Plays a role in cellular signaling via Rho-related GTP-binding proteins and activation of transcription factor SRF. Targets TJP1 to cell junctions (By similarity). In cortical neurons, may play a role in glutaminergic signal transduction through interaction with the NMDA receptor subunit GRIN1 (By similarity). Interacts with DSP, MPRIP and TJP1/ZO1. Interaction with MPRIP inhibits the activation of transcription factor SRF. Interacts with GRIN1. Interacts with DYNLL1 (By similarity). Detected predominantly at the intercalated disk in cardiomyocytes, and at low levels on sarcomeric Z disks. Colocalizes with F-actin. Colocalizes with cortical actin. Detected in heart myocardium and lung. Detected in embryonic vasculature at 8 dpc. Detected in endocardium and the primitive ventricle at 9 dpc. First detected in myocardium at 11.5 dpc. Highly expressed in heart and lung at 15.5 dpc and in neonates, wherease expression in vasculature is no longer detectable. Belongs to the MYZAP family.