First Author | Hoffmann A | Year | 2005 |
Journal | J Biol Chem | Volume | 280 |
Issue | 29 | Pages | 27271-83 |
PubMed ID | 15911626 | Mgi Jnum | J:100815 |
Mgi Id | MGI:3589693 | Doi | 10.1074/jbc.M503368200 |
Citation | Hoffmann A, et al. (2005) Transforming growth factor-beta-activated kinase-1 (TAK1), a MAP3K, interacts with Smad proteins and interferes with osteogenesis in murine mesenchymal progenitors. J Biol Chem 280(29):27271-83 |
abstractText | TAK1 (transforming growth factor-beta-activated kinase-1), a MAP3K with considerable sequence similarity to Raf-1 and MEKK-1, has been identified as a transforming growth factor-beta/bone morphogenetic protein (BMP)-activated cytosolic component of the MAPK pathways. In this investigation, the molecular interactions between TAK1 and Smad proteins were characterized as well as their influence on BMP-mediated mesenchymal cell differentiation along the osteogenic/chondrogenic pathway. In co-immunoprecipitations we found an interaction of TAK1 with all Smads tested, R-Smads Smads1-5, the co-Smad Smad4, and the inhibitory Smads (I-Smad6 and I-Smad7). Smad interaction with TAK1 takes place through their MH2 domain. This interaction is dependent on the presence of an active kinase domain in TAK1. TAK1 dramatically interferes with R-Smad transactivation in reporter assays and affects subcellular distribution of Smad proteins. Activated TAK1 also interferes with BMP-dependent osteogenic development in murine mesenchymal progenitor cells (C3H10T 1/2). A potential TAK1-mediated apoptosis process could be excluded for these cells. Both synergistic and interfering influences of TAK1 on BMP-mediated Smad-signaling have been reported previously. We suggest that TAK1 is a factor that is involved in the fine-tuning of BMP effects during osteogenic development. |