Co-immunoprecipitation was performed as previously described 35 (link). HEK 293 cells were grown in DMEM media supplemented with 10% FBS to 60% confluence in 6-well plates, and transfected pCAG-CaM or pCAG-CaM(1,2,3,4), pCAG-myc-TCF4, and pCAG-eGFP using the Lipofectamine 3000 reagent. After 48 hours, cells were washed, harvested in NP40 lysis buffer (50mM Tris-HCl pH 7.4, 137mM NaCl, 1% NP40) supplemented with Halt Protease/Phosphatase inhibitor cocktail, measure by Pierce BCA kit, and boiled in LDS/PAGE sample buffer. Protein A Dynabeads (Life Technologies) were prepared with anti-myc (AbCam, catalog number: ab9106) antibody per the manufacturers instructions. The bead-antibody complex was incubated with transfected cellular lysates overnight at 4°C on a rotating wheel. Washing and elution steps were followed per the manufacturer’s instructions. Immunoprecipitated protein (50μg) or input control protein lysates (50 μg) were resolved with Novex 4–12% gradient SDS/PAGE gel and then transferred onto a nitrocellulose membrane (Life Technologies), probed with appropriate antibodies (1:1000 anti-myc (Abcam), 1:1000 anti-Calmodulin (Millipore, catalog number: 05-173)) and analyzed using 1:20000 LI-COR IR dye conjugated secondary antibodies.