GAP-43 Proteins and Enzymes

GAP-43 is a neuron growth cone-associated member of the neuromodulin family. GAP-43 contains an N-terminal lipid binding motif, a calmodulin-binding IQ domain and a C-terminus with four potential serine phosphorylation sites, one of which inhibits the calmodulin binding. Unphosphorylated calmodulin-bound GAP-43 is always associated with neurite retraction, while phosphorylated GAP-43 stabilizes actin filaments and promotes growth cone extension.