Calcium binding proteins (CaBP) play a crucial role in the calcium-mediated cellular signal transduction pathway in the central nervous system. The CaBP family shares much similarity with CaM I (calmodulin), and it has been shown that CaBP proteins can substitute functionally for, and possibly augment the function of, CaM I. CaBP7 (Calcium-binding protein 7), contains two EF-hand domains for calcium binding and shares 70% homology with CaBP8 and 50% homology with CaM I. It negatively regulates Golgi-to-plasma membrane trafficking by interacting with PI4KB and inhibiting its activity. CaBP7 and 8 possess a targeting mechanism that is unique amongst the CaBPs that may contribute to differential functional Ca2+-sensing by these family members.