Steroid biosynthesis - Homo sapiens (human)

Curator(s): Joe Strothman

Steroidogenesis is the biological process by which steroids are generated from cholesterol and transformed into other steroids. Steroids include estrogen, cortisol, progesterone, and testosterone. Estrogen and progesterone are made primarily in the ovary and in the placenta during pregnancy, and testosterone in the testes. Testosterone is also converted into estrogen to regulate the supply of each, in the bodies of both females and males. Certain neurons and glia in the central nervous system (CNS) express the enzymes that are required for the local synthesis of pregnane neurosteroids, either de novo or from peripherally-derived sources. The rate-limiting step of steroid synthesis is the conversion of cholesterol to pregnenolone, which occurs inside the mitochondrion.    
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Steroid biosynthesis - Homo sapiens (human) cluster_Hopane Hopane node1 Farnesyl-PP node2 node1->node2 node3 Presqualene-PP node2->node3 Squalene node2->Squalene node3->node2 node4 Squalene->node4 node5 Squalene->node5 Tetrahymanol Squalene->Tetrahymanol node10 1 node4->node10 node6 (S) -Squalene -2,3-epoxide node5->node6 node7 node6->node7 Triterpenoid node6->Triterpenoid node11 node6->node11 Cycloartenol node7->Cycloartenol SMT1 Cycloartenol->SMT1 node8 24-Methylenecycloartanol SMT1->node8 SMO1 node8->SMO1 Cycloeucalenol SMO1->Cycloeucalenol node9 Cycloeucalenol->node9 Obtusifoliol node9->Obtusifoliol CYP51G1 Obtusifoliol->CYP51G1 node39 4alpha -Methyl -5alpha-ergosta -8,14,24(28)-trien -3beta-ol CYP51G1->node39 Terpinoid backbone biosynthesis Terpinoid backbone biosynthesis->node1 Diploptene node10->Diploptene Diplopterol node10->Diplopterol Lanosterol node11->Lanosterol node12 node12->Lanosterol node17 14-Demethyl -lanosterol node12->node17 Zymosterol node12->Zymosterol node23 Cholesta -8 -en-3Beta -ol node12->node23 Latherosterol node12->Latherosterol node25 Cholesta -7,24 -dien-3Beta -ol node12->node25 node28 7-Dehydrocholesterol node12->node28 Cholesterol node12->Cholesterol node36 7-Dehydro -desmosterol node12->node36 Desmosterol node12->Desmosterol node52 24,25 -Dihydro -lanosterol node12->node52 node53 4,4 -Dimethyl -cholestra -8 -en-3beta -ol node12->node53 node13 Lanosterol->node13 node14 4,4 -Dimethyl -cholesta -8,14,24 -trienol node13->node14 node16 node14->node16 node15 node19 4-Methylzymosterol -carboxylate node15->node19 node16->node17 node17->node15 node18 node20 3-Keto -4-methyl -zymosterol node18->node20 node19->node18 node21 node20->node21 node22 4-Methylzymosterol node21->node22 node22->Zymosterol ERG6 Zymosterol->ERG6 node24 Zymosterol->node24 Fecosterol ERG6->Fecosterol node23->node24 node24->Latherosterol node24->node25 node26 Latherosterol->node26 node25->node36 node26->node28 node27 1 node28->node27 7-Dehydrocholesterol Vitamin D3 node28->Vitamin D3 hv node30 node28->node30 cytochrome P450,family 2,subfamily R,polypeptide 1 CYP2R1 Vitamin D3->CYP2R1 Calcidiol CYP2R1->Calcidiol node29 Calcidiol->node29 Calcitriol node29->Calcitriol node30->Cholesterol node34 Cholesterol->node34 Bile acid biosynthesis Cholesterol->Bile acid biosynthesis Steroid hormone metabolism Cholesterol->Steroid hormone metabolism node31 node31->Cholesterol node32 node32->Cholesterol Cholesterol ester node32->Cholesterol ester node33 node33->Cholesterol node33->Cholesterol ester node35 Cholest -4 -en-3 -one node34->node35 node36->Desmosterol Cholesterol ester->node31 ERG2 Fecosterol->ERG2 Episterol ERG2->Episterol ERG3 Episterol->ERG3 node38 5,7,24(28) -Ergosta -trienol ERG3->node38 node37 5,7,24(28) -Ergosta -tetraenol ERG4 node37->ERG4 Ergosterol ERG4->Ergosterol Vitamin D2 Ergosterol->Vitamin D2 hv ERG5 node38->ERG5 ERG5->node37 FK node39->FK node40 4alpha-Methylfecosterol FK->node40 HYD1 node40->HYD1 node41 24-Methylene -lophenol HYD1->node41 SMO2 node41->SMO2 SMT2 node41->SMT2 node42 Episterol (2) SMO2->node42 node44 24-Ethylidene -lophenol SMT2->node44 STE1 node42->STE1 node43 5-Dehydroepisterol STE1->node43 DWF5 node43->DWF5 node49 24-Methylene -cholesterol DWF5->node49 Campesterol Brassinosteroid biosynthesis Campesterol->Brassinosteroid biosynthesis node45 SMO2 (2) node44->node45 node50 Delta7-Avenasterol node45->node50 node46 5-Dehydroavenasterol node47 DWF5 (2) node46->node47 Isofucosterol node47->Isofucosterol node48 DWF1 (2) Isofucosterol->node48 Sitosterol node48->Sitosterol CYP710A Sitosterol->CYP710A Stigmasterol CYP710A->Stigmasterol DWF1 node49->DWF1 DWF1->Campesterol node51 STE1 (2) node50->node51 node51->node46 print "