Viroporins are small virus-encoded ion channel proteins. Most viroporins are monovalent
selective cation channels, with few showing the ability to conduct divalent cations, like
calcium (Ca2+). Nevertheless, some viroporins are known to disrupt host cell Ca2+
homeostasis, which is critical for virus replication and pathogenesis. Rotavirus nonstructural
protein 4 (NSP4) is an endoplasmic reticulum transmembrane glycoprotein that has a
viroporin domain (VPD), and NSP4 viroporin activity elevates cytosolic Ca2+ in mammalian …