title: The influence of tissue transglutaminase on the function of Fc receptors.
abstract: In contrast to FcRII the soluble Fc receptor (FcRI) of human peripheral mononuclear blood cells (PMBC) is shed from PMBC following a 4-37 degrees C temperature shift and inhibits rosette formation of nonshed PMBC with antibody-coated erythrocytes (EA). Purified FcR, could be polymerized by tissue transglutaminase as was revealed by SDS-polyacrylamide gel electrophoresis. Comparing the Sephadex G-150 elution profile of the EA rosette inhibitory capacity of FcRI vs FcRI incubated in the presence of transglutaminase, the latter was found in a higher mol. wt region and could inhibit rosette formation by both FcRI and FcRII. Furthermore, the shedding of FcRI could be prevented by the addition of transglutaminase or Ca2+-ionophore A23187 (which leads to the activation of PMBC transglutaminase) to the cell suspension. The function of FcRII was not affected by either the addition of transglutaminase or Ca2+-ionophore to the cells. The results point to the involvement of transglutaminase in the determination of the functional state of the Fc receptor on the cell surface.
mesh_terms: D002462:Cell Membrane / Q000502:physiology; D006801:Humans; D008214:Lymphocytes / Q000502:physiology*; D008565:Membrane Proteins / Q000378:metabolism; D011961:Receptors, Fc / Q000502:physiology*; D012397:Rosette Formation; D013696:Temperature; D005723:gamma-Glutamyltransferase / Q000502:physiology*
chemical_list: D008565:Membrane Proteins; D011961:Receptors, Fc; D005723:gamma-Glutamyltransferase