RT Journal Article
SR Electronic
T1 G-Protein-Coupled Receptor Modulation of Striatal Ca<sub>V</sub>1.3 L-Type Ca<sup>2+</sup> Channels Is Dependent on a Shank-Binding Domain
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 1050
OP 1062
DO 10.1523/JNEUROSCI.3327-04.2005
VO 25
IS 5
A1 Patricia A. Olson
A1 Tatiana Tkatch
A1 Salvador Hernandez-Lopez
A1 Sasha Ulrich
A1 Ema Ilijic
A1 Enrico Mugnaini
A1 Hua Zhang
A1 Ilya Bezprozvanny
A1 D. James Surmeier
YR 2005
UL http://www.jneurosci.org/content/25/5/1050.abstract
AB Voltage-gated L-type Ca2+ channels are key determinants of synaptic integration and plasticity, dendritic electrogenesis, and activity-dependent gene expression in neurons. Fulfilling these functions requires appropriate channel gating, perisynaptic targeting, and linkage to intracellular signaling cascades controlled by G-protein-coupled receptors (GPCRs). Surprisingly, little is known about how these requirements are met in neurons. The studies described here shed new light on how this is accomplished. We show that D2 dopaminergic and M1 muscarinic receptors selectively modulate a biophysically distinctive subtype of L-type Ca2+ channels (CaV1.3) in striatal medium spiny neurons. The splice variant of these channels expressed in medium spiny neurons contains cytoplasmic Src homology 3 and PDZ (postsynaptic density-95 (PSD-95)/Discs large/zona occludens-1) domains that bind the synaptic scaffolding protein Shank. Medium spiny neurons coexpressed CaV1.3-interacting Shank isoforms that colocalized with PSD-95 and CaV1.3a channels in puncta resembling spines on which glutamatergic corticostriatal synapses are formed. The modulation of CaV1.3 channels by D2 and M1 receptors was disrupted by intracellular dialysis of a peptide designed to compete for the CaV1.3 PDZ domain but not with one targeting a related PDZ domain. The modulation also was disrupted by application of peptides targeting the Shank interaction with Homer. Upstate transitions in medium spiny neurons driven by activation of glutamatergic receptors were suppressed by genetic deletion of CaV1.3 channels or by activation of D2 dopaminergic receptors. Together, these results suggest that Shank promotes the assembly of a signaling complex at corticostriatal synapses that enables key GPCRs to regulate L-type Ca2+ channels and the integration of glutamatergic synaptic events.