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 respiratory chain (ETC), 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. NADK, NAD+ kinase.
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 |
---|---|---|---|
?NMNAT3 | GeneProduct | ENSG00000163864 (Ensembl) | |
ART | GeneProduct | ||
CD38 | GeneProduct | ENSG00000004468 (Ensembl) | |
CD73 | GeneProduct | ENSG00000135318 (Ensembl) | |
ETC | Pathway | ||
FADH2 | Metabolite | ||
FADH | Metabolite | HMDB01197 (HMDB) | |
Glyceraldehyde 3-phosphate shuttle | Pathway | ||
Glycolysis | Pathway | WP534 (WikiPathways) | |
L-Tryptophan (TRP) | Metabolite | HMDB00929 (HMDB) | |
Lactate | Metabolite | HMDB00190 (HMDB) | |
Malate/aspartate shuttle | Pathway | ||
NAD+ | Metabolite | HMDB00902 (HMDB) | |
NADH | Metabolite | HMDB01487 (HMDB) | |
NAD | Metabolite | HMDB00902 (HMDB) | |
NADK | GeneProduct | ENSG00000008130 (Ensembl) | |
NADPH | Metabolite | HMDB00221 (HMDB) | |
NADP | Metabolite | HMDB00217 (HMDB) | |
NA | Metabolite | HMDB01488 (HMDB) | |
NAM | Metabolite | HMDB01406 (HMDB) | |
NAMN | Metabolite | HMDB01132 (HMDB) | |
NAMPT | GeneProduct | ENSG00000105835 (Ensembl) | |
NMN | Metabolite | 13553 (Chemspider) | |
NMNAT1 | GeneProduct | ENSG00000173614 (Ensembl) | |
NMNAT2 | GeneProduct | ENSG00000157064 (Ensembl) | |
NR | Metabolite | HMDB00855 (HMDB) | |
NRK | GeneProduct | ENSG00000123572 (Ensembl) | |
Nicotinic acid (NA) | Metabolite | HMDB01488 (HMDB) | |
PARP1 | GeneProduct | ENSG00000143799 (Ensembl) | |
PRPP | Metabolite | HMDB00280 (HMDB) | |
Pyruvate | Metabolite | HMDB00243 (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) | |
TRP | Metabolite | HMDB00929 (HMDB) | |
dATP | Metabolite | HMDB01532 (HMDB) |
Annotated Interactions
No annotated interactions