Quantifying the interaction of the C-terminal regions of polycystin-2 and polycystin-1 attached to a lipid bilayer by means of QCM.
The pkd1 and pkd2 genes encode for the proteins polycystin-1 (PC1) and polycystin-2 (PC2). These genes are mutated in patients diagnosed with autosomal dominant polycystic kidney disease. PC1 and PC2 interact via their C-terminal, cytosolic regions, which is an essential step in the regulation of cell proliferation and differentiation. Here, we developed an assay that allowed us to quantitatively monitor the interaction of the C-terminal region of PC1 (cPC1) with that of PC2 (cPC2) to be able to answer the question of how Ca(2+) influences the PC1/PC2 complex formation. By means of the quartz crystal microbalance (QCM) technique, we were able to determine binding affinities and kinetic constants of the cPC1/cPC2 interaction using a model based on the scaled particle theory. The results suggest that cPC2 forms trimers in solution in the absence of Ca(2+), which bind in a one step process to cPC1.
Behn
Daniela
D
Institut für Organische und Biomolekulare Chemie, Georg-August Universität, Tammannstr. 2, 37077 Göttingen, Germany.
Bosk
Sabine
S
Hoffmeister
Helen
H
Janshoff
Andreas
A
Witzgall
Ralph
R
Steinem
Claudia
C
D000327:Adsorption; D001703:Biophysics / Q000295:instrumentation* / Q000379:methods; D002118:Calcium / Q000378:metabolism; D004867:Equipment Design; D006801:Humans; D055767:Immobilized Proteins / Q000737:chemistry / Q000378:metabolism; D008051:Lipid Bilayers / Q000378:metabolism*; D008954:Models, Biological; D016891:Polycystic Kidney, Autosomal Dominant / Q000378:metabolism*; D011485:Protein Binding; D055503:Protein Multimerization; D011791:Quartz / Q000737:chemistry; D050396:TRPP Cation Channels / Q000737:chemistry / Q000378:metabolism*
D002118:Calcium; D055767:Immobilized Proteins; D008051:Lipid Bilayers; D011791:Quartz; D050396:TRPP Cation Channels