LBR
LBR (lamin B receptor, also known as DHCR14B or TDRD18) is an inner nuclear membrane protein that combines two roles: it catalyses a step in cholesterol biosynthesis and it anchors the nuclear lamina and heterochromatin to the nuclear envelope. Browse Assay Genie's current range of LBR research reagents below, or read on for the biology behind the target.
LBR is a bifunctional membrane protein. As an enzyme, it catalyses the reduction of the C14-unsaturated bond of lanosterol, a step in the metabolic pathway leading to cholesterol biosynthesis. This activity is important in myeloid cells, where LBR-dependent cholesterol biosynthesis is essential for both growth and functional maturation. LBR also mediates the activation of NADPH oxidases, perhaps by maintaining the cholesterol levels needed for membrane lipid raft formation during neutrophil differentiation.
Structurally and functionally, LBR also acts as a nuclear envelope anchor. It sits in the inner nuclear membrane and tethers the lamina and heterochromatin to it, and it may mediate the interaction between chromatin and lamin B. UniProt lists its locations as the nucleus inner membrane, endoplasmic reticulum membrane, cytoplasm and nucleus. The LBR protein belongs to the ERG4/ERG24 family, and HGNC places the gene in the Tudor domain containing and dehydrocholesterol reductase groups, which is reflected in the alias TDRD18 and the alias DHCR14B.
Mutations in the LBR gene have been associated with autosomal recessive HEM/Greenberg skeletal dysplasia. According to the NCBI Gene summary, alternative splicing at this locus yields two transcript variants that encode the same protein. Mouse and rat each have an ortholog named Lbr, so the protein can be studied in common rodent models, although you should check the datasheet of any LBR antibody or LBR ELISA kit for its validated reactivity.
LBR reduces the C14-unsaturated bond of lanosterol, making it a useful entry point for studying the late steps of cholesterol synthesis.
LBR-dependent cholesterol biosynthesis is essential for myeloid cell growth and functional maturation, including neutrophil differentiation.
LBR anchors the lamina and heterochromatin to the inner nuclear membrane and may mediate chromatin and lamin B interaction.
Mutations in LBR are associated with autosomal recessive HEM/Greenberg skeletal dysplasia, linking the gene to a human genetic disease.
LBR catalyses the reduction of the C14-unsaturated bond of lanosterol in the cholesterol biosynthesis pathway. It also anchors the nuclear lamina and heterochromatin to the inner nuclear membrane, and it supports NADPH oxidase activation during neutrophil differentiation, perhaps by maintaining cholesterol for lipid rafts.
LBR stands for lamin B receptor. Its UniProt protein name is Delta(14)-sterol reductase LBR, and aliases include DHCR14B and TDRD18. NCBI reports two transcript variants from alternative splicing, and both encode the same protein.
Mutations in the LBR gene are associated with autosomal recessive HEM/Greenberg skeletal dysplasia. Orthologs named Lbr exist in mouse and rat. Check the datasheet of any product for its validated reactivity.
Other sterol-biosynthesis enzymes, nuclear envelope proteins and lamin-associated targets with products at Assay Genie.
Gene and protein annotations from HGNC, NCBI Gene and UniProt Q14739; product specifications from Assay Genie datasheets.