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.
Biochemistry group, Institute of Biology and Environmental Science, Faculty V, Carl von Ossietzky University Oldenburg, Oldenburg, Germany.
Ramona
R
Fries
Pasham Parameshwar
PP
Reddy
Marina
M
Mikhaylova
Silke
S
Haverkamp
Tao
T
Wei
Michael
M
Müller
Michael R
MR
Kreutz
Karl-Wilhelm
KW
Koch
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