Single plasma membrane K+ channel detection by using dual-color quantum dot labeling.
K+ channels are widely expressed in eukaryotic and prokaryotic cells, where one of their key functions is to set the membrane potential. Many K+ channels are tetramers that share common architectural properties. The crystal structure of bacterial and mammalian K+ channels has been resolved and provides the basis for modeling their three-dimensional structure in different functional states. This wealth of information on K+ channel structure contrasts with the difficulties to visualize single K+ channel proteins in their physiological environment. We describe a method to identify single Ca2+-activated K+ channel molecules in the plasma membrane of migrating cells. Our method is based on dual-color labeling with quantum dots. We show that >90% of the observed quantum dots correspond to single K+ channel proteins. We anticipate that our method can be adopted to label any other ion channel in the plasma membrane on the single molecule level.
Institute of Physiology II, Univ. of Münster, Robert-Koch-Strasse 27b, D-48149 Münster, Germany.
Volodymyr
V
Nechyporuk-Zloy
Christian
C
Stock
Hermann
H
Schillers
Hans
H
Oberleithner
Albrecht
A
Schwab
D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism* / Q000648:ultrastructure*; D004285:Dogs; D007668:Kidney / Q000378:metabolism* / Q000648:ultrastructure*; D008832:Microchemistry / Q000379:methods; D036641:Microscopy, Fluorescence, Multiphoton / Q000379:methods*; D024681:Potassium Channels, Calcium-Activated / Q000378:metabolism* / Q000648:ultrastructure*; D045663:Quantum Dots; D013194:Staining and Labeling / Q000379:methods
D024681:Potassium Channels, Calcium-Activated