Gene Summary: This gene encodes a member of the transforming growth factor beta (TGFB) family of cytokines, which are multifunctional peptides that regulate proliferation, differentiation, adhesion, migration, and other functions in many cell types. Many cells have TGFB receptors, and the protein positively and negatively regulates many other growth factors. The secreted protein is cleaved into a latency-associated peptide (LAP) and a mature TGFB1 peptide, and is found in either a latent form composed of a TGFB1 homodimer, a LAP homodimer, and a latent TGFB1-binding protein, or in an active form composed of a TGFB1 homodimer. The mature peptide may also form heterodimers with other TGFB family members. TGFB1 gene is frequently upregulated in tumor cells, and mutations in TGFB1 gene result in Camurati-Engelmann disease.General information above from NCBI
Subunit structure: Homodimer; disulfide-linked, or heterodimer with TGFB2 (By similarity). Secreted and stored as a biologically inactive form in the extracellular matrix in a 290 kDa complex (large latent TGF-beta1 complex) containing the TGFB1 homodimer, the latency-associated peptide (LAP), and the latent TGFB1 binding protein-1 (LTBP1). The complex without LTBP1 is known as the'small latent TGF-beta1 complex'. Dissociation of the TGFB1 from LAP is required for growth factor activation and biological activity. Release of the large latent TGF-beta1 complex from the extracellular matrix is carried out by the matrix metalloproteinase MMP3 (By similarity). May interact with THSD4; this interaction may lead to sequestration by FBN1 microfibril assembly and attenuation of TGFB signaling. Interacts with the serine proteases, HTRA1 and HTRA3: the interaction with either inhibits TGFB1-mediated signaling. The HTRA protease activity is required for this inhibition (By similarity). Latency-associated peptide interacts with NREP; the interaction results in a decrease in TGFB1 autoinduction (By similarity). Interacts with CD109, DPT and ASPN.
Domain: The 'straitjacket' and 'arm' domains encircle the growth factor monomers and are fastened together by strong bonding between Lys-56 and Tyr-103/Tyr-104. Activation of TGF-beta1 requires the binding of integrin alpha-V to an RGD sequence in the prodomain and exertion of force on this domain, which is held in the extracellular matrix by latent TGF-beta binding proteins. The sheer physical force unfastens the straitjacket and releases the active growth factor dimer (By similarity).
Subcellular location: Secreted, extracellular space, extracellular matrix.
Tissue specificity: Highly expressed in bone. Abundantly expressed in articular cartilage and chondrocytes and is increased in osteoarthritis (OA). Co-localizes with ASPN in chondrocytes within OA lesions of articular cartilage.
Induction: Activated in vitro at pH below 3.5 and over 12.5.
The precursor is cleaved into mature TGF-beta-1 and LAP, which remains non-covalently linked to mature TGF-beta-1 rendering it inactive.
Involvement in disease: Camurati-Engelmann disease (CE) [MIM:131300]: Autosomal dominant disorder characterized by hyperostosis and sclerosis of the diaphyses of long bones. The disease typically presents in early childhood with pain, muscular weakness and waddling gait, and in some cases other features such as exophthalmos, facial paralysis, hearing difficulties and loss of vision. Note=The disease is caused by mutations affecting the gene represented in this entry.
Sequence similarity: Belongs to the TGF-beta family.
General information above from UniProt