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serpin family E member 1

Normal Function

The SERPINE1 gene provides instructions for making a protein called plasminogen activator inhibitor 1 (PAI-1). PAI-1 is involved in normal blood clotting (hemostasis). After an injury, clots protect the body by sealing off damaged blood vessels and preventing further blood loss.

The PAI-1 protein blocks (inhibits) the action of other proteins called plasminogen activators. These proteins, including urokinase plasminogen activator (u-PA) and tissue type plasminogen activator (t-PA), convert an inactive enzyme called plasminogen to its active form, plasmin. Plasmin is involved in fibrinolysis, which is the process of dissolving blood clots. By inhibiting the conversion of plasminogen to plasmin, and thereby preventing fibrinolysis, the PAI-1 protein helps ensure that clots are only dissolved when they are no longer needed to stop bleeding.

In addition to its role in hemostasis, PAI-1 is also thought to be involved in cell movement (migration) and the breakdown and replacement (remodeling) of body tissues.

Health Conditions Related to Genetic Changes

Complete plasminogen activator inhibitor 1 deficiency

At least three SERPINE1 gene mutations have been identified in people with complete plasminogen activator inhibitor 1 (PAI-1) deficiency, a disorder that causes abnormal bleeding. In people with this disorder, bleeding after an injury can be excessive and last longer than usual. Affected females may have excessive bleeding associated with menstruation (menorrhagia), and abnormal bleeding in pregnancy and childbirth.

The SERPINE1 gene mutations that cause complete PAI-1 deficiency result in impaired production of the PAI-1 protein, or lead to production of PAI-1 protein that is nonfunctional or that is unstable and quickly broken down. Absence of functional PAI-1 protein allows plasminogen activators to dissolve blood clots prematurely, resulting in the abnormal bleeding associated with this disorder.

More About This Health Condition

Other Names for This Gene

  • endothelial plasminogen activator inhibitor
  • PAI
  • PAI-1
  • PAI1
  • PLANH1
  • plasminogen activator inhibitor 1 precursor
  • serine (or cysteine) proteinase inhibitor, clade E (nexin, plasminogen activator inhibitor type 1), member 1
  • serpin E1
  • serpin peptidase inhibitor, clade E (nexin, plasminogen activator inhibitor type 1), member 1

Additional Information & Resources

Tests Listed in the Genetic Testing Registry

Scientific Articles on PubMed

Gene and Variant Databases


  • Asselbergs FW, Pattin K, Snieder H, Hillege HL, van Gilst WH, Moore JH. Genetic architecture of tissue-type plasminogen activator and plasminogen activator inhibitor-1. Semin Thromb Hemost. 2008 Sep;34(6):562-8. doi: 10.1055/s-0028-1103367. Epub 2008 Nov 28. Citation on PubMed
  • Fay WP, Parker AC, Condrey LR, Shapiro AD. Human plasminogen activator inhibitor-1 (PAI-1) deficiency: characterization of a large kindred with a null mutation in the PAI-1 gene. Blood. 1997 Jul 1;90(1):204-8. Citation on PubMed
  • Flevaris P, Vaughan D. The Role of Plasminogen Activator Inhibitor Type-1 in Fibrosis. Semin Thromb Hemost. 2017 Mar;43(2):169-177. doi: 10.1055/s-0036-1586228. Epub 2016 Aug 24. Citation on PubMed
  • Heiman M, Gupta S, Lewandowska M, Shapiro AD. Complete Plasminogen Activator Inhibitor 1 Deficiency. 2017 Aug 3 [updated 2023 Feb 23]. In: Adam MP, Feldman J, Mirzaa GM, Pagon RA, Wallace SE, Bean LJH, Gripp KW, Amemiya A, editors. GeneReviews(R) [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2024. Available from Citation on PubMed
  • Mehta R, Shapiro AD. Plasminogen activator inhibitor type 1 deficiency. Haemophilia. 2008 Nov;14(6):1255-60. doi: 10.1111/j.1365-2516.2008.01834.x. Citation on PubMed
  • Yasar Yildiz S, Kuru P, Toksoy Oner E, Agirbasli M. Functional stability of plasminogen activator inhibitor-1. ScientificWorldJournal. 2014;2014:858293. doi: 10.1155/2014/858293. Epub 2014 Oct 15. Citation on PubMed or Free article on PubMed Central

The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.