Mono-ADP-ribosylation is one of the posttranslational protein modifications regulating cellular metabolism (e.g. nitrogen fixation) in prokaryotes. Mono-ADP-ribosylation is a process in which the ADP-ribose moiety of nicotinamide adenine dinucleotide is transferred to an acceptor amino acid. Five mammalian ADP-ribosyltransferases (ART1-ART5) have been cloned, and each ART is expressed in different tissues. ART5 (ADP-ribosyltransferase 5), also known as Ecto-ADP-ribosyltransferase 5, is a 292 amino acid secretory protein that is expressed in testis, heart, skeletal muscle and lymphoma. Functionally, ART5 is implicatetd to play a role in cell signaling and metabolism cascades. Two isoforms of ART5 exist as a result of alternative splicing events.
