LBR Antibodies

Structure of LBR

LBR is a nuclear membrane protein with a molecular weight of approximately 58-60kDa, and its size varies among different species:

LBR is composed of approximately 600 amino acids and has a unique dual-domain feature. The N-terminal nucleoplasmic domain (amino acids 1-208) of this protein contains multiple functional modules, including a serine/arginine-rich sequence and nuclear localization signals. The C-terminal transmembrane domain (amino acids 209-600) contains 8 transmembrane segments, forming a hydrophobic core with sterol reductase activity.

Fig. 1 Schematic illustration of full-length LBR.¹

Key structural properties of LBR:

• Dual-functional domains: The core-mass domain and the transmembrane domain perform functions independently
• Amino acids 71-100: DNA binding region (containing SR-enriched sequence)
• Transmembrane region: NADPH binding site (Gly X-X-X-Gly motif)
• Nuclear plasmic domain: Binding site of nuclear lamellar protein B
• Multiple phosphorylation sites: Regulate protein function

Functions of LBR

The main function of LBR is to maintain the nuclear membrane structure and chromatin organization, and at the same time participate in various cellular physiological processes.

The binding curve of LBR and chromatin shows a typical synergistic effect, indicating that its multiple binding sites can cooperatively regulate the chromatin - nuclear membrane interaction. Unlike simple DNA-binding proteins, LBR can not only recognize specific chromatin markers but also affect membrane fluidity through the sterol reductase domain, achieving dual regulation of structure and metabolic functions.

Applications of LBR and LBR Antibody in Literature

1. Ye, Qian, and Howard J. Worman. "Primary structure analysis and lamin B and DNA binding of human LBR, an integral protein of the nuclear envelope inner membrane." Journal of Biological Chemistry 269.15 (1994): 11306-11311. https://doi.org/10.1016/S0021-9258(19)78126-5

This article indicates that the human nuclear membrane protein LBR interacts with laminin B and DNA. Its amino terminal contains a Ser-ArG-rich region, which can be recognized by autoantibodies and can bind to DNA (the key amino acids of 71-100). LBR plays an important role in the anchoring of the nuclear lamina and chromatin.

2. Schuler, Ekkehard, Feng Lin, and Howard J. Worman. "Characterization of the human gene encoding LBR, an integral protein of the nuclear envelope inner membrane." Journal of Biological Chemistry 269.15 (1994): 11312-11317. https://doi.org/10.1016/S0021-9258(19)78127-7

The research found that the human nuclear membrane protein LBR gene spans 35kb and contains 13 exons (1-4 encode the nucleoplasmic domain, and 5-13 encode the transmembrane region). Its 5' end contains multiple transcription factor binding sites, and the transmembrane region is homologous to yeast protein, suggesting that this gene may have evolved from the recombination of nuclear protein and membrane protein genes.

3. Ye, Qian, and Howard J. Worman. "Interaction between an integral protein of the nuclear envelope inner membrane and human chromodomain proteins homologous to Drosophila HP1." Journal of Biological Chemistry 271.25 (1996): 14653-14656. https://doi.org/10.1074/jbc.271.25.14653

Research has found that the nuclear membrane protein LBR can bind to the heterochromatin protein HP1, revealing that it mediates the adhesion of heterochromatin to the nuclear intima through the amino-terminal domain. LBR, as a bidirectional anchoring protein between the nuclear lamina and chromatin, plays a key role in maintaining the structural integrity of the nuclear membrane.

4. Tsai, Pei-Ling, et al. "The Lamin B receptor is essential for cholesterol synthesis and perturbed by disease-causing mutations." Elife 5 (2016): e16011. https://doi.org/10.7554/eLife.16011

Studies have found that the nuclear membrane protein LBR is crucial for cholesterol synthesis. LBR mutations can lead to poor skeletal development and Pelger-Huet abnormalities in Greenberg. The mechanisms are divided into two categories: Sterol reductase domain mutations reduce NADPH affinity, while truncation mutations cause rapid protein degradation. These mutants provide a new model for the study of endonuclear protein metabolism.

5. Simos, George, Christèle Maison, and Spyros D. Georgatos. "Characterization of p18, a component of the lamin B receptor complex and a new integral membrane protein of the avian erythrocyte nuclear envelope." Journal of Biological Chemistry 271.21 (1996): 12617-12625. https://doi.org/10.1074/jbc.271.21.12617

Studies have found that mutations in the nuclear membrane protein LBR gene can induce lupus-like autoimmune responses. F1 female mice carrying Lbr mutations (NZW×B6.Lbric) showed splenomegaly, renal injury and high-titer anti-chromatin antibodies (mainly IgG2 subtype), and their antinuclear antibodies presented a complex reaction pattern of nuclear membrane and histone, suggesting that abnormal nuclear structure can promote the occurrence of lupus under the background of genetic susceptibility.

Creative Biolabs: LBR Antibodies for Research

Creative Biolabs specializes in the production of high-quality LBR antibodies for research and industrial applications. Our portfolio includes monoclonal antibodies tailored for Western Blot, IF, IHC, and other diagnostic methodologies.

• Custom LBR Antibody Development: Tailor-made solutions to meet specific research requirements.
• Bulk Production: Large-scale antibody manufacturing for industry partners.
• Technical Support: Expert consultation for protocol optimization and troubleshooting.
• Aliquoting Services: Conveniently sized aliquots for long-term storage and consistent experimental outcomes.

For more details on our myoglobin antibodies, custom preparations, or technical support, contact us at info@creative-biolabs.com.