C2-domain mediated nano-cluster formation increases calcium signaling efficiency.
Conventional protein kinase Cs (cPKCs) are key signaling proteins for transducing intracellular Ca2+signals into downstream phosphorylation events. However, the lifetime of individual membrane-bound activated cPKCs is an order of magnitude shorter than the average time needed for target-protein phosphorylation. Here, we employed intermolecular Förster resonance energy transfer (FRET) in living cells combined with computational analysis to study the spatial organization of cPKCs bound to the plasma membrane. We discovered Ca2+-dependent cPKC nano-clusters that significantly extend cPKC's plasma-membrane residence time. These protein patterns resulted from self-assembly mediated by Ca2+-binding C2-domains, which are widely used for membrane-targeting of Ca2+-sensing proteins. We also established clustering of other unrelated C2-domain containing proteins, suggesting that nano-cluster formation is a key step for efficient cellular Ca2+-signaling.
Theoretical Physics, Saarland University, Saarbrücken, Germany.
Mike
M
Bonny
Institute for Molecular Cell Biology, Medical Faculty, Saarland University, Homburg/Saar, Germany.
Xin
X
Hui
Institute for Molecular Cell Biology, Medical Faculty, Saarland University, Homburg/Saar, Germany.
Julia
J
Schweizer
Institute for Molecular Cell Biology, Medical Faculty, Saarland University, Homburg/Saar, Germany.
Lars
L
Kaestner
Cellular Neurophysiology, Center of Physiology, Hannover Medical School, Hannover, Germany.
André
A
Zeug
Theoretical Physics, Saarland University, Saarbrücken, Germany.
Karsten
K
Kruse
Institute for Molecular Cell Biology, Medical Faculty, Saarland University, Homburg/Saar, Germany.
Peter
P
Lipp
D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling; D002462:Cell Membrane / Q000201:enzymology; D003198:Computer Simulation; D031541:Fluorescence Resonance Energy Transfer; D057809:HEK293 Cells; D006801:Humans; D046911:Macromolecular Substances / Q000378:metabolism; D053758:Nanoparticles / Q000737:chemistry*; D000072417:Protein Domains; D051571:Protein Kinase C-alpha / Q000737:chemistry* / Q000378:metabolism*; D013269:Stochastic Processes; D013329:Structure-Activity Relationship; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D046911:Macromolecular Substances; D051571:Protein Kinase C-alpha; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium