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transforming growth factor beta-1; TGF-beta-1; contains: latency-associated peptide; LAP (TGFB1 TGFB)

Function: - multifunctional protein - controls proliferation, differentiation & other functions in many cell types - many cells synthesize TGFB1 & have specific receptors for it - positively & negatively regulates many other growth factors - role in bone remodeling as it is a potent stimulator of osteoblastic bone formation, causing chemotaxis, proliferation & differentiation in committed osteoblasts - the precursor is cleaved into mature TGF-beta-1 & latency-associated peptide (LAP_, which remains non-covalently linked to mature TGF-beta-1 rendering it inactive - the inactive form consists of a TGFB1 homodimer non-covalently linked to a latency-associated peptide (LAP) - later disulfide-linked to a latent TGFB1-binding protein anchored to the extracellular matrix - the active form is a homodimer of mature TGFB1, disulfide-linked - heterodimers of TGFB1/TGFB2 have been found in bone - interacts with CD109 & DPT - interacts with ASPN - activated in vitro at pH below 3.5 & over 12.5 Structure: - homodimer, disulfide-linked - glycosylated - the 'straitjacket' & 'arm' domains encircle the growth factor monomers & are fastened together by strong bonding between Lys-56 & Tyr-103/Tyr-104 - activation of TGF-beta1 requires the binding of integrin alpha-V to an RGD sequence in the prodomain & 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 & releases the active growth factor dimer (putative) - belongs to the TGF-beta family Compartment: - secreted, extracellular space, extracellular matrix Expression: - highly expressed in bone - abundantly expressed in articular cartilage & chondrocytes Polymorphism: - in post-menopausal Japanese women, the frequency of Leu-10 is higher in subjects with osteoporosis than in controls Pathology: - expression is increased in osteoarthritis (OA) - co-localizes with ASPN in chondrocytes within OA lesions of articular cartilage - defects in TGFB1 are the cause of Camurati-Engelmann disease

Related

TGF-beta 1 gene

General

glycoprotein transforming growth factor [TGF]-beta

Properties

CONFIGURATION: dimer SIZE: entity length = 390 aa MW = 44 kD COMPARTMENT: extracellular compartment MOTIF: signal sequence {1-29} Straightjacket domain {30-74} MOTIF: cysteine residue {C33} MODIFICATION: cysteine residue {C1359} Arm domain {75-271} MOTIF: N-glycosylation site {N82} N-glycosylation site {N136} N-glycosylation site {N176} cysteine residue {C223} MODIFICATION: cysteine residue {C225} cysteine residue {C225} MODIFICATION: cysteine residue {C223} Cell attachment site {244-246} cysteine residue {C285} MODIFICATION: cysteine residue {C294} cysteine residue {C293} MODIFICATION: cysteine residue {C356} cysteine residue {C294} MODIFICATION: cysteine residue {C285} cysteine residue {C322} MODIFICATION: cysteine residue {C387} cysteine residue {C326} MODIFICATION: cysteine residue {C389} cysteine residue {C355} MODIFICATION: cysteine residue {C-INTERCHAIN} cysteine residue {C356} MODIFICATION: cysteine residue {C293} cysteine residue {C387} MODIFICATION: cysteine residue {C322} cysteine residue {C389} MODIFICATION: cysteine residue {C326} SECRETED-BY: platelet macrophage monocyte T-cell endothelial cell fibroblast

Database Correlations

OMIM correlations MORBIDMAP 190180 UniProt P01137 PFAM correlations Entrez Gene 7040 Kegg hsa:7040

References

  1. Sporn MB, Roberts AB. Interactions of retinoids and transforming growth factor-beta in regulation of cell differentiation and proliferation. Mol Endocrinol. 1991 Jan;5(1):3-7. Review. PMID: 2017191
  2. Entrez Gene :accession 7040
  3. UniProt :accession P01137
  4. GeneReviews http://www.ncbi.nlm.nih.gov/sites/genetests/lab/gene/TGFB1
  5. Wikipedia; Note: TGF beta-1 entry http://en.wikipedia.org/wiki/TGF_beta_1