Dr Nicolas Locker
Lecturer in Virology
Qualifications: PhD
Email: n.locker@surrey.ac.uk
Phone: Work: 01483 68 9719
Room no: 04 AX 01
Office hours
Meetings by appointment
Further information
Biography
2009-: Lecturer in Virology, University of Surrey, Guildford, UK
Viral RNA, Translation, Virus-host interactions2007-09: Post Doctoral Fellow, Université Paris Descartes, Paris, Fr
Dr Sargueil group: Viral RNA, HIV, translation2004-07: Post Doctoral Fellow, Laboratory of Molecular Biology, MRC Cambridge, UK
Dr Lukavsky group: Viral RNA, HCV, translation2003: PhD in Protein Engineering, Université Paris XI, Fr
Dr Guittet group: RNA, NMR structure and function, Institut de Chimie des Substances Naturelles, Gif, France2000: Master Degree in Molecular Biophysic, Université Paris VI, Fr
Research Interests
Background:
My previous research has focused on the molecular mechanisms by which viral RNAs modulates specific regulatory processes of Hepatitis C and Human Immunodeficiency Viruses life cycle. I set out to decipher the mechanism by which viral RNA elements, termed internal ribosome entry site (IRES), interact with the translation machinery to hijack cellular translation and trigger viral translation. To tackle these questions, I set up new biochemical tools to study translation in vitro. Using both biochemical and biophysical techniques, I unraveled the pathway of 80S ribosome formation mediated by the HCV IRES and shed light on a new, original, translation initiation mechanism used by lentiviruses to produce several isoforms of the Gag polyprotein.
Current project:
Based on previous experience about translational control mediated by viral RNAs, our goal is to screen, identify and characterize inhibitors of IRES-dependent translation. We will focus on viral RNAs relevant to human pathogenesis (HCV, HIV, picornaviruses).
In collaboration with other group from the University of Surrey (Pr Lisa Roberts) and collaborators at the Chang Gung University Taiwan (Pr Shin-Ru Shih), we will also investigate how cellular proteins can assist viral IRES RNAs in the takeover of the virus-infected cell translation machinery.
Other new exciting project includes the development of new assays to study virus-host interactions and studying translation control during SARS infection in collaboration with Pr Shinji Makino (UTMB).
Research Collaborations
Lisa Roberts, University of Surrey, Guildford UK
Bruno Sargueil, Université Paris Descartes, Paris Fr
Pr Yoon-Ki Kim, University of Korea, Seoul Kr
Shinji Makino, University of Texas Medical Branch, Galveston USA
Shin-Ru Shih, Chang-Gung University, Tao-Yuan Tw
Publications
Journal articles
- . (2012) 'Translation Initiation on mRNAs Bound by Nuclear Cap-binding Protein Complex CBP80/20 Requires Interaction between CBP80/20-dependent Translation Initiation Factor and Eukaryotic Translation Initiation Factor 3g'. AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC JOURNAL OF BIOLOGICAL CHEMISTRY, 287 (22), pp. 18500-18509.
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(2011) 'Far upstream element binding protein 1 binds the internal ribosomal entry site of enterovirus 71 and enhances viral translation and viral growth.'. Oxford University Press Nucleic Acids Res, , pp. 1-16.doi: 10.1093/nar/gkr682Full text is available at: http://epubs.surrey.ac.uk/184878/
Abstract
Enterovirus 71 (EV71) is associated with severe neurological disorders in children, and has been implicated as the infectious agent in several large-scale outbreaks with mortalities. Upon infection, the viral RNA is translated in a cap-independent manner to yield a large polyprotein precursor. This mechanism relies on the presence of an internal ribosome entry site (IRES) element within the 5'-untranslated region. Virus-host interactions in EV71-infected cells are crucial in assisting this process. We identified a novel positive IRES trans-acting factor, far upstream element binding protein 1 (FBP1). Using binding assays, we mapped the RNA determinants within the EV71 IRES responsible for FBP1 binding and mapped the protein domains involved in this interaction. We also demonstrated that during EV71 infection, the nuclear protein FBP1 is enriched in cytoplasm where viral replication occurs. Moreover, we showed that FBP1 acts as a positive regulator of EV71 replication by competing with negative ITAF for EV71 IRES binding. These new findings may provide a route to new anti-viral therapy.
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(2011) 'Structural Features of the Seneca Valley Virus Internal Ribosome Entry Site (IRES) Element: a Picornavirus with a Pestivirus-Like IRES'. AMER SOC MICROBIOLOGY JOURNAL OF VIROLOGY, 85 (9), pp. 4452-4461.doi: 10.1128/JVI.01107-10
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(2010) 'The different pathways of HIV genomic RNA translation'. PORTLAND PRESS LTD BIOCHEMICAL SOCIETY TRANSACTIONS, 38, pp. 1548-1552.doi: 10.1042/BST0381548
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(2010) 'A conserved structure within the HIV gag open reading frame that controls translation initiation directly recruits the 40S subunit and eIF3'. Nucleic Acids Research, 39 (6), pp. 2367-2377.doi: 10.1093/nar/gkq1118Full text is available at: http://epubs.surrey.ac.uk/184879/
Abstract
Translation initiation on HIV genomic RNA relies on both cap and Internal Ribosome Entry Site (IRES) dependant mechanisms that are regulated throughout the cell cycle. During a unique phenomenon, the virus recruits initiation complexes through RNA structures located within Gag coding sequence, downstream of the initiation codon. We analyzed initiation complexes paused on the HIV-2 gag IRES and revealed that they contain all the canonical initiation factors except eIF4E and eIF1. We report that eIF3 and the small ribosomal subunit bind HIV RNA within gag open reading frame. We thus propose a novel two step model whereby the initial event is the formation of a ternary eIF3/40S/IRES complex. In a second step, dependent on most of the canonical initiation factors, the complex is rearranged to transfer the ribosome on the initiation codons. The absolute requirement of this large structure for HIV translation defines a new function for a coding region. Moreover, the level of information compaction within this viral genome reveals an additional level of evolutionary constraint on the coding sequence. The conservation of this IRES and its properties in rapidly evolving viruses suggest an important role in the virus life cycle and highlight an attractive new therapeutic target.
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(2009) 'Conserved functional domains and a novel tertiary interaction near the pseudoknot drive translational activity of hepatitis C virus and hepatitis C virus-like internal ribosome entry sites'. OXFORD UNIV PRESS NUCLEIC ACIDS RESEARCH, 37 (16), pp. 5537-5549.doi: 10.1093/nar/gkp588
• Locker N, Easton LE and Lukavsky PJ (2007) HCV and CSFV IRES domain II mediate eIF2 release during 80S ribosome assembly. EMBO Journal, 26: 795-805.
• ElAntak L, Tzakos AG, Locker N and Lukavsky PJ (2007) Structure of eIF3b-RRM and its interaction with eIF3j, structural insights into the recruitment of eIF3 to the 40S ribosomal subunit. Journal of Biochemical Chemistry, 282: 8165-74.
• Locker N and Lukavsky PJ (2007) A practical approach to isolate 48S complexes: Affinity purification and analyses. Methods in Enzymology, 429 :83-104.
• Locker N, Easton LE and Lukavsky PJ (2006) Affinity purification of eukaryotic 48S initiation complexes. RNA, 12: 683-690.
• Hallay H§, Locker N§, Ayadi L, Ropers D, Guittet E and Branlant C (2006) Biochemical and NMR study on the competition between proteins SC35 Srp40 and hnRNP A1 at the HIV-1 tat exon 2 splicing site. Journal of Biochemical Chemistry, 281: 37159-37174.
Teaching
BMS2037: Cellular Microbiology and Virology
BMS3053: Molecular Biology and Genetics 3
BMS3061: Pathogenesis of Infectious Disease (Coordinator)
BMS3073: Epidemiology, Control and Treatment of Infectious Disease
MMIM015: Virology (Coordinator)
lectures notes
