FLNB Gene: Filamin B
A comprehensive guide to FLNB, its function, associated diseases, and clinical significance.
Gene Information Card
| Symbol | FLNB |
|---|---|
| Full Name | Filamin B |
| Gene Type | Protein coding |
| Chromosomal Location | 3p14.3 |
| NCBI Gene ID | 2317 ncbi.nlm.nih.gov/gene/2317 |
| Ensembl ID | ENSG00000136068 |
| UniProt ID | O75369 |
| OMIM ID | 603381 |
| HGNC ID | 3755 |
| Aliases | ABP-278, ABP-280, FH1, FLN-B, FLN1L, SCT, TAP |
Description
The FLNB gene encodes filamin B, an actin-binding protein that crosslinks actin filaments and links them to membrane glycoproteins. It plays a crucial role in cytoskeletal organization, cell motility, and signal transduction. Mutations in FLNB are associated with a spectrum of skeletal disorders, including Larsen syndrome, atelosteogenesis types I and III, and boomerang dysplasia.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Larsen syndrome | Dominant-negative mutations in FLNB disrupt actin cytoskeleton, leading to skeletal abnormalities | OMIM #150250 |
| Atelosteogenesis type I | Loss-of-function or dominant-negative mutations impair bone development | OMIM #108720 |
| Atelosteogenesis type III | Mutations affecting filamin B function cause severe skeletal dysplasia | OMIM #108721 |
| Boomerang dysplasia | Severe dominant-negative mutations in FLNB result in characteristic bone shapes | OMIM #112310 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Skeletal muscle | 31.2 | High |
| Heart | 22.5 | High |
| Lung | 12.8 | Medium |
| Kidney | 10.1 | Medium |
| Liver | 5.3 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HeLa | 15.0 | Cervical adenocarcinoma |
| A549 | 12.5 | Lung carcinoma |
| HEK 293 | 18.2 | Embryonic kidney |
| K562 | 8.9 | Leukemia |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.502G>A (p.Gly168Arg) | Missense | Rare | Dominant-negative; associated with Larsen syndrome |
| c.740C>T (p.Pro247Leu) | Missense | Rare | Dominant-negative; associated with atelosteogenesis type I |
| c.1960C>T (p.Arg654Trp) | Missense | Rare | Dominant-negative; associated with boomerang dysplasia |
| c.471+1G>A | Splice site | Rare | Loss of function; associated with atelosteogenesis type III |
Mutation functional classification
Loss of Function (LOF)
Rare; splice site mutations leading to truncated protein and severe skeletal dysplasia.
Gain of Function (GOF)
Not reported for FLNB.
Dominant Negative (DN)
Common mechanism; missense mutations in actin-binding domain disrupt filamin dimerization and actin crosslinking.
View complete mutation data：
Gene Ontology (GO)
| • actin binding | • actin filament binding |
| • cytoskeletal protein binding | • structural constituent of cytoskeleton |
| • cell adhesion | • cell migration |
| • signal transduction |
Pathways
• Actin cytoskeleton regulation
• Focal adhesion
• ECM-receptor interaction
Protein Summary
Filamin B is a 278 kDa actin-binding protein that forms homodimers and crosslinks actin filaments into orthogonal networks. It also interacts with integrins and signaling molecules, contributing to cell adhesion and migration. The protein is highly expressed in skeletal muscle and heart.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| FLNB Knockout HEK293 Cell Line | EDJ-KQ666 | Human | 2317 | Details Get a Quote |
| FLNB Knockout A-549 Cell Line | EDJ-KQ19189 | Human | 2317 | Details Get a Quote |
| FLNB Knockout HCT 116 Cell Line | EDJ-KQ19190 | Human | 2317 | Details Get a Quote |
| FLNB Knockout HeLa Cell Line | EDJ-KQ19191 | Human | 2317 | Details Get a Quote |
