Regulation of the Bioavailability of TGF-ß and TGF-ß-Related Proteins.

ABSTRACT

The bioavailability of members of the transforming growth factor ß (TGF-ß) family is controlled by a number of mechanisms. Bona fide TGF-ß is sequestered into the matrix in a latent state and must be activated before it can bind to its receptors. Here, we review the molecules and mechanisms that regulate the bioavailability of TGF-ß and compare these mechanisms with those used to regulate other TGF-ß family members. We also assess the physiological significance of various latent TGF-ß activators, as well as other extracellular modulators of TGF-ß family signaling, by examining the available in vivo data from knockout mouse models and other biological systems.