The LBR gene provides instructions for making a protein called the lamin B receptor. Different regions (domains) of this protein give it two distinct functions.
One region of the protein, called the sterol reductase domain, gives the protein sterol reductase function (specifically Δ14-sterol reductase function). This function of the lamin B receptor plays an important role in the production (synthesis) of cholesterol. Cholesterol is a lipid (fat) that is obtained from foods that come from animals: eggs, meat, fish, and dairy products. The body also makes (synthesizes) its own cholesterol. During cholesterol synthesis, the sterol reductase function of the lamin B receptor allows the protein to perform one of several chemical reactions that convert a molecule called lanosterol to cholesterol.
The body needs cholesterol to develop and function normally. Before birth, cholesterol interacts with signaling proteins that control early development of the brain, limbs, genitals, and other structures. It is also an important component of cell membranes and myelin, the fatty covering that insulates nerve cells. Additionally, cholesterol is used to make certain hormones and is important for the production of acids used in digestion (bile acids).
Another region of the lamin B receptor, called the DNA-binding domain, attaches (binds) to chromatin, the complex of DNA and proteins that packages DNA into chromosomes. The lamin B receptor can be found in the membrane that surrounds the nucleus (the nuclear envelope). The protein’s interaction with chromatin attaches it to the nuclear envelope and helps maintain the chromatin’s structure. Proper interaction of chromatin with the nuclear envelope may play a role in several important cellular functions such as making new copies of DNA (replication), controlling the activity of genes, and regulating programmed cell death (apoptosis). The DNA-binding domain of the protein also plays a role in the formation of the nucleus within cells.
Other Names
DHCR14B; integral nuclear envelope inner membrane protein; lamin-B receptor; LBR_HUMAN; LMN2R; PHA; TDRD18
Related Genetics Topics
Identifiers
- NCBI Gene: 3930
- OMIM: 169400
- OMIM: 600024
Source: MedlinePlus Genetics, U.S. National Library of Medicine.
