Quantitative proteomics of the Cav2 channel nano-environments in the mammalian brain.
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.
Müller
Catrin Swantje
CS
Institute of Physiology II, University of Freiburg, 79108 Freiburg, Germany.
Haupt
Alexander
A
Bildl
Wolfgang
W
Schindler
Jens
J
Knaus
Hans-Günther
HG
Meissner
Marcel
M
Rammner
Burkhard
B
Striessnig
Jörg
J
Flockerzi
Veit
V
Fakler
Bernd
B
Schulte
Uwe
U
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
D015220:Calcium Channels; D046912:Multiprotein Complexes; D021122:Protein Subunits; D020543:Proteome