SEVENSPAN TRANSMEMBRANE MOLECULES - NOVEL RECEPTORS INVOLVED IN LEUKOCYTE ADHESION

CD97 is a member of a new subgroup of seven-span transmembrane (7-TM) molecules which belong to the secretin receptor superfamily. Different from other members of the secretin receptor family, these recently ch aracterized molecules have extended extracellular regions comprising s everal EGF domains near the NH2 terminus. We recently demonstrated tha t the extracellular part of CD97 is involved in intercellular adhesion since it specifically binds to CD55 (decay accelerating factor), a re gulatory protein of the complement cascade. To our knowledge this is t he first demonstration of a cellular ligand for a 7-TM molecule. (C) 1 996 Elsevier Science B.V.