| The GST pulldown assay showed that HtrA 1 binds to a broad range of Tgfbeta family proteins , including Bmp 4 , Gdf 5 , Tgfbetas and activin . ^^^ HtrA 1 inhibited signaling by Bmp 4 , Bmp 2 , and Tgfbeta 1 in C2C12 cells , presumably by preventing receptor activation . ^^^ |