If an enzyme name is shown in bold, there is experimental evidence for this enzymatic activity.
Locations of Mapped Genes:
|Superclasses:||Biosynthesis → Fatty Acids and Lipids Biosynthesis → Sterol Biosynthesis|
Pathway Summary from MetaCyc:
The sequence of reactions in the cholesterol biosynthetic pathway may vary. This superpathway gives an overview of three possible routes of cholesterol biosynthesis. These routes exist because reduction of the carbon 24,25 double bond on the hydrocarbon side chain of the sterol ring structure by sterol Δ24-reductase can occur at multiple points in the pathway, giving rise to different intermediates. These intermediates, with or without a double bond in the hydrocarbon side chain, can serve as substrates for the other enzymes in the pathway. However, there is evidence that the preferred point of carbon 24,25 double bond reduction is directly after the isomerization of zymosterol [ Bae97 ], as shown in pathway cholesterol biosynthesis I . In [ Waterham01 ] and reviewed in [ Gaylor02 ].
Subpathways: trans, trans-farnesyl diphosphate biosynthesis , mevalonate pathway I , cholesterol biosynthesis III (via desmosterol) , cholesterol biosynthesis II (via 24,25-dihydrolanosterol) , cholesterol biosynthesis I , lanosterol biosynthesis , epoxysqualene biosynthesis
Variants: bile acid biosynthesis, neutral pathway
Bae97: Bae SH, Paik YK (1997). "Cholesterol biosynthesis from lanosterol: development of a novel assay method and characterization of rat liver microsomal lanosterol delta 24-reductase." Biochem J 326 ( Pt 2);609-16. PMID: 9291139
Waterham01: Waterham HR, Koster J, Romeijn GJ, Hennekam RC, Vreken P, Andersson HC, FitzPatrick DR, Kelley RI, Wanders RJ (2001). "Mutations in the 3beta-hydroxysterol Delta24-reductase gene cause desmosterolosis, an autosomal recessive disorder of cholesterol biosynthesis." Am J Hum Genet 69(4);685-94. PMID: 11519011