Aim:
1. To determine the impact of β-arrestin/G protein deficiency on CXCR4/ CXCR7, or heteromer function and signalling.

2. To analyze the efficacy of CXCR4 and CXCR7 modulators in G protein and β-arrestin-dependent pathways using label free technologies.

Methodology:
This project will capitalise on the availability, to our group, of a unique cellular resource allowing for conditional, and selective, expression of β-arrestin proteins in HEK cells. These cells will be transfected with CXCR4 and/or CXCR7 and signalling output and hetero/homodimeristion assessed in the presence, or absence, of arrestin expression. Receptor dimerisation will be examined (in the presence or absence of arrestin expression) using FRET-based approaches. These cells will also be used to test the effects of co-expression of CXCR4 and CXCR7 on directional cellular migration using time-lapse migration assays and, again, the dependence of these effects on arrestin signalling will be investigated. If time permits, we will also use these approaches to analyse the β-arrestin dependency of signalling and function in other members of the Atypical Chemokine receptor family. Planned secondments: UAM (ES), Cisbio (FR).

Required diploma: MSc degree in a relevant biological science. Candidates with degrees in biochemistry or pharmacology are particularly encouraged to apply.

Required expertise: Biochemistry, molecular biology, cell culture.

Recommended expertise: Chemokine biology, GPCR biochemistry, protein chemistry.

Key publications:
1. Nibbs RJB, Graham GJ: Immune regulation by atypical chemokine receptors, Nature Reviews Immunology 2013, 13:815-829.

2. Lee KM, Danuser R, Stein JV, Graham D, Nibbs RJB, Graham GJ. The chemokine receptors ACKR2 and CCR2 reciprocally regulate lymphatic vessel density. The EMBO Journal 2014, 33, 2564-2580

3. Butcher, A.J., Hudson, B.D., Shimpukade, B., Alvarez-Curto, E., Prihandoko, R., Ulven, T., Milligan, G. and Tobin, A.B. (2014) Concomitant action of structural elements and receptor phosphorylation determine arrestin-3 interaction with the free fatty acid receptor FFA4. J Biol Chem 289, 18451-18465

4. Hudson, B.D., Christiansen, E., Murdoch, H., Jenkins, L., Højgaard Hansen, A., Madsen, O., Ulven, T. and Milligan, G. (2014) Complex pharmacology of novel allosteric Free Fatty Acid 3 Receptor ligands. Mol Pharmacol 86, 200-210.