title: The GTP-binding regulatory proteins of neuroblastoma x glioma, NG108-15, and glioma, C6, cells. Immunochemical evidence of a pertussis toxin substrate that is neither Ni nor No.
abstract: Amounts of the guanine nucleotide binding regulatory proteins which are also pertussis toxin substrates (such as Ni and No) were measured in rat glioma, C6BU-1, cells and in neuroblastoma X glioma, NG108-15, hybrid cells. Measurements were performed both by quantitating pertussis toxin catalyzed ADP-ribosylation and by quantitative immunoblotting with affinity purified antibodies specific for Ni or No. The amounts of pertussis toxin substrate in C6 and NG108-15 cells are 7.5 and 0.6 pmol/mg membrane protein, respectively. These levels are minimum values and higher estimates of the total amounts of N proteins in the two cells are obtained by quantitative immunoblot analysis of the beta-subunit common to all N proteins. Immunoblots with specific antibodies show that NG108-15 cells contain 3.8 pmol/mg of No and detectable but small (less than 0.1 pmol/mg) amounts of Ni. In contrast, C6 cell membranes contain no detectable No and only 0.14 pmol/mg Ni. Thus, C6 cells contain large amounts of a pertussis toxin substrate which is neither Ni nor No.
authors.forename: G
authors.initials: G
authors.lastname: Milligan
authors.forename: P
authors.initials: P
authors.lastname: Gierschik
authors.forename: A M
authors.initials: AM
authors.lastname: Spiegel
authors.forename: W A
authors.initials: WA
authors.lastname: Klee
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000201:enzymology; D019204:GTP-Binding Proteins / Q000276:immunology* / Q000378:metabolism; D005910:Glioma / Q000201:enzymology; D006822:Hybrid Cells / Q000201:enzymology; D007163:Immunosorbent Techniques; D046911:Macromolecular Substances; D009447:Neuroblastoma / Q000201:enzymology; D037342:Pertussis Toxin; D051381:Rats; D010566:Virulence Factors, Bordetella / Q000378:metabolism*
chemical_list: D046911:Macromolecular Substances; D010566:Virulence Factors, Bordetella; D037342:Pertussis Toxin; D019204:GTP-Binding Proteins