Betaglycan has two independent domains required for high affinity TGF-beta binding: proteolytic cleavage separates the domains and inactivates the neutralizing activity of the soluble receptor.

ABSTRACT: Betaglycan is a coreceptor for members of the transforming growth factor beta (TGF-beta) superfamily. Mutagenesis has identified two ligand binding regions, one at the membrane-distal and the other at the membrane-proximal half of the betaglycan ectodomain. Here we show that partial plasmin digestion of soluble betaglycan produces two proteolysis-resistant fragments of 45 and 55 kDa, consistent with the predicted secondary structure, which indicates an intervening nonstructured linker region separating the highly structured N- and C-terminal domains. Amino terminal sequencing indicates that the 45 and 55 kDa fragments correspond, respectively, to the membrane-distal and -proximal regions. Plasmin treatment of membrane betaglycan results in the production of equivalent proteolysis-resistant

SUBMITTER: Mendoza V 

PROVIDER: S-EPMC2796082 | biostudies-literature | 2009 Dec

REPOSITORIES: biostudies-literature