YCL047C/POF1 is a novel nicotinamide mononucleotide adenylyltransferase (NMNAT) in Saccharomyces cerevisiae.
NAD(+) is an essential metabolic cofactor involved in various cellular biochemical processes. Nicotinamide riboside (NR) is an endogenously produced key pyridine metabolite that plays important roles in the maintenance of NAD(+) pool. Using a NR-specific cell-based screen, we identified mutants that exhibit altered NR release phenotype. Yeast cells lacking the ORF YCL047C/POF1 release considerably more NR compared with wild type, suggesting that POF1 plays an important role in NR/NAD(+) metabolism. The amino acid sequence of Pof1 indicates that it is a putative nicotinamide mononucleotide adenylyltransferase (NMNAT). Unlike other yeast NMNATs, Pof1 exhibits NMN-specific adenylyltransferase activity. Deletion of POF1 significantly lowers NAD(+) levels and decreases the efficiency of NR utilization, resistance to oxidative stress, and NR-induced life span extension. We also show that NR is constantly produced by multiple nucleotidases and that the intracellular NR pools are likely to be compartmentalized, which contributes to the regulation of NAD(+) homeostasis. Our findings may contribute to the understanding of the molecular basis and regulation of NAD(+) metabolism in higher eukaryotes.
From the Department of Microbiology and Molecular Genetics, College of Biological Sciences, University of California, Davis, California 95616.
Michiko
M
Kato
From the Department of Microbiology and Molecular Genetics, College of Biological Sciences, University of California, Davis, California 95616 slin@ucdavis.edu.
Su-Ju
SJ
Lin
D000595:Amino Acid Sequence; D006706:Homeostasis / Q000502:physiology; D008969:Molecular Sequence Data; D009243:NAD / Q000096:biosynthesis*; D009536:Niacinamide / Q000031:analogs & derivatives / Q000378:metabolism; D009612:Nicotinamide-Nucleotide Adenylyltransferase / Q000235:genetics / Q000378:metabolism*; D011726:Pyridinium Compounds; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*
D011726:Pyridinium Compounds; D029701:Saccharomyces cerevisiae Proteins; C018613:nicotinamide-beta-riboside; D009243:NAD; D009536:Niacinamide; D009612:Nicotinamide-Nucleotide Adenylyltransferase; C000592233:POF1 protein, S cerevisiae
Cell Metabolism; Metabolic Regulation; NAD Biosynthesis; Nicotinamide Mononucleotide Adenylyltransferase; Nicotinamide Riboside Salvage; Yeast Genetics; Yeast Metabolism