Mammalian NADH diphosphatases of the Nudix family: cloning and characterization of the human peroxisomal NUDT12 protein.

.Expression of NUDT12 as a C-terminal fusion to greenfluorescent protein revealed that it was targeted to peroxisomesby the C-terminal tripeptide PNL acting as a novel type 1 peroxi-somaltargetingsignal.DeletionofPNLresultedindiffusecellularfluorescence. In addition, C-terminal, but not N-terminal, fusionswithorwithoutthePNLsignalaccumulatedinlarge,unidentifiedcytoplasmic structures. NUDT12 may act to regulate the con-centration of peroxisomal nicotinamide nucleotide cofactors re-quired for oxidative metabolism in this organelle.Key words: baculovirus, nucleotide metabolism, Nudix hydro-lase, pyrophosphatase.