NCIt definition : A family of glycosyltransferases that catalyzes both the transfer of an adenosine
diphosphate (ADP)-ribosyl group of oxidized nicotinamide adenine dinucleotide (NAD(
)) to an acceptor carboxyl group in protein substrates and continued transfer of ADP-ribosyl
groups to the 2'-position of the terminal adenosine moiety, building up a polymer
with an average chain length of 20-30 units. This process (poly-ADP-ribosylation)
is involved in a number of cellular processes, including DNA repair, genomic stability
and the regulation of programmed cell death.;