title: Rapid interferon-gamma-stimulated tyrosine phosphorylation of cytosolic and membranal proteins in HL-60 promyelocytic cells.
abstract: The involvement of tyrosine phosphorylation in the early stages of interferon-gamma (IFN gamma)-induced monocytic differentiation of HL-60 cells was studied. Immunoblotting analysis demonstrated that IFN gamma induced rapid changes in the tyrosine phosphorylation of several endogenous cytosolic and membranal proteins. The most prominent of these polypeptides was a 84 kDa protein. In membranes, the IFN gamma-induced phosphorylation of this protein was detectable in 5 min, remained elevated for 3 h and declined thereafter, while a gradual decrease in the phosphotyrosine content was observed in cytosols. In parallel, a 40% increase in the phosphotyrosine phosphatase activity was detected in the later stages of IFN gamma treatment. Rapid changes in tyrosine phosphorylation were detected also in a 64 kDa protein. In contrast, 2-day exposure to IFN gamma was needed to potentiate significantly the tyrosine phosphorylation of a 36 kDa membranal polypeptide. These data support the involvement of tyrosine phosphorylation in the early stages of IFN gamma-induced monocytic differentiation of HL-60 cells.
authors.affiliation: Ben-Gurion University of the Negev, Faculty of Health Sciences, Beer Sheva, Israel.
authors.forename: M
authors.initials: M
authors.lastname: Kafka
authors.forename: A
authors.initials: A
authors.lastname: Dvilansky
authors.forename: I
authors.initials: I
authors.lastname: Nathan
mesh_terms: D002454:Cell Differentiation; D003600:Cytosol / Q000378:metabolism; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D015473:Leukemia, Promyelocytic, Acute / Q000378:metabolism* / Q000473:pathology; D008565:Membrane Proteins / Q000378:metabolism*; D009000:Monocytes / Q000473:pathology; D009363:Neoplasm Proteins / Q000378:metabolism*; D010766:Phosphorylation; D019000:Phosphotyrosine; D017027:Protein Tyrosine Phosphatases / Q000378:metabolism; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism*
chemical_list: D008565:Membrane Proteins; D009363:Neoplasm Proteins; D019000:Phosphotyrosine; D014443:Tyrosine; D007371:Interferon-gamma; D017027:Protein Tyrosine Phosphatases