Abstract: Objective To investigate the regulatory mechanism of regulator of calcineurin 1 (RCAN1), which is associated with congenital heart disease and has a tissue-specific expression pattern. Methods The transcription factor binding sites were predicted and compared in promoter of RCAN1. The site directed mutation and luciferase assay were used to detect the activity of the binding site. Then the transcriptional regulation of RCAN1 by Sp1 was evaluated by real-time quantitative PCR under physiological condition (control group) or Sp1 inhibitor (experimental group). Results The Sp1 binding site-138GCCCGCCGCC-129 was predicated and identified. The RCAN1-1 mRNA was more decreased in experimental group than the control group (P＜0.001). There was no significant difference in RCAN1-4 mRNA between the two groups. Conclusions Sp1 specifically regulates the transcription of RCAN1-1 isoform, which demonstrates that Sp1 is a potential targete molecule for genetic testing and clinical intervention for congenital heart disease.

Key words: congenital heart disease, Sp1, RCAN1, transcription, gene