BMP signaling regulates Nkx2-5 activity during cardiomyogenesis

Nkx2-5 regulates the transcription of muscle-specific genes during cardiomy ogenesis. Nkx2-5 expression can induce cardiomyogenesis in aggregated P19 c ells but not in monolayer cultures. In order to investigate the mechanism b y which cellular aggregation regulates Nkx2-5 function, we examined the rol e of bone morphogenetic protein 4 (BMP4). We showed that the expression of the BMP inhibitor, noggin, was sufficient to inhibit the induction of cardi omyogenesis by Nkx2-5 during cellular aggregation. Furthermore, soluble BMP 4 could activate Nkx2-5 function in monolayer cultures, resulting in the fo rmation of cardiomyocytes. Therefore, BMP signaling is necessary and suffic ient for the regulation of Nkx2-5 activity during cardiomyogenesis in P19 c ells. (C) 2001 Published by Elsevier Science B.V. on behalf of the Federati on of European Biochemical Societies.