Synthesizing and salvaging NAD: lessons learned from Chlamydomonas reinhardtii.

ABSTRACT: The essential coenzyme nicotinamide adenine dinucleotide (NAD+) plays important roles in metabolic reactions and cell regulation in all organisms. Bacteria, fungi, plants, and animals use different pathways to synthesize NAD+. Our molecular and genetic data demonstrate that in the unicellular green alga Chlamydomonas NAD+ is synthesized from aspartate (de novo synthesis), as in plants, or nicotinamide, as in mammals (salvage synthesis). The de novo pathway requires five different enzymes: L-aspartate oxidase (ASO), quinolinate synthetase (QS), quinolate phosphoribosyltransferase (QPT), nicotinate/nicotinamide mononucleotide adenylyltransferase (NMNAT), and NAD+ synthetase (NS). Sequence similarity searches, gene isolation and sequencing of mutant loci indicate that mutations in each enzyme

SUBMITTER: Lin H 

PROVIDER: S-EPMC2936527 | biostudies-literature | 2010 Sep

REPOSITORIES: biostudies-literature