Heme biosynthesis (WP1221)

Anopheles gambiae

The enzymatic process that produces heme is properly called porphyrin synthesis, as all the intermediates are tetrapyrroles that are chemically classified are porphyrins. The process is highly conserved across biology. In humans, this pathway serves almost exclusively to form heme. In other species, it also produces similar substances such as cobalamin (vitamin B12). The pathway is initiated by the synthesis of D-Aminolevulinic acid (dALA or δALA) from the amino acid glycine and succinyl-CoA from the citric acid cycle (Krebs cycle). The rate-limiting enzyme responsible for this reaction, ALA synthase, is strictly regulated by intracellular iron levels and heme concentration. A low-iron level, e.g., in iron deficiency, leads to decreased porphyrin synthesis, which prevents accumulation of the toxic intermediates. This mechanism is of therapeutic importance: infusion of heme arginate or hematin can abort attacks of porphyria in patients with an inborn error of metabolism of this process, by reducing transcription of ALA synthase. The organs mainly involved in heme synthesis are the liver and the bone marrow, although every cell requires heme to function properly. Heme is seen as an intermediate molecule in catabolism of haemoglobin in the process of bilirubin metabolism. Source: Wikipedia http://en.wikipedia.org/wiki/Heme

Authors

Caroline Miller , Egon Willighagen , Martina Summer-Kutmon , Jonathan Mélius , and Eric Weitz

Activity

last edited

Discuss this pathway

Check for ongoing discussions or start your own.

Cited In

Are you planning to include this pathway in your next publication? See How to Cite and add a link here to your paper once it's online.

Organisms

Anopheles gambiae

Communities

Annotations

Pathway Ontology

heme biosynthetic pathway

Participants

Label Type Compact URI Comment
O2 Metabolite hmdb:HMDB0001377
NH3 Metabolite hmdb:HMDB0000051
H2O2 Metabolite hmdb:HMDB0003125
CoA Metabolite hmdb:HMDB0001423
CO2 Metabolite hmdb:HMDB0001967
H2O Metabolite hmdb:HMDB0002111
Porphobilinogen Metabolite hmdb:HMDB0000245
AgaP_AGAP003719 GeneProduct ncbigene:1271452
AgaP_AGAP003704 GeneProduct ncbigene:1274381
AgaP_AGAP004749 GeneProduct ncbigene:1278476
AgaP_AGAP011080 GeneProduct ncbigene:3291232
AgaP_AGAP003184 GeneProduct ncbigene:1273856
AgaP_AGAP010935 GeneProduct ncbigene:1271017
AgaP_AGAP008064 GeneProduct ncbigene:1277887
AgaP_AGAP011895 GeneProduct ncbigene:1280765

References