title: CYP7B1: one cytochrome P450, two human genetic diseases, and multiple physiological functions.
abstract: The CYP7B1 cytochrome P450 enzyme hydroxylates carbons 6 and 7 of the B ring of oxysterols and steroids. Hydroxylation reduces the biological activity of these substrates and facilitates their conversion to end products that are readily excreted from the body. CYP7B1 is expressed in the liver, reproductive tract, and brain and performs different physiological functions in each tissue. Hepatic CYP7B1 activity is crucial for the inactivation of oxysterols and their subsequent conversion into bile salts. Loss of CYP7B1 activity is associated with liver failure in children. In the reproductive tract, the enzyme metabolizes androgens that antagonize estrogen action; mice without CYP7B1 have abnormal prostates and ovaries. The role of CYP7B1 in brain is under investigation; recent studies show that spastic paraplegia type 5, a progressive neuropathy, is caused by loss-of-function mutations in the human gene.
authors.affiliation: Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9046, USA.
authors.forename: Ashlee R
authors.initials: AR
authors.lastname: Stiles
authors.forename: Jeffrey G
authors.initials: JG
authors.lastname: McDonald
authors.forename: David R
authors.initials: DR
authors.lastname: Bauman
authors.forename: David W
authors.initials: DW
authors.lastname: Russell
mesh_terms: D000818:Animals; D001234:Aspergillus niger / Q000378:metabolism; D002648:Child; D000072474:Cytochrome P450 Family 7; D006801:Humans; D007136:Immunoglobulins / Q000378:metabolism; D008024:Ligands; D017093:Liver Failure / Q000175:diagnosis / Q000235:genetics*; D051379:Mice; D008956:Models, Chemical; D009422:Nervous System Diseases / Q000175:diagnosis / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D013250:Steroid Hydroxylases / Q000235:genetics* / Q000502:physiology*; D013256:Steroids / Q000378:metabolism
chemical_list: D007136:Immunoglobulins; D008024:Ligands; D012333:RNA, Messenger; D013256:Steroids; D013250:Steroid Hydroxylases; D000072474:Cytochrome P450 Family 7; C499571:CYP7B1 protein, human; C097207:Cyp7b1 protein, mouse
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