Collectively, our results identify claudin-1 as a novel internalization factor for porcine enteric coronaviruses, playing a critical role in facilitating infection within the digestive tract, and highlight its potential as a target for future clinical interventions.<h4>Importance</h4>We observed a downregulation in the expression of the majority of tight junction proteins in intestinal tissues infected with transmissible gastroenteritis virus (TGEV). This evidence concerns the gene CLDN1 and infection.