Dynamic cellular translocation of caldendrin is facilitated by the Ca2+-myristoyl switch of recoverin.
Caldendrin and recoverin are Ca(2+)-sensor proteins operating in neuronal systems. In a search for novel binding partners of recoverin, we employed an affinity column and identified caldendrin as a possible interaction partner. Caldendrin and recoverin co-localized in the retina in a subset of bipolar cells and in the pineal gland as revealed by immunofluorescence studies. The binding process was controlled by Ca(2+) as revealed by pull-down assays, and surface plasmon resonance studies. Importantly, caldendrin existed as a Ca(2+)-independent homodimer whereas a complex of recoverin and caldendrin formed with low to moderate affinity in the presence of Ca(2+). Co-transfection of COS-7 cells with plasmids harboring the gene for fluorescently labeled recoverin and caldendrin was used to study the cellular distribution by time-lapse fluorescence microscopy. Apparently, the increase of intracellular Ca(2+) facilitates the translocation of caldendrin to intracellular membranes, which is under control of complex formation with recoverin.
Fries
Ramona
R
Biochemistry group, Institute of Biology and Environmental Science, Faculty V, Carl von Ossietzky University Oldenburg, Oldenburg, Germany.
Reddy
Pasham Parameshwar
PP
Mikhaylova
Marina
M
Haverkamp
Silke
S
Wei
Tao
T
Müller
Michael
M
Kreutz
Michael R
MR
Koch
Karl-Wilhelm
KW
D000818:Animals; D019556:COS Cells; D002118:Calcium / Q000494:pharmacology* / Q000502:physiology; D002135:Calcium-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D002522:Chlorocebus aethiops; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D005455:Fluorescent Antibody Technique; D015151:Immunoblotting; D007150:Immunohistochemistry; D047468:Immunoprecipitation; D009226:Myristates / Q000378:metabolism*; D010870:Pineal Gland / Q000187:drug effects / Q000378:metabolism; D021381:Protein Transport / Q000187:drug effects; D051381:Rats; D011993:Recombinant Fusion Proteins; D051603:Recoverin / Q000235:genetics / Q000378:metabolism*; D012160:Retina / Q000187:drug effects / Q000378:metabolism; D020349:Surface Plasmon Resonance
D002135:Calcium-Binding Proteins; D009226:Myristates; D011993:Recombinant Fusion Proteins; D051603:Recoverin; C085577:Ca2+-binding protein-1; D002118:Calcium