General Description
The gene TGF-β3 (transforming growth factor β 3) is mapped to human chromosome 14q24.3. The three mammalian isoforms of TGF-β, TGF-β1, β2, β3 elicit similar biological responses. TGF-β proteins are made as precursor molecules which are cut to generate a mature carboxy-terminal region of 110-140 amino acids. They are secreted predominantly as latent complexes which are stored at the cell surface and in the extracellular matrix. The release of biologically active TGF-β isoform from a latent complex involves proteolytic processing of the complex and/or induction of conformational changes by proteins such as thrombospondin-1. Recombinant TGF-β3 is a 25.0kDa protein composed of two identical 112 amino acid polypeptide chains linked by a single disulfide bond.
Biochem/physiol Actions
The three mammalian isoforms of TGF-β (transforming growth factor β), TGF-β1, β2, β3, are multifunctional cytokines that regulate cell proliferation, growth, differentiation and motility as well as synthesis and deposition of the extracellular matrix. They are involved in various physiological processes including embryogenesis, tissue remodeling and wound healing. TGF-β3 is the predominant TGF-β in the testis and controls the blood-testis barrier activity. Polymorphisms in this gene might be associated with male infertility. Heterozygous mutation in the gene at position Arg300 might be associated with increased TGF-β signaling, leading to a disorder with phenotypic overlap with Marfan syndrome and Loeys-Dietz syndrome. TGF-β3 is involved in the mesenchymal stem cells (MSCs)-mediated inhibition of fibroblast proliferation and decreases skin fibrosis.
