DHCR7
DHCR7 (7-dehydrocholesterol reductase) is an endoplasmic reticulum membrane enzyme that catalyses the conversion of 7-dehydrocholesterol to cholesterol. The gene is also known as SLOS, after Smith-Lemli-Opitz syndrome, the disorder caused by its mutation. Browse Assay Genie's current range of DHCR7 research reagents below, or read on for the biology behind the target.
DHCR7 is an enzyme that removes the C(7-8) double bond in the B ring of sterols, catalysing the conversion of 7-dehydrocholesterol to cholesterol. It therefore acts at the final stage of cholesterol biosynthesis. The protein also has a structural role in a second activity: together with cholestenol Delta-isomerase (EBP), it forms part of the microsomal antiestrogen binding site (AEBS), a multiprotein complex in the endoplasmic reticulum membrane. This complex has cholesterol-5,6-epoxide hydrolase (ChEH) activity, hydrating cholesterol-5,6-epoxides into cholestane-3beta,5alpha,6beta-triol. Within the complex, DHCR7 cooperates in substrate binding, while EBP carries the catalytic activity.
The DHCR7 gene is ubiquitously expressed. Its transmembrane protein localises to the endoplasmic reticulum membrane and the nuclear outer membrane. The protein belongs to the ERG4/ERG24 family and is classed by HGNC among the dehydrocholesterol reductases and the AEBS complex subunits. Alternative splicing produces multiple transcript variants that all encode the same protein. Mouse and rat orthologs are both named Dhcr7.
Mutations in the DHCR7 gene cause Smith-Lemli-Opitz syndrome (SLOS), which is why SLOS is listed as an alias and the syndrome name as a previous gene name. The condition is metabolically characterised by reduced serum cholesterol and elevated serum 7-dehydrocholesterol. Its phenotype ranges from cognitive disability, facial dysmorphism, syndactyly of the second and third toes and, in severe cases, holoprosencephaly, to minimal physical abnormalities and near-normal intelligence in mild cases. This makes DHCR7 a useful focus for work on cholesterol metabolism and developmental disease.
DHCR7 converts 7-dehydrocholesterol to cholesterol, making it a key enzyme for studying the terminal steps of sterol synthesis.
Mutations in DHCR7 cause SLOS, marked by low serum cholesterol and raised 7-dehydrocholesterol, so the protein is central to studying this disorder.
DHCR7 and EBP together form the AEBS complex, in which DHCR7 aids substrate binding for cholesterol-5,6-epoxide hydrolase activity.
As a transmembrane ERG4/ERG24 family member in the ER and nuclear outer membrane, DHCR7 is relevant to sterol-metabolising membrane proteins.
DHCR7 removes the C(7-8) double bond in the sterol B ring, converting 7-dehydrocholesterol to cholesterol. It also forms part of the antiestrogen binding site complex with EBP, where it helps bind substrates for cholesterol-5,6-epoxide hydrolase activity.
SLOS is an alias taken from Smith-Lemli-Opitz syndrome, which results from mutations in the gene. HGNC lists the syndrome name as a previous name. Alternative splicing gives several transcript variants, but all encode the same protein.
Mouse and rat both have a Dhcr7 ortholog. In humans, DHCR7 mutations cause Smith-Lemli-Opitz syndrome, with reduced serum cholesterol and raised 7-dehydrocholesterol; check the datasheet of any product for its validated reactivity.
Other sterol biosynthesis enzymes and partners of the antiestrogen binding site complex.
Gene and protein annotations from HGNC, NCBI Gene and UniProt Q9UBM7; product specifications from Assay Genie datasheets.