LBR : lamin B receptor
Description
The LBR (lamin B receptor) is a protein-coding gene located on chromosome 1.
The LBR gene provides instructions for making a protein called the lamin B receptor. This protein has two distinct functions, determined by different regions (domains). The sterol reductase domain gives the protein its sterol reductase activity, specifically Δ14-sterol reductase function, which is essential for cholesterol production. Cholesterol, a lipid obtained from animal products and synthesized by the body, plays a crucial role in development and normal function. The sterol reductase activity of LBR facilitates the conversion of lanosterol to cholesterol. The other region, the DNA-binding domain, attaches to chromatin, the complex of DNA and proteins that package DNA into chromosomes. Found in the nuclear envelope, this domain interacts with chromatin, connecting it to the nuclear envelope and maintaining its structure. This interaction is crucial for various cellular processes including DNA replication, gene regulation, and programmed cell death. The DNA-binding domain also plays a role in the formation of the nucleus within cells.
The LBR protein catalyzes the reduction of the C14-unsaturated bond of lanosterol, a crucial step in the cholesterol biosynthesis pathway. It plays a critical role in myeloid cell cholesterol biosynthesis, essential for both cell growth and functional maturation. This protein may also mediate the activation of NADPH oxidases by maintaining critical cholesterol levels needed for membrane lipid raft formation during neutrophil differentiation. LBR anchors the lamina and heterochromatin to the inner nuclear membrane.
LBR is also known as C14SR, DHCR14B, LMN2R, PHA, PHASK, TDRD18.
Associated Diseases
- Reynolds syndrome
- Greenberg skeletal dysplasia
- Rhizomelic skeletal dysplasia with or without Pelger-Huet anomaly
- Greenberg dysplasia
- Pelger-Huet anomaly
