Chemical Pathology

General Information

Professor G G Brownlee FRS is head of the Chemical Pathology Unit within the Sir William Dunn School of Pathology. The Unit has expertise in molecular biology, cell biology and gene regulation. At present the Unit includes, besides Professor Brownlee's research group, the groups of Professor N J Proudfoot, Dr S Murphy (MRC Senior Research Fellow) and Dr E Fodor (MRC Senior Research Fellow). There are about 40 staff (postdocs, DPhil students and technicians). Each year 3-4 DPhil students sponsored by the MRC, BBSRC or the Wellcome Trust enter the Unit. Mrs Joanne Collett is PA to Professor Brownlee and the Unit.

Professor G G Brownlee

Tel +44 (0)1865 275559

Fax +44 (0)1865 275556

EMail george.brownlee@path.ox.ac.uk

Mrs J Collett (PA)

Tel +44(0)1865 275558

Fax +44(0)1865 275556

EMail joanne.collett@path.ox.ac.uk

Professor Brownlee's research group (currently 4 postdocs, 2 DPhil students, 1 research assistant)

Our major interest is to study the control of transcription and replication of influenza virus (supported by a MRC Programme grant). We are also part of a MRC-supported Co-operative Group entitled “Basic mechanisms controlling gene expression”. The other principal investigators are Professor N J Proudfoot, Professor J Errington, Dr S Murphy and Dr E Fodor. A research assistant has been awarded to support the Co-operative Group as a whole.

Highlights of progress and current work now follows.

KEYWORDS: gene regulation, transcription, polyadenylation, replication, influenza virus

Transcription and replication of the 8 negative-sense RNA gene segments of influenza viruses is tightly controlled during infection. However, knowledge of the precise mechanism whereby the influenza RNA promoter controls transcription and replication has proved elusive. We and others have made considerable progress in understanding the nature of the secondary structure of the negative-sense virion RNA (vRNA) promoter (formed by the 5' and 3' ends of the vRNA segments) on the endonuclease and transcriptional activities of the influenza RNA polymerase.

An important and exciting advance is our ability to rescue influenza virus entirely from recombinant DNA without requiring a helper virus. This technological advance, presently in use in my laboratory, is aimed at a detailed understanding of the function of individual amino acids in the 3 subunits (PB1, PB2 and PA) of the influenza RNA-dependent RNA polymerase. The aim of present and future work is to solve the molecular basis of how the polymerase switches from transcription to replication by initiating structural, and continuing our functional studies of recombinant polymerase. Structural studies of the RNA polymerase are ongoing in collaboration with Professor D Stuart (Oxford).

References

1. Leahy MB, Pritlove DC, Poon LLM and Brownlee GG (2001). Mutagenic analysis of the 5' arm of the influenza A virus virion RNA promoter defines the sequence requirements for endonuclease activity. J. Virol. , 75: 134-142.

2. Leahy MB, Dobbyn HC and Brownlee GG (2001). A hairpin loop structure in the 3' arm of the influenza A virus virion RNA promoter is required for endonuclease activity. J. Virol. 75: 7042-7049.

3. Brownlee GG and Fodor E (2001). The predicted antigenicity of the haemagglutinin of the 1918 Spain influenza suggests an avian origin. Phil. Trans. Roy. Soc. Lond. B 356: 1871-1876.

4. Leahy MB, Zecchin G and Brownlee GG (2002). Differential activation of influenza A virus endonuclease activity is dependent on multiple sequence differences between the virion RNA and cRNA promoters. J. Virol., 76: 2019-2023.

5. Brownlee GG and Sharps JL (2002). The RNA polymerase of influenza A virus is stabilised by interaction with its viral RNA promoter. J. Virol., 76: 7103-7113.`

6. Fodor E and Brownlee GG (2002). Influenza virus replication (review). In “Influenza” (Potter CW, Ed) in series "Perspectives in Medical Virology" (Zuckerman AJ and Mushawar LK, Eds), Elsevier Science, Amsterdam. p 1-29.

7. Fodor E, Crow M, Mingay LJ, Deng T, Sharps J, Fechter P and Brownlee GG (2002). A single amino acid mutation in the PA subunit of the influenza RNA polymerase inhibits endonucleolytic cleavage of capped RNAs. J Virol., 76: 8989-9001

8. Subbarao K, Chen H, Swayne D, Mingay L, Fodor E, Brownlee G, Xu X, Lu X, Katz J, Cox N and Matsuoka Y (2003). Evaluation of a genetically modified reassortant H5N1 influenza A virus vaccine candidate generated by plasmid-based reverse genetics. Virology, 305: 192-200.

9. Catchpole AP, Mingay LJ, Fodor E and Brownlee GG (2003). Alternative base pairs attenuate influenza A virus when introduced into the duplex region of the conserved viral RNA promoter of either the NS or the PA gene. J. Gen. Virol., 84: 507-515.

10. Fodor E, Mingay LJ, Crow M, Deng T and Brownlee GG (2003). A single amino acid mutation in the PA subunit of the influenza RNA polymerase promotes the generation of defective interfering RNAs. J. Virol., 77: 5017-5020

11. Fechter P, Mingay L, Sharps J, Chambers A, Fodor E and Brownlee GG (2003). Two aromatic residues in the PB2 subunit of influenza A RNA polymerase are crucial for cap-binding. J. Biol. Chem., 278: 20381-20388.

12. Neumann G, Brownlee GG, Fodor E and Kawaoka Y (2004). Orthomyxovirus Replication, Transcription, and Polyadenylation. In “Biology of Negative Strand RNA viruses: The Power of Reverse Genetics” (Springer Verlag Berlin Heidelberg New York – ed. Y Kawaoka) 121-143.

13. Crow M, Deng T, Addley M and Brownlee GG (2004). Mutational analysis of the influenza cRNA promoter and identification of nucleotides critical for replication. J. Virol. 78: 6263-6270.

14. Vreede FT, Jung TE and Brownlee GG (2004). Model suggesting that replication of influenza virus is regulated by stabilization of replicative intermediates. J. Virol. 78: 9568-9572.

15. Fodor E, Fechter P, Crow M. Deng T, Mingay L, Sharps J and Brownlee GG, (2004) Mutational analysis of the PA and PB2 subunits of the influenza RNA polymerase complex leads to new insights into function. In “Options for the Control of Influenza V” (Y Kawaoka, Ed), Elsevier Science, Amsterdam. International Congress Series 1263: 25-28

16. Fechter P and Brownlee GG (2005). Recognition of mRNA cap structures by viral and cellular proteins. J. Gen. Virol. 86: 1239-1249

17. Deng T, Sharps J, Fodor E and Brownlee GG (2005). In vitro assembly of PB2 with a PB1-PA dimer supports a new model of assembly of influenza A virus polymerase subunits into a functional trimeric complex. J. Virol. 79: 8669-8674

18. Carr SM, Carnero E, Garcia-Sastre A, Brownlee GG, Fodor E (2005). Characterization of a mitochondrial-targeting signal in the PB2 protein of influenza viruses. Virology, 344: 492-508

19. Jung, TE and Brownlee GG (2006). A new promoter binding site in the PB1 subunit of the influenza A virus polymerase. J. Gen. Virol, 87: 679-688

20. Deng T, Vreede F and Brownlee GG (2006). Different de novo initiation strategies are used by influenza virus RNA polymerase on its cRNA and vRNA promoters during viral RNA replication. J. Virol. 80: 2337-48