| Further , we show that Mef2c is a direct target of Foxh 1 , which physically and functionally interacts with Nkx 2 5 to mediate strong Smad dependent activation of a TGFbeta response element in the Mef2c gene . ^^^ Thus , Foxh 1 and Nkx 2 5 functionally interact and are essential for development of the AHF and its derivatives , the RV and OFT , in response to TGFbeta like signals . . ^^^ |