Stomach flu season is upon us, and if you or your kids have suffered through a bout of what doctors call “viral gastroenteritis”, rotavirus may well be the culprit: it is the leading cause of the illness in children. One of the virus’ secrets of success lies in how it handles calcium, namely, rotavirus spills calcium out of our organelles and uses it to build more viruses. Scientists know that rotavirus nonstructural protein 4 (NSP4) is responsible for upsetting the calcium applecart, but until now they weren’t sure what the protein’s structure was or how it moved calcium out of the endoplasmic reticulum.
In a study published in mBio this week, a group at the Baylor College of Medicine identifies the portion of NSP4 that inserts into the endoplasmic reticulum membrane. As it turns out, the structure has a lot in common with “viroporins” – viral pore-forming proteins that interfere with membranes. Mutant viruses with NSP4 genes that don’t work are unable to increase the concentration of calcium in the cytoplasm of human cells, proving the porin plays a key role in disrupting calcium concentrations and in replication of the virus.
In a study published in mBio this week, a group at the Baylor College of Medicine identifies the portion of NSP4 that inserts into the endoplasmic reticulum membrane. As it turns out, the structure has a lot in common with “viroporins” – viral pore-forming proteins that interfere with membranes. Mutant viruses with NSP4 genes that don’t work are unable to increase the concentration of calcium in the cytoplasm of human cells, proving the porin plays a key role in disrupting calcium concentrations and in replication of the virus.
