MOLECULAR-CLONING OF F4 80, A MURINE MACROPHAGE-RESTRICTED CELL-SURFACE GLYCOPROTEIN WITH HOMOLOGY TO THE G-PROTEIN LINKED TRANSMEMBRANE-7 HORMONE-RECEPTOR FAMILY/

F4/80 is a monoclonal antibody that recognizes a murine macrophage-res tricted cell surface glycoprotein and has been extensively used to cha racterize macrophage populations in a wide range of immunological stud ies. Apart from the tightly regulated pattern of expression of the F4/ 80 antigen, little is known about its possible role in macrophage diff erentiation and function, We have sought to characterize the molecule at the molecular level, through the isolation of cDNA clones, and now describe the sequence of the F4/80 protein, The primary amino acid seq uence demonstrates homology to two protein superfamilies. The NH2-term inal region consists of seven epidermal growth factor-like domains, se parated by approximately 300 amino acids from a COOH-terminal region t hat shows homology to members of the seven transmembrane-spanning fami ly of hormone receptors, The potential role of these distinct domains is discussed with respect to the possible function of the F4/80 molecu le.