Research Interests and Techniques

The main theme underlying my research is purinergic signalling in the cardiovascular system. As well as their obvious roles in cell metabolism, nucleotides also act as extracellular signalling molecules via ionotropic P2X and metabotropic P2Y receptors. These receptors mediate a wide variety of important cardiovascular functions including platelet aggregation, vasoconstriction/dilation and cardiac contractility. The expression patterns of P2 receptors show both spatial and temporal distributions and I am interested in determining the gene regulation mechanisms underlying this control in P2X receptors. I am also interested in relating the structure of the P2X receptors to their function as ion channels and in investigating interactions between P2 receptors and other proteins.

Techniques

General molecular biology (Cloning, RT-PCR, mutagenesis, In situ and Northern hybridisations, cell culture and reporter gene expression analysis)
Protein expression (Western Blots, immunohistochemistry, determining cell surface expression levels of receptors by biotinylation)
Electrophysiology (Xenopus oocyte expression system and two electrode voltage clamp)

Research Group and Funding

Present members

Mr Selvan Bavan

Current funding

BBSRC Transcriptional control mechanisms in the human P2X1 and P2X3 genes
BBSRC Study of Dictyostelium P2X function

Recent Publications

Zhao J, Ennion SJ. (2006) Sp1/3 and NF-1 mediate basal transcription of the human P2X1 gene in megakaryoblastic MEG-01 cells. BMC Mol Biol. 7:10.

Atkinson PJ, Young KW, Ennion SJ, Kew JN, Nahorski SR, Challiss RA. (2005) Altered expression of G(q/11alpha) protein shapes mGlu1 and mGlu5 receptor-mediated single cell inositol 1,4,5-trisphosphate and Ca(2+) signaling. Mol Pharmacol. 69(1):174-84

Agboh KC, Webb TE, Evans RJ, and Ennion SJ. (2004) Functional characterisation of a P2X receptor from schistosoma mansoni. Journal of Biological Chemistry 279(40): p. 41650-41657

Ennion SJ, Powell AD, Seward EP. (2004) Identification of the P2Y12 receptor in nucleotide inhibition of exocytosis from bovine chromaffin cells. Molecular Pharmacology. 66: 601-611.

Ennion SJ and Evans RJ (2002) P2X(1) receptor subunit contribution to gating revealed by a dominant negative PKC mutant. Biochem Biophys Res Commun. 291(3):611-6.

Ennion SJ and Evans RJ. (2002) The role of cysteine residues and disulphide bond formation in the human P2X1 receptor. Molecular Pharmacology 61(2):303-11.

Ennion SJ, Ritson J, Evans RJ. (2001) Conserved negatively charged residues are not required for ATP action at P2X(1) receptors. Biochem Biophys Res Commun. 289, 700-704.

Ennion SJ and Evans RJ. (2001) Agonist-stimulated internalisation of the ligand-gated ion channel P2X1 in rat vas deferens. FEBS Letters. 489, 154-158.

Ennion SJ, Hagan S, Evans RJ. (2000). The role of positively charged amino acids in ATP recognition by human P2X1 receptors. Journal of Biological Chemistry. 275, 29361-7.