LTBP4: Latent Transforming Growth Factor Beta Binding Protein 4
Key regulator of TGF-β bioavailability and extracellular matrix assembly
Gene Information Card
| Symbol | LTBP4 |
|---|---|
| Full Name | Latent Transforming Growth Factor Beta Binding Protein 4 |
| Gene Type | protein-coding |
| Chromosomal Location | 19q13.2 |
| NCBI Gene ID | 8425 ncbi.nlm.nih.gov/gene/8425 |
| Ensembl ID | ENSG00000105699 |
| UniProt ID | Q8N2S1 |
| OMIM ID | 604710 |
| HGNC ID | 6717 |
| Aliases | LTBP-4, LTBP4L, LTBP4S |
Description
LTBP4 encodes a member of the latent transforming growth factor beta (TGF-β) binding protein family. The protein binds TGF-β in a latent complex and targets it to the extracellular matrix, regulating TGF-β bioavailability. LTBP4 is also a structural component of microfibrils, interacting with fibrillin-1. Mutations in LTBP4 are associated with autosomal recessive cutis laxa type IC and may contribute to emphysema and cancer susceptibility.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Cutis laxa, autosomal recessive, type IC | Loss-of-function mutations impair TGF-β sequestration, leading to elastic fiber fragmentation and skin laxity | OMIM #613177 |
| Emphysema, susceptibility to | Reduced LTBP4 expression in lung tissue alters TGF-β signaling and alveolar integrity | PMID: 26073755 |
| Colorectal cancer | Somatic mutations and altered expression may dysregulate TGF-β-mediated tumor suppression | COSMIC |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Lung | 12.3 | Medium |
| Heart | 8.7 | Medium |
| Placenta | 6.5 | Low |
| Skeletal muscle | 5.2 | Low |
| Kidney | 4.1 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| A549 (lung carcinoma) | 15.2 | High expression |
| HepG2 (hepatocellular carcinoma) | 3.8 | Low expression |
| MCF7 (breast adenocarcinoma) | 2.1 | Very low |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1399C>T (p.Arg467*) | Nonsense | Rare | Loss of function; associated with cutis laxa |
| c.2023G>A (p.Gly675Arg) | Missense | Rare | Impaired TGF-β binding; cutis laxa |
| c.2962C>T (p.Arg988Trp) | Missense | 0.01% (gnomAD) | Unknown significance |
Mutation functional classification
Loss of Function (LOF)
Nonsense and frameshift mutations that truncate the protein, reducing TGF-β sequestration and microfibril integrity.
Gain of Function (GOF)
Not described for LTBP4.
Dominant Negative (DN)
Missense mutations in the TGF-β binding domain may interfere with latent complex formation.
View complete mutation data：
Gene Ontology (GO)
| • extracellular matrix structural constituent | • TGF-beta binding |
| • protein binding | • extracellular space |
| • microfibril | • regulation of TGF-beta receptor signaling pathway |
Pathways
• TGF-beta signaling pathway (KEGG hsa04350)
• Extracellular matrix organization (Reactome R-HSA-1474244)
Protein Summary
LTBP4 is a 162 kDa secreted glycoprotein that forms part of the large latent TGF-β complex. It contains multiple EGF-like domains and a hybrid motif that mediates covalent crosslinking to the extracellular matrix. The protein is essential for proper elastic fiber assembly and for controlling TGF-β activation in tissues such as lung and skin.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| LTBP4 Knockout HEK293 Cell Line | EDJ-KQ6235 | Human | 8425 | Details Get a Quote |
| LTBP4 Knockout A-549 Cell Line | EDJ-KQ30081 | Human | 8425 | Details Get a Quote |
| LTBP4 Knockout HCT 116 Cell Line | EDJ-KQ30082 | Human | 8425 | Details Get a Quote |
| LTBP4 Knockout HeLa Cell Line | EDJ-KQ28779 | Human | 8425 | Details Get a Quote |
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