Transcriptional cofactor that restricts GATA6 function by inhibiting DNA-binding, resulting in repression of GATA6 transcriptional activation of downstream target genes. Represses GATA6-mediated trans activation of lung- and cardiac tissue-specific promoters. Inhibits DNA-binding by GATA4 and GATA1 to the cTNC promoter. Plays a critical role in the development of cardiac hypertrophy via activation of calcineurin/nuclear factor of activated T-cells signaling pathway (By similarity). Interacts with beta-dystroglycan. Interacts with GATA1, GATA4 and GATA6 (By similarity). May shuttle between the cytoplasm and the nucleus. Highly expressed in both skeletal muscle and cardiac muscle. The LIM zinc-binding domains and the Cys-rich region mediate interaction with GATA6.