Control of synaptic transmission by scaffold proteins. (360G-Wellcome-085510_Z_08_Z)

The aim of the first study is to determine if AKAP79/150 is involved in voltage-gated Ca2+ channel regulation in the SNc. AKAP79/150 anchors protein kinase A (PKA), protein kinase C (PKC) and protein phosphatase 2B (PP2B) for regulation of membrane proteins and receptors. Three lines of mice have been engineered with mutations in the AKAP79/150-binding sites for either PKA, PKC or PP2B. Measurements of pacemaking in the SNc in the different breeds of mice will be integrated with studies in cu ltured cells that will include simultaneous electrophysiological and time-lapse imaging recordings of voltage-gated Ca2+ channel signalling. A structural investigation of voltage-gated calcium channel signalling will be initiated in the last year of the fellowship. Both AKAP79/150 and certain members of the membrane-associated guanylate kinase (MAGUK) family can bind CaM and are present in the postsynaptic density (PSD). In this situtation they could potentially orchestrate a rewiring of si gnalling pathways in the PSD following Ca2+ influx and subsequent CaM activation. A second related study will aim to test this hypothesis. RNAi-based experiments in cultured cells will examine the effect of mutation of the CaM-binding site in AKAP79/150, and a proteomic/systems biology investigation to investigate whether CaM activation affects MAGUK valency.