The phosphate makes a difference: cellular functions of NADP

Abstract

Recent research has unraveled a number of unexpected functions of the pyridine nucleotides. In this review, we will highlight the variety of known physiological roles of NADP. In its reduced form (NADPH), this molecule represents a universal electron donor, not only to drive biosynthetic pathways. Perhaps even more importantly, NADPH is the unique provider of reducing equivalents to maintain or regenerate the cellular detoxifying and antioxidative defense systems. The roles of NADPH in redox sensing and as substrate for NADPH oxidases to generate reactive oxygen species further extend its scope of functions. NADP(+), on the other hand, has acquired signaling functions. Its conversion to second messengers in calcium signaling may have critical impact on important cellular processes. The generation of NADP by NAD kinases is a key determinant of the cellular NADP concentration. The regulation of these enzymes may, therefore, be critical to feed the diversity of NADP-dependent processes adequately. The increasing recognition of the multiple roles of NADP has thus led to exciting new insights in this expanding field.

Nad

“…1) 92-96 have also been shown to contribute to releasing Ca 2+ ions into the cytoplasm. 45,97 When NAD(P) pools are large, the induction of PR genes is thought to be mediated by Ca 2+ signaling (Fig. 2): First, Ca 2+ trapping with the chelation agent EGTA inhibits PR genes expression upon treatment with exogenous NAD(P).…”

Proteomic and transcriptomic analysis of the response to bile stress of Lactobacillus casei BL23

“…This is the only de novo pathway for the biosynthesis of NADP and plays a critical role in the maintenance of the NAD : NADP ratio (Shi et al, 2009). Recent research has shown that NADP(H + ) is a key provider of reducing equivalents to maintain or regenerate the cellular detoxifying and antioxidative defence systems (Agledal et al, 2010). Therefore, the increase in NAD kinase expression may relate to oxidative stress caused by bile (Begley et al, 2005).…”

Thermococcus kodakarensis : the key to affordable biohydrogen production

“…However, it was not until 2000 that the gene encoding NADK was identified by Kawai et al in Micrococcus flavus and Mycobacterium tuberculosis H37Rv [167]. Since then, NADKs from various organisms have been studied in detail, and although the exact physiological functions, related pathways, and regulatory mechanisms have not always clearly been elucidated, some reviews of NADK structure, function, and potential applications are available [142,152,155,175,458].…”

“…The consumption of NADP + is thus connected to the consumption of NAD + and to the regulation of various major biological activities such as DNA repair, gene expression, apoptosis, nitrogen fixation, and calcium homeostasis [142,148,152,155,156]. [148,155,160,161].…”

“…Hence, many papers about its structure, function, and application are available, including reviews by Kawai and Murata [152], Shi et al [175], and Agledal et al [142]. [52,[177][178][179] and reach 1820 for mammalian cells [180], whereas NADP + /NADPH values range from 0.017 to 0.95 [52,[177][178][179].…”