Mouse Rt6.1 is a thiol-dependent arginine-specific ADP-ribosyltransferase.

摘要: Mouse T-cell antigens Rt6.1 and Rt6.2 are glycosylphosphatidylinositol-anchored arginine-specific adenosine diphosphate (ADP)-ribosyltransferases. In the present study, we obtained evidence that an ADP-ribosyltransferase activity liberated from BALB/c mouse splenocytes by phosphatidylinositol-specific phospholipase C increased fivefold in presence of dithiothreitol was immunoprecipitated polyclonal antibodies generated against recombinant rat RT6.1. When expressed as a protein, transferase stimulated dithiothreitol, inhibited N-ethylmaleimide, while activities Glu-207 mutant RT6.1 [Hara, N., Tsuchiya, M., Shimoyama, M. (1996) J. Biol. Chem.271, 29552–29555] were unaffected either agent. addition to four cysteine residues conserved among Rt6 RT6 antigens, has two extra at positions 80 201. To investigate contribution these cysteines thiol dependency activity, Cys-80 Cys-201 replaced with serine phenylalanine, respectively, corresponding Transferase Phe-201 lost Ser-80 remained thiol-dependent. Thus, conclude is thiol-dependent ADP-ribosyltransferase, confers on transferase. Our study indicates detected attributed differs enzymatic property perhaps immunoregulatory functions.