Novel 150- and 180-kDa glycoproteins that bind transforming growth factor (TGF)-beta 1 but not TGF-beta 2 are present in several cell lines.
We identified transforming growth factor-beta (TGF-beta)-binding proteins which are distinct from previously described TGF-beta receptors or TGF-beta-binding proteins. These TGF-beta-binding proteins migrate as 150- and 180-kDa 125I-TGF-beta 1 affinity-labeled complexes which are consistently co-expressed in A549, Mv1Lu, MG-63, and BS-C-1 cells. They differ from the types I, II, and III TGF-beta receptors in their electrophoretic mobilities, their lack of binding to TGF-beta 2, and their failure to undergo the marked down-regulation seen with types I, II, and III receptors following a 16-h incubation with TGF-beta 1. The 150- and 180-kDa TGF-beta-binding proteins also are distinct from the recently described disulfide-linked TGF-beta 1-binding proteins which are present in rat glomeruli. In contrast to the glomerular TGF-beta 1-binding proteins, the electrophoretic mobilities of the 150- and 180-kDa binding proteins are unchanged following reduction. In addition, the 150- and 180-kDa TGF-beta-binding proteins are present in the detergent-rich phase during Triton X-114 phase separation, whereas the glomerular TGF-beta-binding proteins partition exclusively into the detergent-poor phase.
MacKay
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Kidney Disease Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892.
Danielpour
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D000345:Affinity Labels; D000818:Animals; D002460:Cell Line; D015536:Down-Regulation; D004591:Electrophoresis, Polyacrylamide Gel; D006023:Glycoproteins / Q000378:metabolism*; D008970:Molecular Weight; D010641:Phenotype; D011956:Receptors, Cell Surface / Q000378:metabolism; D018125:Receptors, Transforming Growth Factor beta; D013379:Substrate Specificity; D013552:Swine; D016212:Transforming Growth Factor beta / Q000378:metabolism*
D000345:Affinity Labels; D006023:Glycoproteins; D011956:Receptors, Cell Surface; D018125:Receptors, Transforming Growth Factor beta; D016212:Transforming Growth Factor beta