title: NAD-dependent inhibition of the NAD-glycohydrolase activity in A549 cells.
abstract: NAD glycohydrolases are enzymes that catalyze the hydrolysis of NAD to produce ADP-ribose and nicotinamide. Regulation of these enzymes has not been fully elucidated. We have identified a NAD-glycohydrolase activity associated with the outer surface of the plasma membrane in human lung epithelial cell line A549. This activity is negatively regulated by its substrate beta-NAD but not by alpha-NAD. Partial restoration of NADase activity after incubation of the cells with arginine or histidine, known ADP-ribose acceptors, suggests that inhibition be regulated by ADP-ribosylation. A549 do not undergo to apoptosis upon NAD treatment indicating that this effect be likely mediated by a cellular component(s) lacking in epithelial cells.
authors.affiliation: Dipartimento di Scienze Morfologiche e Biochimiche Comparate, Universita' degli Studi di Camerino, Italy. enrico-balducci@durou.it
authors.forename: Enrico
authors.initials: E
authors.lastname: Balducci
authors.forename: Luigi G
authors.initials: LG
authors.lastname: Micossi
mesh_terms: D036541:ADP-ribosyl Cyclase / Q000378:metabolism; D017209:Apoptosis; D001120:Arginine / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism*; D004847:Epithelial Cells / Q000201:enzymology*; D005434:Flow Cytometry; D006639:Histidine / Q000378:metabolism; D006801:Humans; D006868:Hydrolysis; D008168:Lung / Q000166:cytology*; D009243:NAD / Q000494:pharmacology*; D009244:NAD+ Nucleosidase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D011419:Propidium / Q000378:metabolism; D021381:Protein Transport
chemical_list: D009243:NAD; D011419:Propidium; D006639:Histidine; D001120:Arginine; D036541:ADP-ribosyl Cyclase; D009244:NAD+ Nucleosidase