First Author | Ueyama T | Year | 2003 |
Journal | Mol Cell Biol | Volume | 23 |
Issue | 24 | Pages | 9222-32 |
PubMed ID | 14645532 | Mgi Jnum | J:86864 |
Mgi Id | MGI:2682181 | Doi | 10.1128/MCB.23.24.9222-9232.2003 |
Citation | Ueyama T, et al. (2003) Myocardin expression is regulated by Nkx2.5, and its function is required for cardiomyogenesis. Mol Cell Biol 23(24):9222-32 |
abstractText | Nkx2.5 (also known as Csx) is an evolutionarily conserved cardiac transcription factor of the homeobox gene family. Nkx2.5 is required for early heart development, since Nkx2.5-null mice die before completion of cardiac looping. To identify genes regulated by Nkx2.5 in the developing heart, we performed subtractive hybridization by using RNA isolated from wild-type and Nkx2.5-null hearts at embryonic day 8.5. We isolated a mouse cDNA encoding myocardin A, which is an alternative spliced isoform of myocardin and the most abundant isoform in the heart from embryo to adult. The expression of myocardin A and myocardin was markedly downregulated in Nkx2.5-null mouse hearts. Transient-cotransfection analysis showed that Nkx2.5 transactivates the myocardin promoter. Inhibition of myocardin function in the teratocarcinoma cell line P19CL6 prevented differentiation into cardiac myocytes after dimethyl sulfoxide treatment. Myocardin A transactivated the promoter of the atrial natriuretic factor gene through the serum response element, which was augmented by bone morphogenetic protein 2 and transforming growth factor beta-activated kinase 1. These results suggest that myocardin expression is regulated by Nkx2.5 and that its function is required for cardiomyogenesis. |