guanosine-5--o-(3-thiotriphosphate) and Lupus-Erythematosus--Systemic

We describe here a novel 26-kDa posphoprotein (p26), associated to the T cell receptor of CD4-CD8- lymph node cells of lpr/lpr mice, but not present in significant amounts in control mouse cells including polyclonally activated T cells. lpr p26 is constitutively phosphorylated on a tyrosyl residue. It is most likely a member of the G protein family and displays high GTP-binding and GTPase activities both unsensitive to interleukin 2. Bordetella pertussis toxin has no effect on the spontaneously enhanced GTP hydrolysis. The traits associated to p26 could contribute to the distinctive features of lpr/lpr double-negative cells.

Topics: Animals; Antigens, Differentiation, T-Lymphocyte; CD3 Complex; Cell Membrane; Cholera Toxin; GTP-Binding Proteins; Guanosine 5'-O-(3-Thiotriphosphate); Interleukin-2; Lupus Erythematosus, Systemic; Lymph Nodes; Mice; Mice, Mutant Strains; Molecular Weight; Peptide Mapping; Pertussis Toxin; Phosphoproteins; Receptors, Antigen, T-Cell; Signal Transduction; T-Lymphocyte Subsets; Virulence Factors, Bordetella