NAD+ metabolism (Homo sapiens)
From WikiPathways
Description
NAD+ metabolism in different cellular compartments. The different precursors to intracellular NAD metabolism - tryptophan, nicotinic acid (NA), nicotinamide, NR, and NMN - are shown, along with their extra-cellular metabolism by CD38 and CD73. The cytoplasmic and nuclear NAD+ pools probably equilibrate by diffusion through the nuclear pore. However, the mitochondrial membrane is impermeable to both NAD+ and NADH. Reducing equivalents generated by glycolysis are transferred to the mitochondrial matrix via the malate/aspartate shuttle and the glyceraldehyde-3-phosphate shuttle. The resulting mitochondrial NADH (malate/aspartate shuttle) is oxidized by complex I in the electron transport chain, whereas the resulting FADH2 (glyceraldehyde-3-phosphate shuttle) is oxidized by complex II. In each of the three compartments, different NAD+-consuming enzymes lead to the generation of nicotinamide, which is recycled via the NAD+ salvage pathway. Different forms of the NMNAT enzyme and sirtuins are localized in different compartments. The nature of the salvage pathway for NAD+ in mitochondria has not been fully resolved, although NMNAT3 has been found in mitochondria.
Quality Tags
Ontology Terms
Bibliography
- Verdin E; ''NAD⁺ in aging, metabolism, and neurodegeneration.''; Science, 2015 PubMed Europe PMC Scholia
History
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External references
DataNodes
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Name | Type | Database reference | Comment |
---|---|---|---|
ART | GeneProduct | ||
CD38 | GeneProduct | ENSG00000004468 (Ensembl) | |
CD73 | GeneProduct | ENSG00000135318 (Ensembl) | |
FADH2 | Metabolite | HMDB0001197 (HMDB) | |
FADH | Metabolite | HMDB0001197 (HMDB) | |
Glyceraldehyde
3-phosphate shuttle | Pathway | ||
Glycolysis | Pathway | WP534 (WikiPathways) | |
L-Tryptophan | Metabolite | HMDB0000929 (HMDB) | |
Lactate | Metabolite | HMDB0000190 (HMDB) | |
Malate/aspartate shuttle | Pathway | ||
NADH | Metabolite | HMDB0001487 (HMDB) | |
NAD | Metabolite | HMDB0000902 (HMDB) | |
NADK | GeneProduct | ENSG00000008130 (Ensembl) | |
NADPH | Metabolite | HMDB0000221 (HMDB) | |
NADP | Metabolite | HMDB0000217 (HMDB) | |
NAMPT | GeneProduct | ENSG00000105835 (Ensembl) | |
NMNAT1 | GeneProduct | ENSG00000173614 (Ensembl) | |
NMNAT2 | GeneProduct | ENSG00000157064 (Ensembl) | |
NMNAT3 | GeneProduct | ENSG00000163864 (Ensembl) | |
NRK | GeneProduct | ENSG00000123572 (Ensembl) | |
Nicotinamide mononucleotide | Metabolite | 13553 (Chemspider) | |
Nicotinamide riboside | Metabolite | HMDB0000855 (HMDB) | |
Nicotinamide ribotide | Metabolite | 13553 (Chemspider) | |
Nicotinamide | Metabolite | HMDB0001406 (HMDB) | |
Nicotinamide | Metabolite | HMDB0001488 (HMDB) | |
Nicotinic acid mononucleotide | Metabolite | HMDB0001132 (HMDB) | |
Nicotinic acid | Metabolite | HMDB0001488 (HMDB) | |
PARP1 | GeneProduct | ENSG00000143799 (Ensembl) | |
PRPP | Metabolite | HMDB0000280 (HMDB) | |
Pyruvate | Metabolite | HMDB0000243 (HMDB) | |
SIRT1 | GeneProduct | ENSG00000096717 (Ensembl) | |
SIRT2 | GeneProduct | ENSG00000068903 (Ensembl) | |
SIRT3 | GeneProduct | ENSG00000142082 (Ensembl) | |
SIRT4 | GeneProduct | ENSG00000089163 (Ensembl) | |
SIRT5 | GeneProduct | ENSG00000124523 (Ensembl) | |
SIRT6 | GeneProduct | ENSG00000077463 (Ensembl) | |
SIRT7 | GeneProduct | ENSG00000187531 (Ensembl) | |
TCA Cycle | Pathway | WP73 (WikiPathways) | |
dATP | Metabolite | HMDB0001532 (HMDB) |
Annotated Interactions
No annotated interactions