title: Identification of a soluble GM-CSF binding protein in the supernatant of a human choriocarcinoma cell line.
abstract: We identified two forms of the receptor for granulocyte-macrophage colony-stimulating factor (GM-CSF) made by the human choriocarcinoma cell line JEG-3 using an affinity-labeling technique. The protein was identified in the detergent-extract was 78 kDa, very similar to that of the membrane-bound GM-CSF receptor alpha chain expressed in a wide variety of hematopoietic and nonhematopoietic cells, including JEG-3. In contrast, a 62-kDa GM-CSF binding protein, or the soluble GM-CSF receptor, was identified in the supernatant of JEG-3 cells. Utilizing the same affinity labeling technique, we did not detect the soluble GM-CSF binding protein in the supernatant of several hematopoietic cell lines, such as U-937 and KG-1, which express membrane bound alpha chain as well as beta chain. The 62-kDa soluble GM-CSF receptor is produced in abundant amounts by JEG-3, but in very small amounts, if any, by hematopoietic cell lines.
authors.affiliation: Third Department of Internal Medicine, Faculty of Medicine, University of Tokyo, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Sasaki
authors.forename: S
authors.initials: S
authors.lastname: Chiba
authors.forename: H
authors.initials: H
authors.lastname: Mano
authors.forename: Y
authors.initials: Y
authors.lastname: Yazaki
authors.forename: H
authors.initials: H
authors.lastname: Hirai
mesh_terms: D002822:Choriocarcinoma / Q000737:chemistry*; D005260:Female; D014644:Genetic Variation; D006801:Humans; D008566:Membranes / Q000737:chemistry; D016187:Receptors, Granulocyte-Macrophage Colony-Stimulating Factor / Q000032:analysis*; D012995:Solubility; D014407:Tumor Cells, Cultured; D014594:Uterine Neoplasms / Q000737:chemistry*
chemical_list: D016187:Receptors, Granulocyte-Macrophage Colony-Stimulating Factor