathway and showed a 20- to 1,000-fold drop in viable cell counts as compared to wild-type E. coli after 24 h of growth in human serum. This suggests that the scarcity of nucleotide precursors, but not other nutrients, is the key limitation for bacterial growth in serum. Inactivation of nucleotide biosynthesis genes in another gram-negative pathogen, Salmonella enterica, and in the gram-positive pathogen Bacillus anthracis, prevented their growth in human serum. The growth of the mutants could be rescued by genetic complementation or by addition of appropriate nucleotide bases to human serum. Furthermore, the virulence of the B. anthracis purE mutant, defective in purine biosynthesis, was dramatically attenuated in a murine model of bacteremia. Our data indicate that de novo nucleotide biosynthesis represents the single most critical metabolic function for bacterial growth in blood and reveal the corresponding enzymes as putative antibiotic targets for the treatment of bloodstream infections.

Published
2008
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4. In-VitroEfficacy of Targeted FODMAP Enzymatic Digestion (FODZYME®) in a High-Fidelity Simulated Gastrointestinal Environment

Author

Kenny Castro Ochoa, Shalaka Samant, Anjie Liu, Cindy Duysburgh, Massimo Marzorati, Prashant Singh, David Hachuel, William Chey, and Thomas Wallach

Abstract

IntroductionIrritable bowel syndrome (IBS) is characterized by abdominal pain and changes in bowel habits. FODMAPs are poorly absorbed short-chain carbohydrates that may drive commensal microbial gas production, promoting abdominal pain in IBS. Low-FODMAP diet can result in symptomatic improvement in 50-80% of IBS patients. However, this diet is not meant to be sustained long term, with concern for downstream nutrition and microbial issues. In this study, we evaluate the function of a targeted FODMAP enzymatic digestion food supplement FODZYME® containing an fructan hydrolase enzyme in a simulated gastrointestinal environment.MethodsUsing SHIME®, a multi-compartment simulator of the human gut, FODZYME® dose finding assay in modeled gastrointestinal conditions assessed enzymatic ability to hydrolyze 3 g of inulin. Full intestinal modeling assessing digestion of inulin, absorption of fructose, gas production and other measures of commensal microbial behavior was completed using 1.125 g of FODZYME®.ResultsAfter 30 minutes, 90% of the inulin was converted to fructose by 1.125 g of FODZYME®.Doubling dosage showed no significant improvement in conversion, whereas a half dose decreased performance to 77.2%. 70% of released fructose was absorbed during simulated small intestinal transit, with a corresponding decrease in microbial gas production, and a small decrease in butyrate and short chain fatty acid (SCFA) production.DiscussionFODZYME® specifically breaks down inulin in representative gastrointestinal conditions, resulting in decreased gas production while substantially preserving SCFA and butyrate production in the model colon. Our results suggest dietary supplementation with FODZYME® would decrease intestinal FODMAP burden and gas production.

Published
2022
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6. Adaptation of Lactobacillus acidophilus to Thermal Stress Yields a Thermotolerant Variant Which Also Exhibits Improved Survival at pH 2

Author

Shalaka Samant, Sunilkumar Sukumaran, Saiful F. Haq, and Sonia Kulkarni

Subjects
Thermotolerance, 0301 basic medicine, Hot Temperature, 030106 microbiology, Improved survival, Biology, Microbiology, law.invention, 03 medical and health sciences, Probiotic, Lactobacillus acidophilus, law, Molecular Biology, Microbial Viability, Strain (chemistry), Probiotics, Production cost, Hydrogen-Ion Concentration, Adaptation, Physiological, Temperature stress, Cross-tolerance, Molecular Medicine, Adaptation, Acids
Abstract

Loss in probiotic viability upon exposure to stressful storage and transport conditions has plagued the probiotic market worldwide. Lactobacillus acidophilus is an important probiotic that is added to various functional foods. It is known to be fairly labile and susceptible to temperature variations that it encounters during processing and storage which increases production cost. It has been repeatedly demonstrated that pre-exposure to sub-lethal doses of stress, particularly, temperature and pH, leads to improved survival of various probiotics when they subsequently encounter the same stress of a much greater magnitude. Attempts to adapt L. acidophilus to temperatures as high as 65 °C to arrive at a thermotolerant variant have not been reported previously. To improve viability at elevated temperatures, we gradually adapted the L. acidophilus NCFM strain to survival at 65 °C for 40 min. Following adaptation, the variant showed a 2-log greater survival compared to wild-type at 65 °C. Interestingly, this thermotolerant variant also demonstrated a 2-log greater stability compared to wild-type at pH 2.0. The improved pH and temperature stress tolerance exhibited by this variant remained unaltered even when the strain was lyophilized. Moreover, the thermotolerant variant demonstrated improved stability compared to wild-type when stored for up to a week at 37 and 42 °C. Probiotic properties of the variant such as adherence to epithelial cells and antibacterial activity remained unaltered. This strain can potentially help address the issue of significant loss in viable cell counts of L. acidophilus which is typically encountered during probiotic manufacture and storage.

Published
2017
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7. Heterozygous Variants in KMT2E Cause a Spectrum of Neurodevelopmental Disorders and Epilepsy

Author

Anne H. O’Donnell-Luria, Lynn S. Pais, Víctor Faundes, Jordan C. Wood, Abigail Sveden, Victor Luria, Rami Abou Jamra, Andrea Accogli, Kimberly Amburgey, Britt Marie Anderlid, Silvia Azzarello-Burri, Alice A. Basinger, Claudia Bianchini, Lynne M. Bird, Rebecca Buchert, Wilfrid Carre, Sophia Ceulemans, Perrine Charles, Helen Cox, Lisa Culliton, Aurora Currò, Florence Demurger, James J. Dowling, Benedicte Duban-Bedu, Christèle Dubourg, Saga Elise Eiset, Luis F. Escobar, Alessandra Ferrarini, Tobias B. Haack, Mona Hashim, Solveig Heide, Katherine L. Helbig, Ingo Helbig, Raul Heredia, Delphine Héron, Bertrand Isidor, Amy R. Jonasson, Pascal Joset, Boris Keren, Fernando Kok, Hester Y. Kroes, Alinoë Lavillaureix, Xin Lu, Saskia M. Maas, Gustavo H.B. Maegawa, Carlo L.M. Marcelis, Paul R. Mark, Marcelo R. Masruha, Heather M. McLaughlin, Kirsty McWalter, Esther U. Melchinger, Saadet Mercimek-Andrews, Caroline Nava, Manuela Pendziwiat, Richard Person, Gian Paolo Ramelli, Luiza L.P. Ramos, Anita Rauch, Caitlin Reavey, Alessandra Renieri, Angelika Rieß, Amarilis Sanchez-Valle, Shifteh Sattar, Carol Saunders, Niklas Schwarz, Thomas Smol, Myriam Srour, Katharina Steindl, Steffen Syrbe, Jenny C. Taylor, Aida Telegrafi, Isabelle Thiffault, Doris A. Trauner, Helio van der Linden, Silvana van Koningsbruggen, Laurent Villard, Ida Vogel, Julie Vogt, Yvonne G. Weber, Ingrid M. Wentzensen, Elysa Widjaja, Jaroslav Zak, Samantha Baxter, Siddharth Banka, Lance H. Rodan, Jeremy F. McRae, Stephen Clayton, Tomas W. Fitzgerald, Joanna Kaplanis, Elena Prigmore, Diana Rajan, Alejandro Sifrim, Stuart Aitken, Nadia Akawi, Mohsan Alvi, Kirsty Ambridge, Daniel M. Barrett, Tanya Bayzetinova, Philip Jones, Wendy D. Jones, Daniel King, Netravathi Krishnappa, Laura E. Mason, Tarjinder Singh, Adrian R. Tivey, Munaza Ahmed, Uruj Anjum, Hayley Archer, Ruth Armstrong, Jana Awada, Meena Balasubramanian, Diana Baralle, Angela Barnicoat, Paul Batstone, David Baty, Chris Bennett, Jonathan Berg, Birgitta Bernhard, A. Paul Bevan, Maria Bitner-Glindzicz, Edward Blair, Moira Blyth, David Bohanna, Louise Bourdon, David Bourn, Lisa Bradley, Angela Brady, Simon Brent, Carole Brewer, Kate Brunstrom, David J. Bunyan, John Burn, Natalie Canham, Bruce Castle, Kate Chandler, Elena Chatzimichali, Deirdre Cilliers, Angus Clarke, Susan Clasper, Jill Clayton-Smith, Virginia Clowes, Andrea Coates, Trevor Cole, Irina Colgiu, Amanda Collins, Morag N. Collinson, Fiona Connell, Nicola Cooper, Lara Cresswell, Gareth Cross, Yanick Crow, Mariella D’Alessandro, Tabib Dabir, Rosemarie Davidson, Sally Davies, Dylan de Vries, John Dean, Charu Deshpande, Gemma Devlin, Abhijit Dixit, Angus Dobbie, Alan Donaldson, Dian Donnai, Deirdre Donnelly, Carina Donnelly, Angela Douglas, Sofia Douzgou, Alexis Duncan, Jacqueline Eason, Sian Ellard, Ian Ellis, Frances Elmslie, Karenza Evans, Sarah Everest, Tina Fendick, Richard Fisher, Frances Flinter, Nicola Foulds, Andrew Fry, Alan Fryer, Carol Gardiner, Lorraine Gaunt, Neeti Ghali, Richard Gibbons, Harinder Gill, Judith Goodship, David Goudie, Emma Gray, Andrew Green, Philip Greene, Lynn Greenhalgh, Susan Gribble, Rachel Harrison, Lucy Harrison, Victoria Harrison, Rose Hawkins, Liu He, Stephen Hellens, Alex Henderson, Sarah Hewitt, Lucy Hildyard, Emma Hobson, Simon Holden, Muriel Holder, Susan Holder, Georgina Hollingsworth, Tessa Homfray, Mervyn Humphreys, Jane Hurst, Ben Hutton, Stuart Ingram, Melita Irving, Lily Islam, Andrew Jackson, Joanna Jarvis, Lucy Jenkins, Diana Johnson, Elizabeth Jones, Dragana Josifova, Shelagh Joss, Beckie Kaemba, Sandra Kazembe, Rosemary Kelsell, Bronwyn Kerr, Helen Kingston, Usha Kini, Esther Kinning, Gail Kirby, Claire Kirk, Emma Kivuva, Alison Kraus, Dhavendra Kumar, V. K. Ajith Kumar, Katherine Lachlan, Wayne Lam, Anne Lampe, Caroline Langman, Melissa Lees, Derek Lim, Cheryl Longman, Gordon Lowther, Sally A. Lynch, Alex Magee, Eddy Maher, Alison Male, Sahar Mansour, Karen Marks, Katherine Martin, Una Maye, Emma McCann, Vivienne McConnell, Meriel McEntagart, Ruth McGowan, Kirsten McKay, Shane McKee, Dominic J. McMullan, Susan McNerlan, Catherine McWilliam, Sarju Mehta, Kay Metcalfe, Anna Middleton, Zosia Miedzybrodzka, Emma Miles, Shehla Mohammed, Tara Montgomery, David Moore, Sian Morgan, Jenny Morton, Hood Mugalaasi, Victoria Murday, Helen Murphy, Swati Naik, Andrea Nemeth, Louise Nevitt, Ruth Newbury-Ecob, Andrew Norman, Rosie O’Shea, Caroline Ogilvie, Kai-Ren Ong, Soo-Mi Park, Michael J. Parker, Chirag Patel, Joan Paterson, Stewart Payne, Daniel Perrett, Julie Phipps, Daniela T. Pilz, Martin Pollard, Caroline Pottinger, Joanna Poulton, Norman Pratt, Katrina Prescott, Sue Price, Abigail Pridham, Annie Procter, Hellen Purnell, Oliver Quarrell, Nicola Ragge, Raheleh Rahbari, Josh Randall, Julia Rankin, Lucy Raymond, Debbie Rice, Leema Robert, Eileen Roberts, Jonathan Roberts, Paul Roberts, Gillian Roberts, Alison Ross, Elisabeth Rosser, Anand Saggar, Shalaka Samant, Julian Sampson, Richard Sandford, Ajoy Sarkar, Susann Schweiger, Richard Scott, Ingrid Scurr, Ann Selby, Anneke Seller, Cheryl Sequeira, Nora Shannon, Saba Sharif, Charles Shaw-Smith, Emma Shearing, Debbie Shears, Eamonn Sheridan, Ingrid Simonic, Roldan Singzon, Zara Skitt, Audrey Smith, Kath Smith, Sarah Smithson, Linda Sneddon, Miranda Splitt, Miranda Squires, Fiona Stewart, Helen Stewart, Volker Straub, Mohnish Suri, Vivienne Sutton, Ganesh Jawahar Swaminathan, Elizabeth Sweeney, Kate Tatton-Brown, Cat Taylor, Rohan Taylor, Mark Tein, I. Karen Temple, Jenny Thomson, Marc Tischkowitz, Susan Tomkins, Audrey Torokwa, Becky Treacy, Claire Turner, Peter Turnpenny, Carolyn Tysoe, Anthony Vandersteen, Vinod Varghese, Pradeep Vasudevan, Parthiban Vijayarangakannan, Emma Wakeling, Sarah Wallwark, Jonathon Waters, Astrid Weber, Diana Wellesley, Margo Whiteford, Sara Widaa, Sarah Wilcox, Emily Wilkinson, Denise Williams, Nicola Williams, Louise Wilson, Geoff Woods, Christopher Wragg, Michael Wright, Laura Yates, Michael Yau, Chris Nellåker, Michael Parker, Helen V. Firth, Caroline F. Wright, David R. FitzPatrick, Jeffrey C. Barrett, Matthew E. Hurles, Department of Medicine 1, Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Center for Medical Genetics, Istituto di Scienze e Tecnologie della Cognizione, Consiglio Nazionale delle Ricerche (ISTC, CNR), Istituto di Scienze e Tecnologie della Cognizione, Station biologique de Roscoff [Roscoff] (SBR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), CHU Pitié-Salpêtrière [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), Génétique médicale [Centre Hospitalier de Vannes], Centre hospitalier Bretagne Atlantique (Morbihan) (CHBA), Department of Pediatrics, University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, Centre de Génétique Chromosomique [Hôpital Saint Vincent de Paul], Hôpital Saint Vincent de Paul-Groupement des Hôpitaux de l'Institut Catholique de Lille (GHICL), Université catholique de Lille (UCL)-Université catholique de Lille (UCL), Institut de Génétique et Développement de Rennes (IGDR), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)-Structure Fédérative de Recherche en Biologie et Santé de Rennes ( Biosit : Biologie - Santé - Innovation Technologique ), Service de génétique médicale, Centre Hospitalier Universitaire Vaudois [Lausanne] (CHUV), Institute of Human Genetics, Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM)-Helmholtz Zentrum München = German Research Center for Environmental Health, Groupe de Recherche Clinique : Déficience Intellectuelle et Autisme (GRC), Université Pierre et Marie Curie - Paris 6 (UPMC), Children’s Hospital of Philadelphia (CHOP ), Service de Génétique Médicale, Centre hospitalier universitaire de Nantes (CHU Nantes), Department of Public Health Sciences, Karolinska Institutet [Stockholm], Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Baylor University-Baylor University, Institute of Medical Genetics, Universität Zürich [Zürich] = University of Zurich (UZH), Università degli Studi di Camerino = University of Camerino (UNICAM), Centre Hospitalier Régional Universitaire [Lille] (CHRU Lille), University of Oxford, GeneDx [Gaithersburg, MD, USA], Department of Clinical Genetics (Academic Medical Center, University of Amsterdam), VU University Medical Center [Amsterdam], Marseille medical genetics - Centre de génétique médicale de Marseille (MMG), Aix Marseille Université (AMU)-Institut National de la Santé et de la Recherche Médicale (INSERM), Department of Clinical Genetics, Aarhus University Hospital, Boston Children's Hospital, Wellcome Trust Genome Campus, The Wellcome Trust Sanger Institute [Cambridge], Institute of Biomedical Engineering [Oxford] (IBME), Climatic Research Unit, University of East Anglia [Norwich] (UEA), Imperial College London, St Mary's Hospital, East Anglian Medical Genetics Service, Cytogenetics Laboratory, Addenbrooke's Hospital, Sheffield Children's NHS Foundation Trust, Regional Genetic Service, St Mary's Hospital, Manchester, Genetics, University of Southampton, Great Ormond Street Hospital for Children [London] (GOSH), Yorkshire Regional Clinical Genetics Service, Chapel Allerton Hospital, Molecular and Clinical Medicine [Dundee, UK] (School of Medicine), University of Dundee [UK]-Ninewells Hospital & Medical School [Dundee, UK], Department of Clinical Genetics, Oxford Regional Genetics Service, The Churchill hospital, North West Thames Regional Genetics, Northwick Park Hospital, Royal Devon & Exeter Hospital, Wessex Clinical Genetics Service, Wessex clinical genetics service, Manchester University NHS Foundation Trust (MFT), West Midlands Regional Genetics Service, Birmingham Women's and Children's NHS Foundation Trust, Our Lady's hospital for Sick Children, Our Lady's Hospital for Sick Children, Guy's Hospital [London], University Hospitals Leicester, University of Edinburgh, Belfast City Hospital, Ferguson-Smith Centre for Clinical Genetics, Yorkhill Hospitals, Institute of Medical Genetics, Heath Park, Cardiff, The London Clinic, Nottingham City Hospital, Clinical Genetics Department, St Michael's Hospital, Department of Genetic Medicine, Nottingham Clinical Genetics Service, Nottingham University Hospitals NHS Trust (NUH), Royal Devon and Exeter Foundation Trust, Histopathology, St. George's Hospital, Teesside Genetics Unit, James Cook University (JCU), Kansas State University, Liverpool Women's NHS Foundation Trust, Department of Medical Genetics, HMNC Brain Health, North West Thames Regional Genetics Service, Northwick Park Hospital, Harrow, Leicester Royal Infirmary, University Hospitals Leicester-University Hospitals Leicester, Ninewells Hospital and Medical School [Dundee], Academic Centre on Rare Diseases (ACoRD), University College Dublin [Dublin] (UCD), Oxford Brookes University, Institute of medicinal plant development, Chinese Academy of Medical Sciences, Newcastle Upon Tyne Hospitals NHS Trust, Service d'explorations fonctionnelles respiratoires [Lille], Department of Computer Science - Trinity College Dublin, University of Dublin, Department of Clinical Genetics (Sheffield Children’s NHS Foundation Trust), Division of Medical & Molecular Genetics, NHS Greater Glasgow & Clyde [Glasgow] (NHSGGC), Department of Clinical Genetics [Churchill Hospital], Churchill Hospital Oxford Centre for Haematology, Weizmann Institute of Science [Rehovot, Israël], Southampton General Hospital, Western General Hospital, Head of the Department of Medical Genetics, University of Birmingham [Birmingham], SW Thames Regional Genetics Service, St Georgeâ™s University of London, London, Institut Cochin (IC UM3 (UMR 8104 / U1016)), Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), All Wales Medical Genetics Services, Singleton Hospital, Central Manchester University Hospitals NHS Foundation Trust, University of North Texas (UNT), Clinical Genetics, Northern Genetics Service, Newcastle University [Newcastle], United Kingdom Met Office [Exeter], Institute of Medical Genetics (University Hospital of Wales), University Hospital of Wales (UHW), West Midlands Regional Genetics Laboratory and Clinical Genetics Unit, Birmingham Women's Hospital, Laboratory of Molecular Genetics, National Institute of Child Health and Human Development, National Institutes of Health, Department of Genetics, Cell- and Immunobiology, Semmelweis University, University Hospitals Bristol, Marketing (MKT), EESC-GEM Grenoble Ecole de Management, Addenbrookes Hospital, West of Scotland Genetics Service (Queen Elizabeth University Hospital), University Hospital Birmingham Queen Elizabeth, Department of Clnical Genetics, Chapel Allerton Hospital, Department of Clinical Genetics, Northampton General Hospital, Northampton, Royal Devon and Exeter Hospital [Exeter, UK] (RDEH), Guy's and St Thomas' Hospital [London], School of Computer Science, Bangor University, University Hospital Southampton, Clinical Genetics Unit, St Georges, University of London, Medical Genetics, Cardiff University, Research and Development, Futurelab, Nottingham Regional Genetics Service [Nottingham, UK], Nottingham University Hospitals NHS Trust (NUH)-City Hospital Campus [Nottingham, UK], University of St Andrews [Scotland], Clinical Genetics Service, Nottingham University Hospitals NHS Trust - City Hospital Campus, West Midlands Regional Genetics Unit, Department of Neurology, Johns Hopkins University (JHU), Oxford University Hospitals NHS Trust, St James's University Hospital, Leeds Teaching Hospitals NHS Trust, Addenbrooke's Hospital, Cambridge University NHS Trust, Institute of Human Genetics, Newcastle, Division of Biological Stress Response [Amsterdam, The Netherlands], The Netherlands Cancer Institute [Amsterdam, The Netherlands], Johns Hopkins Bloomberg School of Public Health [Baltimore], Birmingham Women’s Hospital, Department of Genetics, Portuguese Oncology Institute, Molecular Genetics, IWK Health Centre, IWK health centre, North West london hospitals NHS Trust, Department of Clinical Genetics (Queen Elizabeth University Hospital, Glasgow), Queen Elizabeth University Hospital (Glasgow), Birmingham women's hospital, Birmingham, Ethox Centre, Department of Public Health and Primary Health Care, University of Oxford, Badenoch Building, Old Road Campus, Headington, R01 HD091846, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Human Genome Research Institute, National Institutes of Health’s National Institute of Child Health and Human Development, Boston Children’s Hospital Faculty Development Fellowship, UM1HG008900, Broad Center for Mendelian Genomics, Chile’s National Commission for Scientific and Technological Research, DFG WE4896/3-1, German Research Society, WT 100127, Health Innovation Challenge Fund, Comprehensive Clinical Research Network, Skaggs-Oxford Scholarship, 10/H0305/83, Cambridge South REC, REC GEN/284/12, Republic of Ireland, WT098051, Wellcome Sanger Institute, 72160007, Comisión Nacional de Investigación Científica y Tecnológica, Children's Hospital of Philadelphia, Technische Universität Kaiserslautern, 1DH1813319, Dietmar Hopp Stiftung, National Institute for Health Research, Department of Health & Social Care, Service de neurologie 1 [CHU Pitié-Salpétrière], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-CHU Pitié-Salpêtrière [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Sorbonne Université (SU), Hôpital Saint Vincent de Paul-GHICL, Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)-Structure Fédérative de Recherche en Biologie et Santé de Rennes ( Biosit : Biologie - Santé - Innovation Technologique ), Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM)-Helmholtz-Zentrum München (HZM)-German Research Center for Environmental Health, Service de Génétique Cytogénétique et Embryologie [CHU Pitié-Salpêtrière], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), Università degli Studi di Camerino (UNICAM), University of Oxford [Oxford], Institut National de la Santé et de la Recherche Médicale (INSERM)-Aix Marseille Université (AMU), Nottingham University Hospitals NHS Trust, Nottingham University Hospitals, SW Thames Regional Genetics Service, St George’s University of London, London, University Hospital of Wales, Grenoble Ecole de Management, Royal Devon and Exeter Hospital, City Hospital Campus [Nottingham, UK]-Nottingham University Hospitals NHS Trust [UK], ANS - Complex Trait Genetics, Human Genetics, ARD - Amsterdam Reproduction and Development, ACS - Pulmonary hypertension & thrombosis, Service de Neurologie [CHU Pitié-Salpêtrière], IFR70-CHU Pitié-Salpêtrière [AP-HP], GHICL-Hôpital Saint Vincent de Paul, Centre National de la Recherche Scientifique (CNRS)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), Université Friedrich-Alexander d'Erlangen-Nuremberg, Assistance publique - Hôpitaux de Paris (AP-HP) (APHP)-CHU Pitié-Salpêtrière [APHP], Centre Hospitalier Bretagne Atlantique [Vannes], Technische Universität München [München] (TUM)-Helmholtz-Zentrum München (HZM)-German Research Center for Environmental Health, Service de Génétique et Cytogénétique [CHU Pitié-Salpêtrière], University of Zürich [Zürich] (UZH), Università di Camerino (UNICAM), Birmingham Women's Hospital Healthcare NHS Trust, University Hospitals of Leicester, Sheffield Children’s Hospital, Weizmann Institute of Science, and Grenoble Ecole de Management (GEM)

Subjects
0301 basic medicine, Male, Microcephaly, [SDV]Life Sciences [q-bio], Haploinsufficiency, autism, epilepsy, epileptic encephalopathy, global developmental delay, H3K4 methylation, intellectual disability, KMT2E, neurodevelopmental disorder, Adolescent, Adult, Child, Child, Preschool, DNA-Binding Proteins, Epilepsy, Female, Humans, Infant, Neurodevelopmental Disorders, Pedigree, Phenotype, Young Adult, Genetic Variation, Heterozygote, 0302 clinical medicine, Neurodevelopmental disorder, Intellectual disability, Global developmental delay, Genetics (clinical), ComputingMilieux_MISCELLANEOUS, Genetics, 0303 health sciences, Hypotonia, 030220 oncology & carcinogenesis, medicine.symptom, Rare cancers Radboud Institute for Health Sciences [Radboudumc 9], 03 medical and health sciences, Report, medicine, Journal Article, Expressivity (genetics), Preschool, 030304 developmental biology, [SDV.GEN]Life Sciences [q-bio]/Genetics, business.industry, Macrocephaly, medicine.disease, 030104 developmental biology, [SDV.GEN.GH]Life Sciences [q-bio]/Genetics/Human genetics, Autism, business, 030217 neurology & neurosurgery
Abstract

Contains fulltext : 206572.pdf (Publisher’s version ) (Open Access) We delineate a KMT2E-related neurodevelopmental disorder on the basis of 38 individuals in 36 families. This study includes 31 distinct heterozygous variants in KMT2E (28 ascertained from Matchmaker Exchange and three previously reported), and four individuals with chromosome 7q22.2-22.23 microdeletions encompassing KMT2E (one previously reported). Almost all variants occurred de novo, and most were truncating. Most affected individuals with protein-truncating variants presented with mild intellectual disability. One-quarter of individuals met criteria for autism. Additional common features include macrocephaly, hypotonia, functional gastrointestinal abnormalities, and a subtle facial gestalt. Epilepsy was present in about one-fifth of individuals with truncating variants and was responsive to treatment with anti-epileptic medications in almost all. More than 70% of the individuals were male, and expressivity was variable by sex; epilepsy was more common in females and autism more common in males. The four individuals with microdeletions encompassing KMT2E generally presented similarly to those with truncating variants, but the degree of developmental delay was greater. The group of four individuals with missense variants in KMT2E presented with the most severe developmental delays. Epilepsy was present in all individuals with missense variants, often manifesting as treatment-resistant infantile epileptic encephalopathy. Microcephaly was also common in this group. Haploinsufficiency versus gain-of-function or dominant-negative effects specific to these missense variants in KMT2E might explain this divergence in phenotype, but requires independent validation. Disruptive variants in KMT2E are an under-recognized cause of neurodevelopmental abnormalities.

Published
2019
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8. Bi-allelic Loss-of-Function CACNA1B Mutations in Progressive Epilepsy-Dyskinesia

Author

Kathleen M. Gorman, Esther Meyer, Detelina Grozeva, Egidio Spinelli, Amy McTague, Alba Sanchis-Juan, Keren J. Carss, Emily Bryant, Adi Reich, Amy L. Schneider, Ronit M. Pressler, Michael A. Simpson, Geoff D. Debelle, Evangeline Wassmer, Jenny Morton, Diana Sieciechowicz, Eric Jan-Kamsteeg, Alex R. Paciorkowski, Mary D. King, J. Helen Cross, Annapurna Poduri, Heather C. Mefford, Ingrid E. Scheffer, Tobias B. Haack, Gary McCullagh, John J. Millichap, Gemma L. Carvill, Jill Clayton-Smith, Eamonn R. Maher, F. Lucy Raymond, Manju A. Kurian, Jeremy F. McRae, Stephen Clayton, Tomas W. Fitzgerald, Joanna Kaplanis, Elena Prigmore, Diana Rajan, Alejandro Sifrim, Stuart Aitken, Nadia Akawi, Mohsan Alvi, Kirsty Ambridge, Daniel M. Barrett, Tanya Bayzetinova, Philip Jones, Wendy D. Jones, Daniel King, Netravathi Krishnappa, Laura E. Mason, Tarjinder Singh, Adrian R. Tivey, Munaza Ahmed, Uruj Anjum, Hayley Archer, Ruth Armstrong, Jana Awada, Meena Balasubramanian, Siddharth Banka, Diana Baralle, Angela Barnicoat, Paul Batstone, David Baty, Chris Bennett, Jonathan Berg, Birgitta Bernhard, A. Paul Bevan, Maria Bitner-Glindzicz, Edward Blair, Moira Blyth, David Bohanna, Louise Bourdon, David Bourn, Lisa Bradley, Angela Brady, Simon Brent, Carole Brewer, Kate Brunstrom, David J. Bunyan, John Burn, Natalie Canham, Bruce Castle, Kate Chandler, Elena Chatzimichali, Deirdre Cilliers, Angus Clarke, Susan Clasper, Virginia Clowes, Andrea Coates, Trevor Cole, Irina Colgiu, Amanda Collins, Morag N. Collinson, Fiona Connell, Nicola Cooper, Helen Cox, Lara Cresswell, Gareth Cross, Yanick Crow, Mariella D’Alessandro, Tabib Dabir, Rosemarie Davidson, Sally Davies, Dylan de Vries, John Dean, Charu Deshpande, Gemma Devlin, Abhijit Dixit, Angus Dobbie, Alan Donaldson, Dian Donnai, Deirdre Donnelly, Carina Donnelly, Angela Douglas, Sofia Douzgou, Alexis Duncan, Jacqueline Eason, Sian Ellard, Ian Ellis, Frances Elmslie, Karenza Evans, Sarah Everest, Tina Fendick, Richard Fisher, Frances Flinter, Nicola Foulds, Andrew Fry, Alan Fryer, Carol Gardiner, Lorraine Gaunt, Neeti Ghali, Richard Gibbons, Harinder Gill, Judith Goodship, David Goudie, Emma Gray, Andrew Green, Philip Greene, Lynn Greenhalgh, Susan Gribble, Rachel Harrison, Lucy Harrison, Victoria Harrison, Rose Hawkins, Liu He, Stephen Hellens, Alex Henderson, Sarah Hewitt, Lucy Hildyard, Emma Hobson, Simon Holden, Muriel Holder, Susan Holder, Georgina Hollingsworth, Tessa Homfray, Mervyn Humphreys, Jane Hurst, Ben Hutton, Stuart Ingram, Melita Irving, Lily Islam, Andrew Jackson, Joanna Jarvis, Lucy Jenkins, Diana Johnson, Elizabeth Jones, Dragana Josifova, Shelagh Joss, Beckie Kaemba, Sandra Kazembe, Rosemary Kelsell, Bronwyn Kerr, Helen Kingston, Usha Kini, Esther Kinning, Gail Kirby, Claire Kirk, Emma Kivuva, Alison Kraus, Dhavendra Kumar, V. K. Ajith Kumar, Katherine Lachlan, Wayne Lam, Anne Lampe, Caroline Langman, Melissa Lees, Derek Lim, Cheryl Longman, Gordon Lowther, Sally A. Lynch, Alex Magee, Eddy Maher, Alison Male, Sahar Mansour, Karen Marks, Katherine Martin, Una Maye, Emma McCann, Vivienne McConnell, Meriel McEntagart, Ruth McGowan, Kirsten McKay, Shane McKee, Dominic J. McMullan, Susan McNerlan, Catherine McWilliam, Sarju Mehta, Kay Metcalfe, Anna Middleton, Zosia Miedzybrodzka, Emma Miles, Shehla Mohammed, Tara Montgomery, David Moore, Sian Morgan, Hood Mugalaasi, Victoria Murday, Helen Murphy, Swati Naik, Andrea Nemeth, Louise Nevitt, Ruth Newbury-Ecob, Andrew Norman, Rosie O’Shea, Caroline Ogilvie, Kai-Ren Ong, Soo-Mi Park, Michael J. Parker, Chirag Patel, Joan Paterson, Stewart Payne, Daniel Perrett, Julie Phipps, Daniela T. Pilz, Martin Pollard, Caroline Pottinger, Joanna Poulton, Norman Pratt, Katrina Prescott, Sue Price, Abigail Pridham, Annie Procter, Hellen Purnell, Oliver Quarrell, Nicola Ragge, Raheleh Rahbari, Josh Randall, Julia Rankin, Lucy Raymond, Debbie Rice, Leema Robert, Eileen Roberts, Jonathan Roberts, Paul Roberts, Gillian Roberts, Alison Ross, Elisabeth Rosser, Anand Saggar, Shalaka Samant, Julian Sampson, Richard Sandford, Ajoy Sarkar, Susann Schweiger, Richard Scott, Ingrid Scurr, Ann Selby, Anneke Seller, Cheryl Sequeira, Nora Shannon, Saba Sharif, Charles Shaw-Smith, Emma Shearing, Debbie Shears, Eamonn Sheridan, Ingrid Simonic, Roldan Singzon, Zara Skitt, Audrey Smith, Kath Smith, Sarah Smithson, Linda Sneddon, Miranda Splitt, Miranda Squires, Fiona Stewart, Helen Stewart, Volker Straub, Mohnish Suri, Vivienne Sutton, Ganesh Jawahar Swaminathan, Elizabeth Sweeney, Kate Tatton-Brown, Cat Taylor, Rohan Taylor, Mark Tein, I. Karen Temple, Jenny Thomson, Marc Tischkowitz, Susan Tomkins, Audrey Torokwa, Becky Treacy, Claire Turner, Peter Turnpenny, Carolyn Tysoe, Anthony Vandersteen, Vinod Varghese, Pradeep Vasudevan, Parthiban Vijayarangakannan, Julie Vogt, Emma Wakeling, Sarah Wallwark, Jonathon Waters, Astrid Weber, Diana Wellesley, Margo Whiteford, Sara Widaa, Sarah Wilcox, Emily Wilkinson, Denise Williams, Nicola Williams, Louise Wilson, Geoff Woods, Christopher Wragg, Michael Wright, Laura Yates, Michael Yau, Chris Nellåker, Michael Parker, Helen V. Firth, Caroline F. Wright, David R. FitzPatrick, Jeffrey C. Barrett, Matthew E. Hurles, Saeed Al Turki, Carl Anderson, Richard Anney, Dinu Antony, Maria Soler Artigas, Muhammad Ayub, Senduran Balasubramaniam, Inês Barroso, Phil Beales, Jamie Bentham, Shoumo Bhattacharya, Ewan Birney, Douglas Blackwood, Martin Bobrow, Elena Bochukova, Patrick Bolton, Rebecca Bounds, Chris Boustred, Gerome Breen, Mattia Calissano, Keren Carss, Krishna Chatterjee, Lu Chen, Antonio Ciampi, Sebhattin Cirak, Peter Clapham, Gail Clement, Guy Coates, David Collier, Catherine Cosgrove, Tony Cox, Nick Craddock, Lucy Crooks, Sarah Curran, David Curtis, Allan Daly, Aaron Day-Williams, Ian N.M. Day, Thomas Down, Yuanping Du, Ian Dunham, Sarah Edkins, Peter Ellis, David Evans, Sadaf Faroogi, Ghazaleh Fatemifar, David R. Fitzpatrick, Paul Flicek, James Flyod, A. Reghan Foley, Christopher S. Franklin, Marta Futema, Louise Gallagher, Matthias Geihs, Daniel Geschwind, Heather Griffin, Xueqin Guo, Xiaosen Guo, Hugh Gurling, Deborah Hart, Audrey Hendricks, Peter Holmans, Bryan Howie, Liren Huang, Tim Hubbard, Steve E. Humphries, Pirro Hysi, David K. Jackson, Yalda Jamshidi, Tian Jing, Chris Joyce, Jane Kaye, Thomas Keane, Julia Keogh, John Kemp, Karen Kennedy, Anja Kolb-Kokocinski, Genevieve Lachance, Cordelia Langford, Daniel Lawson, Irene Lee, Monkol Lek, Jieqin Liang, Hong Lin, Rui Li, Yingrui Li, Ryan Liu, Jouko Lönnqvist, Margarida Lopes, Valentina Iotchkova, Daniel MacArthur, Jonathan Marchini, John Maslen, Mangino Massimo, Iain Mathieson, Gaëlle Marenne, Peter McGuffin, Andrew McIntosh, Andrew G. McKechanie, Andrew McQuillin, Sarah Metrustry, Hannah Mitchison, Alireza Moayyeri, James Morris, Francesco Muntoni, Kate Northstone, Michael O'Donnovan, Alexandros Onoufriadis, Stephen O'Rahilly, Karim Oualkacha, Michael J. Owen, Aarno Palotie, Kalliope Panoutsopoulou, Victoria Parker, Jeremy R. Parr, Lavinia Paternoster, Tiina Paunio, Felicity Payne, Olli Pietilainen, Vincent Plagnol, Lydia Quaye, Michael A. Quail, Karola Rehnström, Susan Ring, Graham R.S. Ritchie, Nicola Roberts, David B. Savage, Peter Scambler, Stephen Schiffels, Miriam Schmidts, Nadia Schoenmakers, Robert K. Semple, Eva Serra, Sally I. Sharp, So-Youn Shin, David Skuse, Kerrin Small, Lorraine Southam, Olivera Spasic-Boskovic, David St Clair, Jim Stalker, Elizabeth Stevens, Beate St Pourcian, Jianping Sun, Jaana Suvisaari, Ionna Tachmazidou, Martin D. Tobin, Ana Valdes, Margriet Van Kogelenberg, Peter M. Visscher, Louise V. Wain, James T.R. Walters, Guangbiao Wang, Jun Wang, Yu Wang, Kirsten Ward, Elanor Wheeler, Tamieka Whyte, Hywel Williams, Kathleen A. Williamson, Crispian Wilson, Kim Wong, ChangJiang Xu, Jian Yang, Fend Zhang, Pingbo Zhang, Timothy Aitman, Hana Alachkar, Sonia Ali, Louise Allen, David Allsup, Gautum Ambegaonkar, Julie Anderson, Richard Antrobus, Gavin Arno, Gururaj Arumugakani, Sofie Ashford, William Astle, Antony Attwood, Steve Austin, Chiara Bacchelli, Tamam Bakchoul, Tadbir K. Bariana, Helen Baxendale, David Bennett, Claire Bethune, Shahnaz Bibi, Marta Bleda, Harm Boggard, Paula Bolton-Maggs, Claire Booth, John R. Bradley, Angie Brady, Matthew Brown, Michael Browning, Christine Bryson, Siobhan Burns, Paul Calleja, Jenny Carmichael, Mark Caulfield, Elizabeth Chalmers, Anita Chandra, Patrick Chinnery, Manali Chitre, Colin Church, Emma Clement, Naomi Clements-Brod, Gerry Coghlan, Peter Collins, Nichola Cooper, Amanda Creaser-Myers, Rosa DaCosta, Louise Daugherty, Sophie Davies, John Davis, Minka De Vries, Patrick Deegan, Sri V.V. Deevi, Lisa Devlin, Eleanor Dewhurst, Rainer Doffinger, Natalie Dormand, Elizabeth Drewe, David Edgar, William Egner, Wendy N. Erber, Marie Erwood, Tamara Everington, Remi Favier, Helen Firth, Debra Fletcher, James C. Fox, Amy Frary, Kathleen Freson, Bruce Furie, Abigail Furnell, Daniel Gale, Alice Gardham, Michael Gattens, Pavandeep K. Ghataorhe, Rohit Ghurye, Simon Gibbs, Kimberley Gilmour, Paul Gissen, Sarah Goddard, Keith Gomez, Pavel Gordins, Stefan Gräf, Daniel Greene, Alan Greenhalgh, Andreas Greinacher, Sofia Grigoriadou, Scott Hackett, Charaka Hadinnapola, Rosie Hague, Matthias Haimel, Csaba Halmagyi, Tracey Hammerton, Daniel Hart, Grant Hayman, Johan W.M. Heemskerk, Robert Henderson, Anke Hensiek, Yvonne Henskens, Archana Herwadkar, Fengyuan Hu, Aarnoud Huissoon, Marc Humbert, Roger James, Stephen Jolles, Rashid Kazmi, David Keeling, Peter Kelleher, Anne M. Kelly, Fiona Kennedy, David Kiely, Nathalie Kingston, Ania Koziell, Deepa Krishnakumar, Taco W. Kuijpers, Dinakantha Kumararatne, Manju Kurian, Michael A. Laffan, Michele P. Lambert, Hana Lango Allen, Allan Lawrie, Sara Lear, Claire Lentaigne, Ri Liesner, Rachel Linger, Hilary Longhurst, Lorena Lorenzo, Rajiv Machado, Rob Mackenzie, Robert MacLaren, Eamonn Maher, Jesmeen Maimaris, Sarah Mangles, Ania Manson, Rutendo Mapeta, Hugh S. Markus, Jennifer Martin, Larahmie Masati, Mary Mathias, Vera Matser, Anna Maw, Elizabeth McDermott, Coleen McJannet, Stuart Meacham, Sharon Meehan, Karyn Megy, Michel Michaelides, Carolyn M. Millar, Shahin Moledina, Anthony Moore, Nicholas Morrell, Andrew Mumford, Sai Murng, Elaine Murphy, Sergey Nejentsev, Sadia Noorani, Paquita Nurden, Eric Oksenhendler, Willem H. Ouwehand, Sofia Papadia, Alasdair Parker, John Pasi, Chris Patch, Jeanette Payne, Andrew Peacock, Kathelijne Peerlinck, Christopher J. Penkett, Joanna Pepke-Zaba, David J. Perry, Val Pollock, Gary Polwarth, Mark Ponsford, Waseem Qasim, Isabella Quinti, Stuart Rankin, Karola Rehnstrom, Evan Reid, Christopher J. Rhodes, Michael Richards, Sylvia Richardson, Alex Richter, Irene Roberts, Matthew Rondina, Catherine Roughley, Kevin Rue-Albrecht, Crina Samarghitean, Saikat Santra, Ravishankar Sargur, Sinisa Savic, Sol Schulman, Harald Schulze, Marie Scully, Suranjith Seneviratne, Carrock Sewell, Olga Shamardina, Debbie Shipley, Ilenia Simeoni, Suthesh Sivapalaratnam, Kenneth Smith, Aman Sohal, Laura Southgate, Simon Staines, Emily Staples, Hans Stauss, Penelope Stein, Jonathan Stephens, Kathleen Stirrups, Sophie Stock, Jay Suntharalingam, R. Campbell Tait, Kate Talks, Yvonne Tan, Jecko Thachil, James Thaventhiran, Ellen Thomas, Moira Thomas, Dorothy Thompson, Adrian Thrasher, Catherine Titterton, Cheng-Hock Toh, Mark Toshner, Carmen Treacy, Richard Trembath, Salih Tuna, Wojciech Turek, Ernest Turro, Chris Van Geet, Marijke Veltman, Julie von Ziegenweldt, Anton Vonk Noordegraaf, Ivy Wanjiku, Timothy Q. Warner, Hugh Watkins, Andrew Webster, Steve Welch, Sarah Westbury, John Wharton, Deborah Whitehorn, Martin Wilkins, Lisa Willcocks, Catherine Williamson, Geoffrey Woods, John Wort, Nigel Yeatman, Patrick Yong, Tim Young, Ping Yu, Paediatric Infectious Diseases / Rheumatology / Immunology, ARD - Amsterdam Reproduction and Development, Pediatric surgery, APH - Aging & Later Life, Molecular cell biology and Immunology, Pulmonary medicine, ACS - Pulmonary hypertension & thrombosis, and APH - Quality of Care

Subjects
0301 basic medicine, Male, Adolescent, Loss of Heterozygosity, Context (language use), Postnatal microcephaly, Neurotransmission, medicine.disease_cause, Bioinformatics, Synaptic Transmission, Loss of heterozygosity, 03 medical and health sciences, Epilepsy, 0302 clinical medicine, Calcium Channels, N-Type, Report, Genetics, medicine, Humans, Child, Genetics (clinical), Mutation, Dyskinesias, business.industry, Infant, medicine.disease, Hypotonia, Pedigree, 030104 developmental biology, Dyskinesia, Child, Preschool, Calcium, Female, medicine.symptom, business, 030217 neurology & neurosurgery
Abstract

© 2019 American Society of Human Genetics The occurrence of non-epileptic hyperkinetic movements in the context of developmental epileptic encephalopathies is an increasingly recognized phenomenon. Identification of causative mutations provides an important insight into common pathogenic mechanisms that cause both seizures and abnormal motor control. We report bi-allelic loss-of-function CACNA1B variants in six children from three unrelated families whose affected members present with a complex and progressive neurological syndrome. All affected individuals presented with epileptic encephalopathy, severe neurodevelopmental delay (often with regression), and a hyperkinetic movement disorder. Additional neurological features included postnatal microcephaly and hypotonia. Five children died in childhood or adolescence (mean age of death: 9 years), mainly as a result of secondary respiratory complications. CACNA1B encodes the pore-forming subunit of the pre-synaptic neuronal voltage-gated calcium channel Cav2.2/N-type, crucial for SNARE-mediated neurotransmission, particularly in the early postnatal period. Bi-allelic loss-of-function variants in CACNA1B are predicted to cause disruption of Ca2+ influx, leading to impaired synaptic neurotransmission. The resultant effect on neuronal function is likely to be important in the development of involuntary movements and epilepsy. Overall, our findings provide further evidence for the key role of Cav2.2 in normal human neurodevelopment.

Published
2018
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9. A New, Atypical Case of Cobalamin F Disorder Diagnosed by Whole Exome Sequencing

Author

Shalaka Samant, Panayiotis Constantinou, John Dean, Paul Lochhead, Mariella D'Alessandro, W. Michael Bisset, and Catherine Hauptfleisch

Subjects
Pediatrics, medicine.medical_specialty, Unilateral renal agenesis, Pathology, business.industry, Prominent metopic suture, Compound heterozygosity, Cobalamin, LMBRD1 mutation, 3. Good health, chemistry.chemical_compound, chemistry, Novel Insights from Clinical Practice, Failure to thrive, Cobalamin F disorder, Genetics, medicine, medicine.symptom, LMBRD1 gene, business, Genetics (clinical), Exome sequencing
Abstract

Cobalamin F (cblF) disorder, caused by homozygous or compound heterozygous mutations in the LMBRD1 gene, is a recognised cause of developmental delay, pancytopaenia and failure to thrive which may present in the neonatal period. A handful of cases have been reported in the medical literature. We report a new case, diagnosed at the age of 6 years through whole exome sequencing, with atypical features including prominent metopic suture, cleft palate, unilateral renal agenesis and liver abnormalities, which broaden the phenotypic spectrum.

Published
2015

10. MOESM1 of A strategy to identify a ketoreductase that preferentially synthesizes pharmaceutically relevant (S)-alcohols using whole-cell biotransformation

Author

Saiful Haq, Anirudh Shanbhag, Subbulakshmi Karthikeyan, Hassan, Imran, Kannan Thanukrishnan, Abhishek Ashok, Sunilkumar Sukumaran, S. Ramaswamy, Nagakumar Bharatham, Santanu Datta, Shalaka Samant, and Nainesh Katagihallimath

Subjects
InformationSystems_INFORMATIONSTORAGEANDRETRIEVAL, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, ComputingMilieux_COMPUTERSANDEDUCATION, Data_FILES, ComputerApplications_COMPUTERSINOTHERSYSTEMS
Abstract

Additional file 1. Supplementary Information.

Published
2018
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11. Histone Lysine Methylases and Demethylases in the Landscape of Human Developmental Disorders

Author

Víctor Faundes, William G. Newman, Laura Bernardini, Natalie Canham, Jill Clayton-Smith, Bruno Dallapiccola, Sally J. Davies, Michelle K. Demos, Amy Goldman, Harinder Gill, Rachel Horton, Bronwyn Kerr, Dhavendra Kumar, Anna Lehman, Shane McKee, Jenny Morton, Michael J. Parker, Julia Rankin, Lisa Robertson, I. Karen Temple, Siddharth Banka, Shelin Adam, Christèle du Souich, Alison M. Elliott, Jill Mwenifumbo, Tanya N. Nelson, Clara van Karnebeek, Jan M. Friedman, Jeremy F. McRae, Stephen Clayton, Tomas W. Fitzgerald, Joanna Kaplanis, Elena Prigmore, Diana Rajan, Alejandro Sifrim, Stuart Aitken, Nadia Akawi, Mohsan Alvi, Kirsty Ambridge, Daniel M. Barrett, Tanya Bayzetinova, Philip Jones, Wendy D. Jones, Daniel King, Netravathi Krishnappa, Laura E. Mason, Tarjinder Singh, Adrian R. Tivey, Munaza Ahmed, Uruj Anjum, Hayley Archer, Ruth Armstrong, Jana Awada, Meena Balasubramanian, Diana Baralle, Angela Barnicoat, Paul Batstone, David Baty, Chris Bennett, Jonathan Berg, Birgitta Bernhard, A. Paul Bevan, Maria Bitner-Glindzicz, Edward Blair, Moira Blyth, David Bohanna, Louise Bourdon, David Bourn, Lisa Bradley, Angela Brady, Simon Brent, Carole Brewer, Kate Brunstrom, David J. Bunyan, John Burn, Bruce Castle, Kate Chandler, Elena Chatzimichali, Deirdre Cilliers, Angus Clarke, Susan Clasper, Virginia Clowes, Andrea Coates, Trevor Cole, Irina Colgiu, Amanda Collins, Morag N. Collinson, Fiona Connell, Nicola Cooper, Helen Cox, Lara Cresswell, Gareth Cross, Yanick Crow, Mariella D’Alessandro, Tabib Dabir, Rosemarie Davidson, Sally Davies, Dylan de Vries, John Dean, Charu Deshpande, Gemma Devlin, Abhijit Dixit, Angus Dobbie, Alan Donaldson, Dian Donnai, Deirdre Donnelly, Carina Donnelly, Angela Douglas, Sofia Douzgou, Alexis Duncan, Jacqueline Eason, Sian Ellard, Ian Ellis, Frances Elmslie, Karenza Evans, Sarah Everest, Tina Fendick, Richard Fisher, Frances Flinter, Nicola Foulds, Andrew Fry, Alan Fryer, Carol Gardiner, Lorraine Gaunt, Neeti Ghali, Richard Gibbons, Judith Goodship, David Goudie, Emma Gray, Andrew Green, Philip Greene, Lynn Greenhalgh, Susan Gribble, Rachel Harrison, Lucy Harrison, Victoria Harrison, Rose Hawkins, Liu He, Stephen Hellens, Alex Henderson, Sarah Hewitt, Lucy Hildyard, Emma Hobson, Simon Holden, Muriel Holder, Susan Holder, Georgina Hollingsworth, Tessa Homfray, Mervyn Humphreys, Jane Hurst, Ben Hutton, Stuart Ingram, Melita Irving, Lily Islam, Andrew Jackson, Joanna Jarvis, Lucy Jenkins, Diana Johnson, Elizabeth Jones, Dragana Josifova, Shelagh Joss, Beckie Kaemba, Sandra Kazembe, Rosemary Kelsell, Helen Kingston, Usha Kini, Esther Kinning, Gail Kirby, Claire Kirk, Emma Kivuva, Alison Kraus, V.K. Ajith Kumar, Katherine Lachlan, Wayne Lam, Anne Lampe, Caroline Langman, Melissa Lees, Derek Lim, Cheryl Longman, Gordon Lowther, Sally A. Lynch, Alex Magee, Eddy Maher, Alison Male, Sahar Mansour, Karen Marks, Katherine Martin, Una Maye, Emma McCann, Vivienne McConnell, Meriel McEntagart, Ruth McGowan, Kirsten McKay, Dominic J. McMullan, Susan McNerlan, Catherine McWilliam, Sarju Mehta, Kay Metcalfe, Anna Middleton, Zosia Miedzybrodzka, Emma Miles, Shehla Mohammed, Tara Montgomery, David Moore, Sian Morgan, Hood Mugalaasi, Victoria Murday, Helen Murphy, Swati Naik, Andrea Nemeth, Louise Nevitt, Ruth Newbury-Ecob, Andrew Norman, Rosie O’Shea, Caroline Ogilvie, Kai-Ren Ong, Soo-Mi Park, Chirag Patel, Joan Paterson, Stewart Payne, Daniel Perrett, Julie Phipps, Daniela T. Pilz, Martin Pollard, Caroline Pottinger, Joanna Poulton, Norman Pratt, Katrina Prescott, Sue Price, Abigail Pridham, Annie Procter, Hellen Purnell, Oliver Quarrell, Nicola Ragge, Raheleh Rahbari, Josh Randall, Lucy Raymond, Debbie Rice, Leema Robert, Eileen Roberts, Jonathan Roberts, Paul Roberts, Gillian Roberts, Alison Ross, Elisabeth Rosser, Anand Saggar, Shalaka Samant, Julian Sampson, Richard Sandford, Ajoy Sarkar, Susann Schweiger, Richard Scott, Ingrid Scurr, Ann Selby, Anneke Seller, Cheryl Sequeira, Nora Shannon, Saba Sharif, Charles Shaw-Smith, Emma Shearing, Debbie Shears, Eamonn Sheridan, Ingrid Simonic, Roldan Singzon, Zara Skitt, Audrey Smith, Kath Smith, Sarah Smithson, Linda Sneddon, Miranda Splitt, Miranda Squires, Fiona Stewart, Helen Stewart, Volker Straub, Mohnish Suri, Vivienne Sutton, Ganesh Jawahar Swaminathan, Elizabeth Sweeney, Kate Tatton-Brown, Cat Taylor, Rohan Taylor, Mark Tein, Jenny Thomson, Marc Tischkowitz, Susan Tomkins, Audrey Torokwa, Becky Treacy, Claire Turner, Peter Turnpenny, Carolyn Tysoe, Anthony Vandersteen, Vinod Varghese, Pradeep Vasudevan, Parthiban Vijayarangakannan, Julie Vogt, Emma Wakeling, Sarah Wallwark, Jonathon Waters, Astrid Weber, Diana Wellesley, Margo Whiteford, Sara Widaa, Sarah Wilcox, Emily Wilkinson, Denise Williams, Nicola Williams, Louise Wilson, Geoff Woods, Christopher Wragg, Michael Wright, Laura Yates, Michael Yau, Chris Nellåker, Michael Parker, Helen V. Firth, Caroline F. Wright, David R. FitzPatrick, Jeffrey C. Barrett, and Matthew E. . Hurles

Subjects
0301 basic medicine, ASH1L, Male, Methyltransferase, Adolescent, Histone lysine methylation, KMT5B, Developmental Disabilities, Haploinsufficiency, Biology, Compound heterozygosity, histone lysine methyltransferase, Chromatin remodeling, chromatin remodeling, 03 medical and health sciences, histone lysine demethylase, Report, Genetics, Humans, Child, Genetics (clinical), Regulation of gene expression, Histone Demethylases, Developmental disorders, KMT2C, KMT2B, Histone-Lysine N-Methyltransferase, 030104 developmental biology, Histone, Overgrowth syndrome, Child, Preschool, Mutation, biology.protein, KDM5B, Female
Abstract

Histone lysine methyltransferases (KMTs) and demethylases (KDMs) underpin gene regulation. Here we demonstrate that variants causing haploinsufficiency of KMTs and KDMs are frequently encountered in individuals with developmental disorders. Using a combination of human variation databases and existing animal models, we determine 22 KMTs and KDMs as additional candidates for dominantly inherited developmental disorders. We show that KMTs and KDMs that are associated with, or are candidates for, dominant developmental disorders tend to have a higher level of transcription, longer canonical transcripts, more interactors, and a higher number and more types of post-translational modifications than other KMT and KDMs. We provide evidence to firmly associate KMT2C, ASH1L, and KMT5B haploinsufficiency with dominant developmental disorders. Whereas KMT2C or ASH1L haploinsufficiency results in a predominantly neurodevelopmental phenotype with occasional physical anomalies, KMT5B mutations cause an overgrowth syndrome with intellectual disability. We further expand the phenotypic spectrum of KMT2B-related disorders and show that some individuals can have severe developmental delay without dystonia at least until mid-childhood. Additionally, we describe a recessive histone lysine-methylation defect caused by homozygous or compound heterozygous KDM5B variants and resulting in a recognizable syndrome with developmental delay, facial dysmorphism, and camptodactyly. Collectively, these results emphasize the significance of histone lysine methylation in normal human development and the importance of this process in human developmental disorders. Our results demonstrate that systematic clinically oriented pathway-based analysis of genomic data can accelerate the discovery of rare genetic disorders.

Published
2017
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12. Effect of codon-optimized E. coli signal peptides on recombinant Bacillus stearothermophilus maltogenic amylase periplasmic localization, yield and activity

Author

Ganesh Sambasivam, Sunilkumar Sukumaran, Subbulakshmi Karthikeyan, Gunja Gupta, Ayyappan Nair, Saiful F. Haq, and Shalaka Samant

Subjects
Signal peptide, Glycoside Hydrolases, Recombinant Fusion Proteins, Gene Expression, Bioengineering, Protein Sorting Signals, Protein Engineering, medicine.disease_cause, Applied Microbiology and Biotechnology, law.invention, Geobacillus stearothermophilus, Bacterial Proteins, law, Escherichia coli, medicine, Amylase, Codon, biology, Protein engineering, Periplasmic space, Protein Transport, Secretory protein, Biochemistry, Codon usage bias, Periplasm, biology.protein, Recombinant DNA, Biotechnology
Abstract

Recombinant proteins can be targeted to the Escherichia coli periplasm by fusing them to signal peptides. The popular pET vectors facilitate fusion of target proteins to the PelB signal. A systematic comparison of the PelB signal with native E. coli signal peptides for recombinant protein expression and periplasmic localization is not reported. We chose the Bacillus stearothermophilus maltogenic amylase (MA), an industrial enzyme widely used in the baking and brewing industry, as a model protein and analyzed the competence of seven, codon-optimized, E. coli signal sequences to translocate MA to the E. coli periplasm compared to PelB. MA fusions to three of the signals facilitated enhanced periplasmic localization of MA compared to the PelB fusion. Interestingly, these three fusions showed greatly improved MA yields and between 18- and 50-fold improved amylase activities compared to the PelB fusion. Previously, non-optimal codon usage in native E. coli signal peptide sequences has been reported to be important for protein stability and activity. Our results suggest that E. coli signal peptides with optimal codon usage could also be beneficial for heterologous protein secretion to the periplasm. Moreover, such fusions could even enhance activity rather than diminish it. This effect, to our knowledge has not been previously documented. In addition, the seven vector platform reported here could also be used as a screen to identify the best signal peptide partner for other recombinant targets of interest.

Published
2014
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13. The Bacillus anthracis protein MprF is required for synthesis of lysylphosphatidylglycerols and for resistance to cationic antimicrobial peptides

Author

Fong-Fu Hsu, Alexander A. Neyfakh, Hyunwoo Lee, and Shalaka Samant

Subjects
Molecular Biology of Pathogens, Innate immune system, biology, Lysine, Virulence, Phosphatidylglycerols, Gene Expression Regulation, Bacterial, biology.organism_classification, Antimicrobial, Microbiology, Phagolysosome, Complement system, Bacillus anthracis, Bacterial Proteins, Genes, Bacterial, Drug Resistance, Bacterial, Protamines, Molecular Biology, Pathogen, Bacteria, Gene Deletion, Antimicrobial Cationic Peptides
Abstract

Bacillus anthracis is an endospore-forming gram-positive pathogen that causes the infectious disease anthrax in mammals, including humans. Infections can occur via intradermal inoculation, ingestion, or inhalation of spores (24). Although anthrax infections via the former two routes are usually self-contained, inhalational anthrax is often lethal (23). In a mouse model of inhalational anthrax, inhaled B. anthracis spores are phagocytosed by alveolar macrophages that are believed to migrate to local lymph nodes (10). During migration, the spores germinate inside the macrophage phagolysosome to give rise to vegetative bacilli. The newly formed vegetative cells lyse the phagolysosome and replicate inside the macrophage cytoplasm (6), eventually escaping from the macrophage into the bloodstream. Therefore, in order to establish a successful anthrax infection, B. anthracis must survive and replicate intracellularly inside the macrophage, as well as extracellularly in the host's blood. Upon entering the bloodstream, B. anthracis is targeted by an array of innate immune mediators circulating in the host's blood, such as the complement proteins and cellular components such as neutrophils and platelets in humans. However, inhalational anthrax infection in animals is characterized by rapid progression into systemic bacteremia and the heavy growth of B. anthracis in the bloodstream (21). This observation indicates that B. anthracis is able not only to evade complement-mediated lysis and but also to resist the antibacterial activities of innate immune cells. One important antibacterial activity of innate immune cells in the human blood relies on the production of cationic antimicrobial peptides. These peptides are present in the cytosolic granules of neutrophils, eosinophils, and platelets and are released upon contact with bacterial pathogens (18). Cationic antimicrobial peptides interact electrostatically with negatively charged cell surface molecules, such as teichoic acids and phosphatidylglycerols of gram-positive bacteria, subsequently inducing disintegration of membrane structures and ultimately causing bacterial cell death (41). Some gram-positive pathogens, however, possess resistance mechanisms, by which they change cell surface properties and avoid killing by cationic antimicrobial peptides. For example, gram-positive pathogens, such as Staphylococcus aureus (29, 30), Listeria monocytogenes (1, 37), and Streptococcus pneumoniae (16), are able to be modify teichoic acids and phospholipids with d-alanine by DltABCD and l-lysine by MprF, respectively. Since these modifications contribute to a net positive charge on the cell surface, they are believed to facilitate repulsion of the cationic peptides. Identifying the B. anthracis genes that contribute to cationic peptide resistance can elucidate the molecular basis of this virulence trait. A recent study has shown that the B. anthracis genome contains a functional dltABCD operon (7). A B. anthracis mutant strain inactivated in this operon exhibits hypersusceptibility to various cationic antimicrobial peptides, decreased survival in macrophages, and virulence attenuation in a mouse model of inhalational infection. To date, the dltABCD operon is the only genetic determinant of B. anthracis experimentally proven to contribute to cationic antimicrobial peptide resistance. In the present study, we have identified a B. anthracis gene (BA1486 in the ΔANR [pXO1−, pXO2−] strain; BAS1375 in the Sterne 34F2 [pXO1+, pXO2−] strain) whose knockout leads to hypersusceptibility to protamine, as well as to human cationic antimicrobial peptides, α-helical LL-37, and β-sheet human neutrophil peptide 1 (HNP-1). We show that inactivation of this gene results in a strain that is unable to synthesize phosphatidylglycerols modified with lysine. Our results demonstrate that the B. anthracis genome carries a functional mprF gene required for cationic antimicrobial peptide resistance.

Published
2008

14. Nucleotide Biosynthesis Is Critical for Growth of Bacteria in Human Blood

Author

Alexander A. Neyfakh, Alexander S. Mankin, James L. Cook, Hyunwoo Lee, Shalaka Samant, Juan Chen, and Mahmood Ghassemi

Subjects
lcsh:Immunologic diseases. Allergy, Genetic Markers, Salmonella typhimurium, Cloning, Organism, Immunology, Mutant, Virulence, Bacteremia, Biology, medicine.disease_cause, Microbiology, 03 medical and health sciences, Mice, Blood serum, Bacterial Proteins, Virology, Genetics, medicine, Escherichia coli, Animals, Humans, Gene Silencing, Molecular Biology, Gene, Pathogen, lcsh:QH301-705.5, Escherichia coli Infections, 030304 developmental biology, 0303 health sciences, 030306 microbiology, Nucleotides, biology.organism_classification, Microarray Analysis, Metabolic pathway, Eubacteria, Disease Models, Animal, Infectious Diseases, lcsh:Biology (General), Genes, Bacterial, Bacillus anthracis, Mutation, Parasitology, Female, lcsh:RC581-607, Bacteria, Research Article
Abstract

Proliferation of bacterial pathogens in blood represents one of the most dangerous stages of infection. Growth in blood serum depends on the ability of a pathogen to adjust metabolism to match the availability of nutrients. Although certain nutrients are scarce in blood and need to be de novo synthesized by proliferating bacteria, it is unclear which metabolic pathways are critical for bacterial growth in blood. In this study, we identified metabolic functions that are essential specifically for bacterial growth in the bloodstream. We used two principally different but complementing techniques to comprehensively identify genes that are required for the growth of Escherichia coli in human serum. A microarray-based and a dye-based mutant screening approach were independently used to screen a library of 3,985 single-gene deletion mutants in all non-essential genes of E. coli (Keio collection). A majority of the mutants identified consistently by both approaches carried a deletion of a gene involved in either the purine or pyrimidine nucleotide biosynthetic pathway and showed a 20- to 1,000-fold drop in viable cell counts as compared to wild-type E. coli after 24 h of growth in human serum. This suggests that the scarcity of nucleotide precursors, but not other nutrients, is the key limitation for bacterial growth in serum. Inactivation of nucleotide biosynthesis genes in another Gram-negative pathogen, Salmonella enterica, and in the Gram-positive pathogen Bacillus anthracis, prevented their growth in human serum. The growth of the mutants could be rescued by genetic complementation or by addition of appropriate nucleotide bases to human serum. Furthermore, the virulence of the B. anthracis purE mutant, defective in purine biosynthesis, was dramatically attenuated in a murine model of bacteremia. Our data indicate that de novo nucleotide biosynthesis represents the single most critical metabolic function for bacterial growth in blood and reveal the corresponding enzymes as putative antibiotic targets for the treatment of bloodstream infections., Author Summary Bacterial growth in the bloodstream is a common manifestation of a number of bacterial infections. When growing in blood, bacteria not only have to evade the host's immune response, but also adjust their metabolism to suit availability of nutrients. Although the concentrations of various metabolites in human blood are known, it is difficult to predict which nutrients are abundant and which are scarce. To proliferate in human blood, bacteria need to synthesize metabolites that are present in the limiting concentrations. For that, they need to produce specific enzymes that are, thus, critical for the bacterial growth in the bloodstream. We carried out a comprehensive, genome-wide search for Escherichia coli genes that are essential for growth in human serum. We found that inactivation of nucleotide biosynthesis genes leads to a significant growth defect in human serum not only for E. coli but also for two other pathogens, Salmonella Typhimurium and Bacillus anthracis. The results of this study demonstrate that the limiting amounts of the nucleotide bases in human serum force invading pathogens to rely on de novo nucleotide biosynthesis. Hence, our findings reveal nucleotide biosynthesis enzymes as a possible target for the treatment of bloodstream infections.

Published
2008

15. The SANT2 domain of the murine tumor cell DnaJ-like protein 1 human homologue interacts with alpha1-antichymotrypsin and kinetically interferes with its serpin inhibitory activity

Author

Ebrahim C. Elguindi, Christina M. Evangelista, Shalaka Samant, Sylvie Y. Blond, and Barbara Kroczynska

Subjects
DNA, Complementary, alpha 1-Antichymotrypsin, Molecular Sequence Data, Serpin, Biochemistry, Alpha 1-antichymotrypsin, Article, Serine, Mice, Cell Line, Tumor, Animals, Humans, Amino Acid Sequence, Binding site, Cloning, Molecular, Molecular Biology, Peptide sequence, Endoplasmic Reticulum Chaperone BiP, Heat-Shock Proteins, Serpins, DNA Primers, chemistry.chemical_classification, Chymotrypsin, Binding Sites, biology, Base Sequence, Sequence Homology, Amino Acid, Membrane Proteins, Cell Biology, HSP40 Heat-Shock Proteins, Molecular biology, Kinetics, Enzyme, chemistry, biology.protein, Carrier Proteins, SANT domain
Abstract

The murine tumor cell DnaJ-like protein 1 or MTJ1/ERdj1 is a membrane J-domain protein enriched in microsomal and nuclear fractions. We previously showed that its lumenal J-domain stimulates the ATPase activity of the molecular chaperone BiP/GRP78 (Chevalier, M., Rhee, H., Elguindi, E. C., and Blond, S. Y. (2000) J. Biol. Chem. 275, 19620-19627). MTJ1/ERdj1 also contains a large carboxyl-terminal cytosolic extension composed of two tryptophan-mediated repeats or SANT domains for which the function(s) is unknown. Here we describe the cloning of the human homologue HTJ1 and its interaction with alpha(1)-antichymotrypsin (ACT), a member of the serine proteinase inhibitor (serpin) family. The interaction was initially identified in a two-hybrid screening and further confirmed in vitro by dot blots, native electrophoresis, and fluorescence studies. The second SANT domain of HTJ1 (SANT2) was found to be sufficient for binding to ACT, both in yeast and in vitro. Single tryptophan-alanine substitutions at two strictly conserved residues significantly (Trp-497) or totally (Trp-520) abolished the interaction with ACT. SANT2 binds to human ACT with an intrinsic affinity equal to 0.5 nm. Preincubation of ACT with nearly stoichiometric concentrations of SANT2 wild-type but not SANT2: W520A results in an apparent loss of ACT inhibitory activity toward chymotrypsin. Kinetic analysis indicates that the formation of the covalent inhibitory complex ACT-chymotrypsin is significantly delayed in the presence of SANT2 with no change on the catalytic efficiency of the enzyme. This work demonstrates for the first time that the SANT2 domain of MTJ1/HTJ1/ERdj1 mediates stable and high affinity protein-protein interactions.

Published
2003

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