Calcium/calmodulin-dependent protein kinase IV (CaMKIV) enhances osteoclast differentiation via the up-regulation of Notch1 protein stability

► CaMKIV and Notch1 are required for RANKL-induced osteoclast differentiation. ► Notch1-IC interacts directly with CaMKIV in intact cells. ► CaMKIV up-regulates the Notch1-IC protein stability. ► CaMKIV positively regulates Notch1 signaling through an E3 ligase, Fbw7 ► CaMKIV-mediated phosphorylation of Notch1-IC inhibits the degradation of Notch1-IC.