ADP-ribosylation of tuftsin suppresses its receptor-binding capacity and phagocytosis-stimulating activity to murine peritoneal macrophages.
Arginine-specific ADP-ribosyltransferase present in granules of chicken polymorphonuclear leukocytes (so-called heterophils) is released into the extracellular space by stimulus of calcium ionophore A23187 or opsonized zymosan [Terashima et al. (1996) J. Biochem. 120, 1209-1215]. In the present work, we examined extracellular targets of the released transferase and identified tuftsin, a phagocytosis-stimulating tetrapeptide derived from leukokinin, as a preferential substrate of the enzyme in chicken plasma. Specific binding of FITC-tuftsin to murine peritoneal macrophages, observed under a fluorescent microscope, was impaired by ADP-ribosylation of the labelled peptide. Phagocytic assay analyzed by flow cytometry revealed that ADP-ribosylation of tuftsin decreased its phagocytosis-stimulating activity towards the macrophages. Thus, the ADP-ribosylation of tuftsin apparently decreases its biological activity and ADP-ribosylation may possibly be involved in inflammatory processes through alterations in tuftsin activity.
Terashima
M
M
Department of Biochemistry, Shimane Medical University, Izumo, Japan.
Hara
N
N
Badruzzaman
M
M
Shimoyama
M
M
Tsuchiya
M
M
D000246:Adenosine Diphosphate Ribose / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology; D002645:Chickens; D002851:Chromatography, High Pressure Liquid; D005434:Flow Cytometry; D016650:Fluorescein-5-isothiocyanate; D005456:Fluorescent Dyes; D017737:Macrophages, Peritoneal / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D009243:NAD / Q000378:metabolism; D009895:Opsonin Proteins; D010587:Phagocytosis; D011971:Receptors, Immunologic / Q000378:metabolism*; D014405:Tuftsin / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology*; D015054:Zymosan / Q000494:pharmacology
D005456:Fluorescent Dyes; D009895:Opsonin Proteins; D011971:Receptors, Immunologic; C029695:tuftsin receptor; D009243:NAD; D000246:Adenosine Diphosphate Ribose; D000001:Calcimycin; D015054:Zymosan; D016650:Fluorescein-5-isothiocyanate; D014405:Tuftsin; D002118:Calcium