Fig. 4.

CaMKII-mediated phosphorylation enhances CaM binding to CT1. a Pull-down assay for CaM binding to GST-fusion CT1, CT2 and CT3 at 1 mM [Ca²⁺]. Lane 1 calibrating CaM (5 μg), lane 2 GST alone (negative control), lane 3 GST-CT1, lane 4 GST-CT2, lane 5 GST-CT3. b Pull-down assay for CaM binding to CT1 after various treatments at 1 mM [Ca²⁺]. Lane 1 non-treated, lane 2 calf intestinal alkaline phosphatase 1 (CIP), lane 3 CaMKIIT286D + ATP; or lane 4 first with CIP then with CaMKIIT286D + ATP. c Concentration-dependent binding of CaM to GST-CT1 treated with CaMKII (squares), none (control, circles) and CIP (triangles). Data were from three independent experiments