Recent studies have shown that NAD(P)+ plays roles in many different cellular processes, such as protein deacetylation, protein mono- and poly-ADP-ribosylation, calcium signalling and modulation of transcription activity. Nicotinamide mononucleotide adenylyl-transferase (NMN-AT) (EC 2.7.7.1) is a central enzyme in NAD+ biosynthesis. It catalyzes the reversible reaction NMN+ ATP NAD+ + PPi . NADP+ is produced by phosphorylation of NAD+. The aim of this study was to investigate whether Saccharomyces cerevisiae mitochondria (SCM) can synthesize nicotinamide nucleotide from externally added NMN. The experimental work was articulated in the following phases: 1.In a series of preliminary experiments SCM were checked with respect to their functional features (intactness of mitochondrial outer membrane, intactness of mitochondrial inner membrane, Respiratory Control, ΔΨ generation). 2.Total NAD(P) was extracted from freshly isolated SCM and quantified by HPLC analysis. 3.SCM were incubated with NMN and ATP and the amount of NAD(P) synthesized was determined. Our findings show mitochondrial permeability to externally added NMN and a significant increase of newly synthesized NAD(P) in SCM.
Mitochondrion participates in the pathway of NAD(P) biosynthesis in Saccharomyces cerevisae
PALLOTTA, Maria Luigia;C. DI MARTINO
2007-01-01
Abstract
Recent studies have shown that NAD(P)+ plays roles in many different cellular processes, such as protein deacetylation, protein mono- and poly-ADP-ribosylation, calcium signalling and modulation of transcription activity. Nicotinamide mononucleotide adenylyl-transferase (NMN-AT) (EC 2.7.7.1) is a central enzyme in NAD+ biosynthesis. It catalyzes the reversible reaction NMN+ ATP NAD+ + PPi . NADP+ is produced by phosphorylation of NAD+. The aim of this study was to investigate whether Saccharomyces cerevisiae mitochondria (SCM) can synthesize nicotinamide nucleotide from externally added NMN. The experimental work was articulated in the following phases: 1.In a series of preliminary experiments SCM were checked with respect to their functional features (intactness of mitochondrial outer membrane, intactness of mitochondrial inner membrane, Respiratory Control, ΔΨ generation). 2.Total NAD(P) was extracted from freshly isolated SCM and quantified by HPLC analysis. 3.SCM were incubated with NMN and ATP and the amount of NAD(P) synthesized was determined. Our findings show mitochondrial permeability to externally added NMN and a significant increase of newly synthesized NAD(P) in SCM.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
