Drug Discov Ther. 2021;15(4):189-196. (DOI: 10.5582/ddt.2021.01069)

Ectopic expression of Id1 or Id3 inhibits transcription of the GATA-4 gene in P19CL6 cells under differentiation condition

Yokura-Yamada Y, Araki M, Maeda M

Inhibitor of DNA binding (Id) is a dominant negative form of the E-box binding basic-helixloop- helix (bHLH) transcription factor since it is devoid of the basic region required for DNA binding and forms an inactive hetero dimer with bHLH proteins. The E-box sequence located in the promoter region of the GATA-binding protein 4 (GATA-4) gene is essential for transcriptional activation in P19CL6 cells. These cells differentiate into cardiomyocytes and start to express GATA- 4, which further triggers cardiac-specific gene expression. In this study, expression plasmids for Ids tagged with human influenza hemagglutinin (HA)-FLAG were constructed and introduced into P19CL6 cells. The stable clones expressing the recombinant Id proteins (Id1 or Id3) were isolated. The GATA-4 gene expression in these clones under differentiation condition in the presence of 1% dimethyl sulfoxide (DMSO) was repressed, with concomitant abolishment of the transcription of α-myosin heavy chain (α-MHC), which is a component of cardiac myofibrils. Thus, the increased expression of Id protein could affect GATA-4 gene expression and negatively regulate the differentiation of P19CL6 cells.

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