The effect of agonist activation and homodimerisation on the membrane diffusion of the human histamine H1 receptor

There is considerable evidence to support the existence of dimers of class A G-protein-coupled receptors, including the histamine H1 receptor (H1R) (Bakker et al, 2004), although the functional significance of these dimers remains unclear. We have used bimolecular fluorescence complementation (BiFC) in combination with fluorescence correlation spectroscopy (FCS) to selectively monitor histamine-mediated changes in the diffusion characteristics of the dimeric human H1R (using BiFC), as well as those of the total H1R population (using labelling with the full length yellow fluorescent protein (YFP)).