Identification and characterization of an intracellular protein complex that binds fibroblast growth factor-2 in bovine brain.

The fibroblast growth factor (FGF) family is composed of polypeptides with sequence identity which signal through transmembrane tyrosine kinase receptors. We report here the purification from bovine brain microsomes of an FGF-2-binding complex composed of three proteins of apparent molecular masses 150 kDa, 79 kDa and 46 kDa. Only the 150 kDa and 79 kDa proteins bound FGF-2 in cross-linking and ligand-blotting experiments.