Cav2 Nano-Environments

Quantitative proteomics of the Cav2 channel nano-environments in the mammalian brain

http://dx.doi.org/10.1073/pnas.1005940107

Local Ca2+ signaling occurring within nanometers of voltage-gated Ca2+ (Cav) channels is crucial for CNS function, yet the molecular composition of Cav channel nano-environments is largely unresolved. Here we employed a novel proteomic strategy combining knockout-controlled multi-epitope affinity purifications with high-resolution quantitative mass spectrometry for comprehensive analysis of the molecular nano-environments of the Cav2 channel family in the whole rodent brain. The analysis shows that Cav2 channels, composed of pore-forming alpha-1 and auxiliary beta subunits, are embedded into protein networks that may be assembled from a pool of ~200 proteins with distinct abundance, stability of assembly and preference for the three Cav2 subtypes. The majority of these proteins have not previously been linked to Cav channels. The identified protein networks reflect the cellular processes that can be initiated by Cav2 channel activity and define the molecular framework for organization and operation of local Ca2+-signaling by Cav2 channels in the brain.