| UID:bsid105711 | | , , , ,  |
COX reactions- Type : organism-specific biosystem
- Description : Arachidonic acid (AA) is a 20 carbon unsaturated fatty acid which is present in
the lipid bilayer of all mammalian cells. AA is released from the membrane by
phospholipases, thus making it available for conversion to bioactive lipids. The
cyclooxygenase pathway is one of three pathways (the others being lipoxygenase
and P450 monooxygenase pathways) that perform this conversion.\n\nThe enzyme that
acts in the cyclooxygenase pathway is called cyclooxygenase (COX) or
prostaglandin H synthase (PGHS). PGHS exhibits a dual catalytic activity, a
cyclooxygenase and a peroxidase. The cyclooxygenase catalyzes the initial
conversion of AA to an intermediate, prostaglandin G2 (PGG2) whilst the
peroxidase converts PGG2 to prostaglandin H2 (PGH2) via a two-electron reduction.
PGH2 is the intermediate for products that play critical roles in immune function
regulation, kidney development and mucosal integrity of the GI tract.\n\nPGHS
exists in two isoforms, 1 and 2 and both forms can perform the above reactions.
Form 1 is constitutively expressed in most tissues and is involved in performing
normal physiological functions. Form 2, in contrast, is inducible and is involved
in critical steps of rheumatic disease, inflammation and tumorigenesis.
- Organism: Homo sapiens
- Source : REACTOME [REACT_1396]
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