Transforming growth factor β (TGF-β) signals through a heteromeric complex of type I and type II transmembrane serine-threonine kinases. Recent evidence suggests that the immunophilin FKBP12 modulates the activity of the type I receptor, based on data that immunosuppressive drugs that disrupt FKBP12 binding to the type I receptor enhance TGF-β signaling in mink lung epithelial cells, and overexpression of FKBP12 inhibits type I receptor phosphorylation by the type II receptor. To determine the physiological relevance of the FKBP12-TGF-β receptor I interaction, we investigated whether disruption of this interaction affects TGF-β-signaling in primary mouse embryo fibroblasts and thymocytes. We found that the addition of excess drugs had no effect on either TGF-β-mediated transcriptional responses or growth inhibition. Dose-response curves for TGF-β-mediated signaling in primary fibroblasts and thymocytes isolated from either wild-type or FKBP12- deficient mice were identical. Taken together, our results indicate that FKBP12 does not play a unique physiological role in TGF-β signaling in primary fibroblasts and thymocytes.
|Original language||English (US)|
|Number of pages||6|
|Journal||Cell Growth and Differentiation|
|State||Published - 1998|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology