PathwayStep1918 PathwayStep1919 PathwayStep1916 PathwayStep1917 PathwayStep1914 PathwayStep1915 PathwayStep1927 PathwayStep1928 PathwayStep1929 PathwayStep1923 PathwayStep1924 PathwayStep1925 PathwayStep1926 PathwayStep1920 PathwayStep1921 PathwayStep1922 PathwayStep1932 PathwayStep1930 PathwayStep1931 LTA4 is hydrolysed to 6t-/6t,12epi-LTB4 LTA4 is converted to EXA4 by ALOX15 EXA4 is converted to EXC4 by LTC4S LTA4 is converted to LTC4 by LTC4S ABCC1 mediates LTC4 export from the cell LTC4 is converted to LTD4 by GGT1/5 Further cleavage of LTD4 forms LTE4 20cho-LTB4 is oxidised to 20cooh-LTB4 by CYP4F2/4F3 20cho-LTB4 is oxidised to 20cooh-LTB4 by ALDH 20cooh-LTB4 is converted to 18cooh-LTB4 EXD4 is converted to EXE4 by DPEP EXC4 is converted to EXD4 by GGT 20oh-LTB4 is oxidised to 20cho-LTB4 by CYP4F2/4F3 5S-HpETE is dehydrated to LTA4 by ALOX5 LTA4 is hydrolyzed to LTB4 LTB4 is oxidised to 12-oxoLTB4 by PTGR1 LTB4 is hydroxylated to 20oh-LTB4 by CYP4F2/4F3 ALOX5 is phosphorylated by MAPKAP2 Oxidation of arachidonic acid to 5-HpETE Synthesis of Leukotrienes (LT) and Eoxins (EX) Authored: Williams, MG, 2012-02-24 Edited: Williams, MG, 2012-02-24 GENE ONTOLOGYGO:0006691 ISBN978-0-444-53219-0 Leukotrienes (LTs) are biologically active molecules formed in response to inflammatory stimuli. They cause contraction of bronchial smooth muscles, stimulation of vascular permeability, and attraction and activation of leukocytes. LTs were discovered in 1938 and were termed the "slow release substance" (SRS) until their structures were determined in 1979 and they were then renamed to leukotrienes. LTs are derived from arachidonic acid through action by arachidonate 5-lipoxygenase (ALOX5). Cysteinyl leukotrienes (LTC4, LTD4, and LTE4) are generated as products derived from leukotriene A4 (LTA4). Eoxins are generated from leukotrienes (LTs) and resemble cysteinyl leukotrienes but have a different three-dimensional structure (Murphy & Gijon 2007, Hammarstrom 1983, MA.Claesson 2009, Vance & Vance 2008, Buczynski et al. 2009). Pubmed17623009 Pubmed19130894 Pubmed19244215 Pubmed6311078 Reactome Database ID Release 432142691 Reactome, http://www.reactome.org ReactomeREACT_150420 Reviewed: Rush, MG, 2012-11-10