Thymosin beta-4 X-linked (TMSB4X)

Thymosin beta-4 X-linked (TMSB4X) is a small peptide encoded by the TMSB4X gene and recognized as a key actin-sequestering protein in mammalian cells[2][3]. It binds monomeric (G-) actin, preventing its polymerization and thus regulating cell motility, morphology, and cytoskeleton dynamics[1][3]. TMSB4X exerts additional biological activities via its fragments, including promotion of cell migration, proliferation, differentiation, angiogenesis, anti-inflammatory, antifibrotic, and anti-apoptotic effects[2][4]. Hemoregulatory peptide AcSDKP, a fragment of TMSB4X, inhibits entry of hematopoietic stem cells into DNA synthesis (S-phase), impacting stem cell differentiation[2]. TMSB4X is implicated as a therapeutic target in cancer, tissue repair, inflammation, cardiovascular disease, and fibrosis, with ongoing research and some clinical development focused on recombinant or synthetic thymosin beta-4 (timbetasin)[3][4].

Other names

Thymosin beta-4Hemoregulatory peptide AcSDKPTMSB4XTB4XTHYB4TMSB4T beta-4AcSDKPFxAc-Ser-Asp-Lys-ProN-acetyl-SDKPSeraspenideFXPTMB4prothymosin beta-4timbetasin (INN)

Drugs or peptides that mimic TMSB4X: promote cell migration, angiogenesis, anti-inflammation, or tissue regeneration Antagonists (theoretical): inhibit actin polymerization by sequestering G-actin, alter cytoskeletal dynamics