LBR Gene (Lamin B Receptor): Structure, Function, and Clinical Significance
A comprehensive overview of the LBR gene, its protein product, associated diseases, expression patterns, and mutations.
Gene Information Card
| Symbol | LBR |
|---|---|
| Full Name | Lamin B receptor |
| Gene Type | protein coding |
| Chromosomal Location | 1q42.12 |
| NCBI Gene ID | 3930 ncbi.nlm.nih.gov/gene/3930 |
| Ensembl ID | ENSG00000143815 |
| UniProt ID | Q14739 |
| OMIM ID | 600024 |
| HGNC ID | 6518 |
| Aliases | DHCR14B, LBR, LMNBR, TDRD18 |
Description
The LBR gene encodes the lamin B receptor (LBR), a bifunctional protein that resides in the inner nuclear membrane. It has a lamin B-binding N-terminal domain and a C-terminal sterol reductase domain (similar to DHCR7). LBR is involved in nuclear envelope assembly, chromatin organization, and cholesterol biosynthesis. Mutations in LBR cause autosomal recessive Greenberg dysplasia (a lethal skeletal dysplasia) and autosomal dominant or recessive Pelger-Huët anomaly (a benign nuclear hypolobulation of neutrophils).
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Pelger-Huët anomaly (PHA) | Heterozygous or homozygous mutations in LBR reduce protein function, leading to abnormal nuclear shape and chromatin organization in neutrophils (hypolobulation). | OMIM #169400; ClinVar |
| Greenberg dysplasia (HEM skeletal dysplasia) | Biallelic loss-of-function mutations in LBR impair sterol reductase activity, disrupting cholesterol biosynthesis and bone development. | OMIM #215140; ClinVar |
| Hydrops-ectopic calcification-moth-eaten skeletal dysplasia (HEM) | Same as Greenberg dysplasia; caused by LBR mutations. | OMIM #215140; ClinVar |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Bone marrow | High (nTPM ~ 30) | High expression in hematopoietic cells |
| Liver | Moderate (nTPM ~ 15) | Present in hepatocytes |
| Testis | Moderate (nTPM ~ 12) | Expressed in germ cells |
| Skin | Low (nTPM ~ 5) | Low expression |
| Brain | Low (nTPM ~ 3) | Low expression |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| K-562 (leukemia) | nTPM ~ 25 | High expression; used in hematological studies |
| HeLa (cervical carcinoma) | nTPM ~ 10 | Moderate expression |
| A549 (lung carcinoma) | nTPM ~ 8 | Moderate expression |
| HepG2 (hepatocellular carcinoma) | nTPM ~ 15 | Moderate expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1757G>A (p.Gly586Arg) | Missense | Rare (found in Greenberg dysplasia) | Impairs sterol reductase activity |
| c.1334C>T (p.Pro445Leu) | Missense | Rare (found in Pelger-Huët anomaly) | Disrupts lamin B binding and nuclear envelope localization |
| c.1747C>T (p.Arg583Ter) | Nonsense | Rare (found in Greenberg dysplasia) | Truncated protein, loss of function |
| c.1748G>A (p.Arg583Gln) | Missense | Rare (found in Pelger-Huët anomaly) | Reduced protein stability |
Mutation functional classification
Loss of Function (LOF)
Most LBR mutations are loss-of-function, leading to reduced sterol reductase activity or impaired nuclear envelope localization. Biallelic loss causes Greenberg dysplasia; heterozygous loss causes Pelger-Huët anomaly.
Gain of Function (GOF)
No gain-of-function mutations have been reported for LBR.
Dominant Negative (DN)
Some heterozygous missense mutations may exert a dominant-negative effect by interfering with wild-type LBR function in nuclear envelope assembly, but evidence is limited.
View complete mutation data：
Gene Ontology (GO)
| • nuclear envelope (GO:0005635) | • nuclear inner membrane (GO:0005637) |
| • C-14 sterol reductase activity (GO:0000249) | • cholesterol biosynthetic process (GO:0006695) |
| • nucleus organization (GO:0006997) | • nucleus (GO:0005634) |
Pathways
• Cholesterol biosynthesis (sterol reduction)
• Nuclear envelope assembly and disassembly
• Chromatin organization
Protein Summary
The lamin B receptor (LBR) is a 615-amino acid protein with an N-terminal nucleoplasmic domain that binds lamin B and chromatin, and a C-terminal domain with sterol reductase activity. It is anchored in the inner nuclear membrane. LBR plays a role in maintaining nuclear shape, heterochromatin anchoring, and cholesterol metabolism. Defects in LBR lead to nuclear abnormalities and skeletal dysplasia.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| LBR Knockout HEK293 Cell Line | EDJ-KQ2233 | Human | 3930 | Details Get a Quote |
| LBR Knockout HeLa Cell Line | EDJ-KQ21215 | Human | 3930 | Details Get a Quote |
| LBR Knockout A-549 Cell Line | EDJ-KQ22522 | Human | 3930 | Details Get a Quote |
| LBR Knockout HCT 116 Cell Line | EDJ-KQ22523 | Human | 3930 | Details Get a Quote |
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