Calcium-dependent phospholipid-binding protein that plays a role in calcium-mediated intracellular processes. Binds phospholipid membranes in a calcium-dependent manner. Plays a role in dendrite formation by melanocytes. Interacts (via second C2 domain) with OS9 (via C-terminus); this interaction occurs in a calcium-dependent manner in vitro. May interact with NECAB1. Mainly cytoplasmic in absence of calcium. Associated predominantly with membranes in presence of calcium. Translocates to the cell membrane in a calcium-dependent manner. Colocalized with transferrin in intracellular clathrin-coated membrane vesicles in a calcium-dependent manner. The C2 domain 1 binds phospholipids in a calcium-independent manner and is not necessary for calcium-mediated translocation and association to the plasma membrane. The C2 domain 2 binds phospholipids in a calcium-dependent manner and is necessary for calcium-mediated translocation and association to the plasma membrane. The linker region contributes to the calcium-dependent translocation and association to the plasma membrane. The VWFA domain is necessary for association with intracellular clathrin-coated vesicles in a calcium-dependent manner. Belongs to the copine family.