Versatile physiological functions of the Nudix hydrolase family in Arabidopsis

Nudix hydrolases are widely distributed in all kingdoms of life and have the potential to hydrolyze a wide range of organic pyrophosphates, including nucleoside di- and triphosphates, nucleotide coenzymes, nucleotide sugars, and RNA caps. However, except for E. coli MutT and its orthologs in other organisms that sanitize oxidized nucleotides to prevent DNA and RNA mutations, the functions of Nudix hydrolases had largely remained unclear until recently, because many members of this enzyme family exhibited broad substrate specificities. There is now increasing evidence to show that their functions extend into many aspects of the regulation of cellular responses. This review summarizes current knowledge on the molecular and enzymatic properties as well as physiological functions of Arabidopsis Nudix hydrolases. The information presented here may provide novel insights into the physiological roles of these enzymes in not only plant species, but also other organisms.