HEPARIN-BINDING EGF-LIKE GROWTH-FACTOR

HB-EGF is a heparin-binding member of the EGF family that was initiall y identified in the conditioned medium of human macrophages. Soluble m ature HB-EGF is proteolytically processed from a larger membrane-ancho red precursor and is a potent mitogen and chemotactic factor for fibro blasts, smooth muscle cells but not endothelial cells. HB-EGF activate s two EGF receptor subtypes, HER1 and HER4 and binds to cell surface H SPG. The transmembrane form of HB-EGF is a juxtacrine growth and adhes ion factor and is uniquely the receptor for diphtheria toxin. HB-EGF g ene expression is highly regulated, for example by cytokines, growth f actors, and transcription factors such as MyoD. HB-EGF has been implic ated as a participant in a variety of normal physiological processes s uch as blastocyst implantation and wound healing, and in pathological processes such as tumor growth, SMC hyperplasia and atherosclerosis. ( C) 1997 Elsevier Science B.V.