title: Quantitative proteomics of the Cav2 channel nano-environments in the mammalian brain.
abstract: Local Ca(2+) signaling occurring within nanometers of voltage-gated Ca(2+) (Cav) channels is crucial for CNS function, yet the molecular composition of Cav channel nano-environments is largely unresolved. Here, we used a proteomic strategy combining knockout-controlled multiepitope affinity purifications with high-resolution quantitative MS 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 alpha1 and auxiliary beta subunits, are embedded into protein networks that may be assembled from a pool of approximately 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; about two-thirds are dedicated to the control of intracellular Ca(2+) concentration, including G protein-coupled receptor-mediated signaling, to activity-dependent cytoskeleton remodeling or Ca(2+)-dependent effector systems that comprise a high portion of the priming and release machinery of synaptic vesicles. 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 Ca(2+) signaling by Cav2 channels in the brain.
authors.affiliation: Institute of Physiology II, University of Freiburg, 79108 Freiburg, Germany.
authors.forename: Catrin Swantje
authors.initials: CS
authors.lastname: Müller
authors.forename: Alexander
authors.initials: A
authors.lastname: Haupt
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Bildl
authors.forename: Jens
authors.initials: J
authors.lastname: Schindler
authors.forename: Hans-Günther
authors.initials: HG
authors.lastname: Knaus
authors.forename: Marcel
authors.initials: M
authors.lastname: Meissner
authors.forename: Burkhard
authors.initials: B
authors.lastname: Rammner
authors.forename: Jörg
authors.initials: J
authors.lastname: Striessnig
authors.forename: Veit
authors.initials: V
authors.lastname: Flockerzi
authors.forename: Bernd
authors.initials: B
authors.lastname: Fakler
authors.forename: Uwe
authors.initials: U
authors.lastname: Schulte
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000378:metabolism*; D015220:Calcium Channels / Q000737:chemistry / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D020013:Calcium Signaling; D066298:In Vitro Techniques; D051379:Mice; D018345:Mice, Knockout; D008958:Models, Molecular; D008969:Molecular Sequence Data; D046912:Multiprotein Complexes; D055550:Protein Stability; D021122:Protein Subunits; D020543:Proteome; D040901:Proteomics / Q000379:methods; D051381:Rats
chemical_list: D015220:Calcium Channels; D046912:Multiprotein Complexes; D021122:Protein Subunits; D020543:Proteome