Drosophila Models Reveal NAT Complex Roles in Heart Development and Enable Functional Validation of Congenital Heart Disease Variants

N-terminal acetylation, catalyzed by N-terminal acetyltransferase (NAT) complexes, is one of the most prevalent protein modifications in eukaryotic cells, yet its role in heart development remains poorly understood. Here, we use <i>Drosophila</i> as an in vivo platform to investigate the functions of NAT complex components in cardiac development and congenital heart disease (CHD). Focusing on the NatA complex, we showed that cardiac-specific knockdown of each of its three subunits (<i>Naa15-16</i>, <i>vnc</i>, and <i>san</i>) led to developmental lethality, structural disorganization, fibrosis, and impaired cardiac function in <i>Drosophila</i>. Remarkably, human NAA16 completely rescued the cardiac defects in <i>Naa15-16</i> silenced <i>Drosophila</i>, whereas a CHD-associated variant (NAA16-R70C) failed to do so, providing direct functional evidence of its pathogenicity. Together, these findings suggest the NatA complex as a critical regulator of heart development and provide functional validation linking variants in NatA complex genes to CHD. Further studies in mammalian models will be required to provide additional supporting evidence.