title: Characterization of the cell surface receptor for granulocyte-macrophage colony-stimulating factor.
abstract: 125I-labeled recombinant murine granulocyte-macrophage colony-stimulating factor (GM-CSF) was used to characterize receptors specific for this lymphokine on the surface of cells of both myelomonocytic and T-cell origin. GM-CSF binding to these cells was specific and saturable. Equilibrium binding studies revealed that on all cell types examined, GM-CSF bound to a single class of high affinity receptor (1000-5000 receptors/cell) with a Ka of 10(8)-10(9) M-1. More extensive characterization with P388D1 cells showed that binding of GM-CSF was rapid at 37 degrees C with a slow subsequent dissociation rate. Among a panel of lymphokines and growth hormones, only unlabeled natural or recombinant GM-CSF were able to compete for the binding of 125I-GM-CSF to these cells. Affinity cross-linking experiments with the homobifunctional cross-linking reagents disuccinimidyl suberate, disuccinimidyl tartrate, and dithiobis(succinimidyl propionate) resulted in the identification of a receptor protein with a Mr of 130,000 on five out of the seven cell types examined. This protein was extremely sensitive to proteolysis and in the absence of protease inhibitors was degraded to a form with an approximate Mr of 70,000. A receptor protein of Mr 180,000, in addition to the Mr 70,000 protein, was found on bone marrow cells and on P815 cells. The potential tissue-specific molecular heterogeneity associated with the GM-CSF receptor may help to explain some of the diverse biological effects associated with this growth and differentiation factor.
mesh_terms: D000818:Animals; D002460:Cell Line; D003115:Colony-Stimulating Factors / Q000378:metabolism*; D003432:Cross-Linking Reagents / Q000494:pharmacology; D006098:Granulocytes / Q000378:metabolism; D007700:Kinetics; D007941:Leukemia P388 / Q000378:metabolism; D008264:Macrophages / Q000378:metabolism; D051379:Mice; D008970:Molecular Weight; D011956:Receptors, Cell Surface / Q000378:metabolism*; D016184:Receptors, Colony-Stimulating Factor; D013388:Succinimides / Q000494:pharmacology
chemical_list: D003115:Colony-Stimulating Factors; D003432:Cross-Linking Reagents; D011956:Receptors, Cell Surface; D016184:Receptors, Colony-Stimulating Factor; D013388:Succinimides; C019358:disuccinimidyl suberate