PROSITE documentation PDOC00344

Neuromodulin (GAP-43) signatures

Neuromodulin (also known as GAP-43, pp46, B-50, F1, and P-57) [1] is an axonal membrane protein associated with nerve growth. It is a major component of the motile growth cones that form the tips of elongating axons. Neuromodulin is an hydrophilic protein of 210 to 240 amino acid residues, which binds calmodulin and inhibits phosphatidylinositol phosphate kinase (PIP kinase). It is phosphorylated by protein kinase C, and regulates the binding of GTP to G(0) [2]. Neuromodulin contains an IQ motif (see <PDOC50096>).

Two functionally important regions of GAP-43 have been characterized: the N-terminal extremity of the protein contains two cysteine residues which are palmitoylated and are responsible for the attachment of the protein to the membrane; about forty residues downstream is a serine residue which can be phosphorylated by protein kinase C [3] and which is adjacent to the calmodulin-binding domain. We have selected those two regions as signature patterns.