ADP Ribosylhydrolase Like Protein 2 (ADPRHL2)

ADP-ribosylation is a reversible posttranslational modification used to regulate protein function. ADP-ribosyltransferases transfer ADP-ribose from NAD+ to the target protein, and ADP-ribosylhydrolases, such as ADPRHL2, reverse the reaction.The deduced human protein contains 363 amino acids and is 92% identical to its mouse homolog. Northern blot analysis of mouse tissues showed ubiquitous expression of Arh3. Western blot analysis of a human liver carcinoma cell line detected ARH3 in the cytosolic fraction, but not in nuclei. Analysis of mouse brain and liver revealed Arh3 in both the cytosolic and nuclear fractions.ARH3 activity was enhanced by MgCl(2+). Mutation of asp77 and asp78 of ARH3 eliminated ribosylhydrolase activity, but not binding to ADP ribose.