Porcine Circovirus Type 2 Induces ORF3-Independent Mitochondrial Apoptosis via PERK Activation and Elevation of Cytosolic Calcium

Abstract

PCV2 encodes protein ORF3, a putative protein with proapoptotic activity. Our early studies showed that PCV2 infection triggers ER stress via selective activation of the PERK pathway, a branch of the ER stress pathways, in permissive cells for enhanced replication and infection increased cytosolic Ca 2+ and ROS levels. Here we clearly show that PCV2 infection or Cap expression induces ORF3-independent apoptosis via increased cytosolic and mitochondrial Ca 2+ levels and cellular ROS levels as a result of activation of the PERK pathway.