Bovine rotavirus maturation is a calcium-dependent process

Cell biology of viruses that assemble along the biosynthetic pathway

“…17 For VP7 this would be consistent with earlier studies showing binding of radioactive calcium to isolated virus particles . 34 The haemagglutinin protein, VP4, is also a unique protein whose role in the assembly is far from clear . It is apparently made on free ribosomes, lacks a signal sequence and is not glycosylated ; it is, however, a relatively hydrophobic protein which possesses a conserved 17 amino acid hydrophobic stretch that shows homology to the putative fusion peptides of the El proteins of SFV and Sindbis virus .…”

Expression of Nonstructural Rotavirus Protein NSP4 Mimics Ca 2+ Homeostasis Changes Induced by Rotavirus Infection in Cultured Cells

“…At this point, the outer capsid proteins VP7 and VP4 are assembled onto the DLPs, resulting in the formation of triple-layered particles within the ER lumen, the main Ca 2ϩ store of the cell (2,4,15,25). Depletion of calcium stored in the ER by different experimental maneuvers causes an abnormal accumulation of membraneenveloped intermediates, which are not infectious (26,33,38,39).…”

HT-29 cells: a new substrate for rotavirus growth

“…On the contrary, enteric features where observed when calcium, required for "double-shell" and infectivity stabilization [36], was added to the medium containing either FCS or TPB. It is well known that rotavirus maturation is a calcium-dependent process: in absence of calcium, virus yield is decreased and viral particles are found to be exclusively "single-shelled" [33,34].…”