Purification and properties of cytosolic and mitochondrial malic enzyme isolated from human brain

Bukato, Grzegorz; Kochan, Zdzisław; Świerczyński, Julian

doi:10.1016/1357-2725(94)00057-3

Cited by 24 publications

(33 citation statements)

References 25 publications

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“…In mammalian cells, the pentose phosphate pathway, particularly the rate-limiting enzyme glucose-6-phosphate dehydrogenase (G6PD) located in the cytosol, has been regarded as a critical source of NADPH generation from NADP + (Pandolfi et al, 1995; Juhnke et al, 1996; Slekar et al, 1996). Other NADP + reducing enzymes include NADP-specific forms of IDP (isocitrate dehydrogenase), ME (malic enzyme), ALDH (aldehyde dehydrogenase) (Veech et al, 1969; Frenkel, 1971; Bukato et al, 1995; Jo et al, 2001; Koh et al, 2004; Kim et al, 2005). …”

Section: Discussionmentioning

confidence: 99%

MNADK, a novel liver-enriched mitochondrion-localized NAD kinase

Zhang

2013

Biology Open

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SummaryNADP+ and its reducing equivalent NADPH are essential for counteracting oxidative damage. Mitochondria are the major source of oxidative stress, since the majority of superoxide is generated from the mitochondrial respiratory chain. Because NADP+ cannot pass through the mitochondrial membrane, NADP+ generation within mitochondria is critical. However, only a single human NAD kinase (NADK) has been identified, and it is localized to the cytosol. Therefore, sources of mitochondrial NADP+ and mechanisms for maintaining its redox balance remain largely unknown. Here, we show that the uncharacterized human gene C5ORF33, named MNADK (mouse homologue 1110020G09Rik), encodes a novel mitochondrion-localized NAD kinase. In mice MNADK is mostly expressed in the liver, and also abundant in brown fat, heart, muscle and kidney, all being mitochondrion-rich. Indeed, MNADK is localized to mitochondria in Hep G2 cells, a human liver cell line, as demonstrated by fluorescence imaging. Having a conserved NAD kinase domain, a recombinant MNADK showed NAD kinase activity, confirmed by mass spectrometry analysis. Consistent with a role of NADP+ as a coenzyme in anabolic reactions, such as lipid synthesis, MNADK is nutritionally regulated in mice. Fasting increased MNADK levels in liver and fat, and obesity dramatically reduced its level in fat. MNADK expression was suppressed in human liver tumors. Identification of MNADK immediately suggests a model in which NADK and MNADK are responsible for de novo synthesis of NADP+ in cytosol and mitochondria, respectively, and therefore provides novel insights into understanding the sources and mechanisms of mitochondrial NADP+ and NADH production in human cells.

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Section: Discussionmentioning

confidence: 99%

MNADK, a novel liver-enriched mitochondrion-localized NAD kinase

Zhang

2013

Biology Open

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“…The reaction helps to transfer cytoplasmic oxaloacetate to the mitochondrion which is important in the tricarboxylic acid (TCA) cycle for the formation of citrate with acetyl-CoA for generating malate which can feed the cytosolic gluconeogenic pathway (Bukato et al, 1995;Singh et al, 2001). Means with different superscripts (column) are significantly different (p50.05).…”

Section: Discussionmentioning

confidence: 99%

Effect of cocoyam (Colocasia esculenta), unripe plantain (Musa paradisiaca) or their combination on glycated hemoglobin, lipogenic enzymes, and lipid metabolism of streptozotocin-induced diabetic rats

Eleazu

Iroaganachi

2015

Pharmaceutical Biology

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“…The structure of plant and animal NADP-MEs is predominantly tetrameric, with relative molecular mass of one subunit ranging from 62,000 to 67,000 [12,15,16]. NADP-malic enzymes in plants are encoded by a small gene family.…”

Section: Introductionmentioning

confidence: 99%

Effect of Potato Virus Y on the NADP-Malic Enzyme from Nicotiana tabacum L.: mRNA, Expressed Protein and Activity

Doubnerová

Müller

Čeřovská

et al. 2009

IJMS

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The effect of biotic stress induced by viral infection (Potato virus Y, strain NTN and O) on NADP-malic enzyme (EC 1.1.1.40) in tobacco plants (Nicotiana tabacum L., cv. Petit Havana, SR1) was tested at the transcriptional, translational and activity level. The increase of enzyme activity in infected leaves was correlated with the increased amount of expressed protein and with mRNA of cytosolic NADP-ME isoform. Transcription of the chloroplastic enzyme was not influenced by viral infection. The increase of the enzyme activity was also detected in stems and roots of infected plants. The effect of viral infection induced by Potato virus Y, NTN strain, causing more severe symptoms, was compared with the effect induced by milder strain PVYO. The observed increase in NADP-malic enzyme activity in all parts of the studied plants was higher in the case of PVYNTN strain than in the case of strain PVYO. The relevance of NADP-malic enzyme in plants under stress conditions was discussed.

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Purification and properties of cytosolic and mitochondrial malic enzyme isolated from human brain

Cited by 24 publications

References 25 publications

MNADK, a novel liver-enriched mitochondrion-localized NAD kinase

MNADK, a novel liver-enriched mitochondrion-localized NAD kinase

Effect of cocoyam (Colocasia esculenta), unripe plantain (Musa paradisiaca) or their combination on glycated hemoglobin, lipogenic enzymes, and lipid metabolism of streptozotocin-induced diabetic rats

Effect of Potato Virus Y on the NADP-Malic Enzyme from Nicotiana tabacum L.: mRNA, Expressed Protein and Activity

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