Prostacyclin synthase

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prostaglandin-I synthase
Prostacyclin synthase 2IAG Chiang et al.png
Cartoon diagram of human prostacyclin synthase. Heme group visible at center. From PDB: 2IAG
EC number5.3.99.4
CAS number65802-86-0
IntEnzIntEnz view
ExPASyNiceZyme view
MetaCycmetabolic pathway
PDB structuresRCSB PDB PDBe PDBsum
Gene OntologyAmiGO / QuickGO
PDB 2iag EBI.png
Available structures
PDBOrtholog search: PDBe RCSB
AliasesPTGIS, CYP8, CYP8A1, PGIS, PTGI, prostaglandin I2 (prostacyclin) synthase, prostaglandin I2 synthase
External IDsOMIM: 601699 MGI: 1097156 HomoloGene: 37374 GeneCards: PTGIS
Gene location (Human)
Chromosome 20 (human)
Chr.Chromosome 20 (human)[1]
Chromosome 20 (human)
Genomic location for PTGIS
Genomic location for PTGIS
Band20q13.13Start49,503,874 bp[1]
End49,568,137 bp[1]
RefSeq (mRNA)



RefSeq (protein)



Location (UCSC)Chr 20: 49.5 – 49.57 MbChr 2: 167.19 – 167.24 Mb
PubMed search[3][4]
View/Edit HumanView/Edit Mouse

Prostaglandin-I synthase (EC also known as prostaglandin I2 (prostacyclin) synthase (PTGIS) or CYP8A1 is an enzyme involved in prostanoid biosynthesis that in humans is encoded by the PTGIS gene.[5] This enzyme belongs to the family of cytochrome P450 isomerases.


This gene encodes a member of the cytochrome P450 superfamily of enzymes. The cytochrome P450 proteins are monooxygenases which catalyze many reactions involved in drug metabolism and synthesis of cholesterol, steroids and other lipids. However, this protein is considered a member of the cytochrome P450 superfamily on the basis of sequence similarity rather than functional similarity. This endoplasmic reticulum membrane protein catalyzes the conversion of prostaglandin H2 to prostacyclin (prostaglandin I2), a potent vasodilator and inhibitor of platelet aggregation. An imbalance of prostacyclin and its physiological antagonist thromboxane A2 contribute to the development of myocardial infarction, stroke, and atherosclerosis.[6]

Unlike most P450 enzymes, PGIS does not require molecular oxygen (O2). Instead it uses its heme cofactor to catalyze the isomerization of prostaglandin H2 to prostacyclin. Prostaglandin H2 is produced by cyclooxygenase in the first committed step of prostaglandin biosynthesis.


The systematic name of this enzyme class is (5Z,13E)-(15S)-9alpha,11alpha-epidioxy-15-hydroxyprosta-5,13-dienoate 6-isomerase. Other names in common use include prostacyclin synthase, prostacyclin synthetase, prostagladin I2 synthetase, PGI2 synthase, PGIS, PTGIS, and PGI2 synthetase.


Thromboxane synthesis
Eicosanoid synthesis.

See also[edit]


  1. ^ a b c GRCh38: Ensembl release 89: ENSG00000124212 - Ensembl, May 2017
  2. ^ a b c GRCm38: Ensembl release 89: ENSMUSG00000017969 - Ensembl, May 2017
  3. ^ "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  4. ^ "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  5. ^ Yokoyama C, Yabuki T, Inoue H, Tone Y, Hara S, Hatae T, Nagata M, Takahashi EI, Tanabe T (September 1996). "Human gene encoding prostacyclin synthase (PTGIS): genomic organization, chromosomal localization, and promoter activity". Genomics. 36 (2): 296–304. doi:10.1006/geno.1996.0465. PMID 8812456.
  6. ^ "Entrez Gene: PTGIS".

Further reading[edit]

External links[edit]

This article incorporates text from the United States National Library of Medicine, which is in the public domain.