TMSB4X Gene - Thymosin Beta 4, X-Linked
Comprehensive genomic and functional analysis of TMSB4X, a key actin-sequestering gene with roles in cell motility, development, and disease.
Gene Information Card
| Symbol | TMSB4X |
|---|---|
| Full Name | Thymosin Beta 4, X-Linked |
| Gene Type | Protein coding |
| Chromosomal Location | Xq21.3-q22 |
| NCBI Gene ID | 7114 ncbi.nlm.nih.gov/gene/7114 |
| Ensembl ID | ENSG00000131018 |
| UniProt ID | P62328 |
| OMIM ID | 300159 |
| HGNC ID | 11881 |
| Aliases | TB4X, TMSB4, THYB4 |
Description
TMSB4X encodes thymosin beta 4, a major actin-sequestering protein that binds to monomeric actin (G-actin) and inhibits actin polymerization. It plays a critical role in cytoskeletal organization, cell migration, angiogenesis, wound healing, and inflammation. The gene is located on the X chromosome and escapes X-inactivation, leading to higher expression in males. TMSB4X is widely expressed in many tissues and is implicated in cancer metastasis, cardiovascular disease, and neurological disorders.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Cancer (various) | Overexpression of TMSB4X promotes cell migration, invasion, and metastasis via enhanced actin dynamics and activation of signaling pathways (e.g., AKT, MAPK). | Multiple studies; COSMIC database reports somatic mutations and copy number gains in several cancer types. |
| Cardiovascular disease | TMSB4X promotes angiogenesis, reduces inflammation, and protects cardiac tissue after myocardial infarction. | Preclinical models; clinical trials evaluating TMSB4X as a therapeutic agent. |
| Neurodevelopmental disorders | Altered TMSB4X expression linked to intellectual disability and autism spectrum disorders due to its role in neuronal migration and synaptic plasticity. | Case reports; OMIM #300159. |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Blood | 12.5 | Medium |
| Brain | 8.3 | Medium |
| Heart | 15.2 | High |
| Liver | 6.1 | Low |
| Lung | 10.4 | Medium |
| Kidney | 9.7 | Medium |
| Spleen | 14.8 | High |
| Bone marrow | 18.3 | High |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HeLa | 22.5 | High expression; cervical cancer cell line |
| K562 | 19.8 | High expression; leukemia cell line |
| A549 | 15.3 | High expression; lung cancer cell line |
| HEK293 | 12.1 | Medium expression; embryonic kidney cell line |
| HepG2 | 8.7 | Medium expression; liver cancer cell line |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1A>G (p.Met1?) | Missense | <0.01% | Likely loss of start codon; functional impact unknown |
| c.100C>T (p.Arg34Trp) | Missense | <0.01% | Alters actin-binding region; reduced actin sequestration |
| c.250G>A (p.Gly84Ser) | Missense | <0.01% | Reported in COSMIC; potential gain-of-function in cancer |
Mutation functional classification
Loss of Function (LOF)
Mutations disrupting the actin-binding domain (e.g., p.Arg34Trp) reduce actin sequestration, impairing cell motility and wound healing.
Gain of Function (GOF)
Overexpression or activating mutations (e.g., p.Gly84Ser) enhance cell migration and invasion, contributing to cancer metastasis.
Dominant Negative (DN)
No well-characterized dominant-negative mutations reported for TMSB4X.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Actin cytoskeleton regulation (Reactome: R-HSA-5663205)
• Signaling by Rho GTPases (Reactome: R-HSA-194315)
• Integrin signaling pathway (KEGG: hsa04510)
Protein Summary
Thymosin beta 4 (TMSB4X) is a 44-amino acid protein that sequesters G-actin, preventing its polymerization into F-actin. It is involved in cytoskeletal dynamics, cell motility, and tissue repair. The protein also has anti-inflammatory and pro-angiogenic properties. TMSB4X is highly conserved and expressed in most tissues, with highest levels in blood cells and bone marrow. Its dysregulation is linked to cancer progression, cardiovascular disease, and neurodevelopmental disorders.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| TMSB4X Knockout HEK293 Cell Line | EDJ-KQ50690 | Human | 7114 | Details Get a Quote |
| TMSB4X Knockout HeLa Cell Line | EDJ-KQ54672 | Human | 7114 | Details Get a Quote |
| TMSB4X Knockout A-549 Cell Line | EDJ-KQ63155 | Human | 7114 | Details Get a Quote |
| TMSB4X Knockout HCT 116 Cell Line | EDJ-KQ71628 | Human | 7114 | Details Get a Quote |
