GENETIC-CHARACTERIZATION OF THE ROTAVIRUS NONSTRUCTURAL PROTEIN, NSP4

The rotavirus nonstructural protein NSP4 plays a role in viral assembl y by acting as an intracellular receptor for single-shelled particles and assisting in the translocation of these particles across the endop lasmic reticulum. Recently, NSP4 has been implicated in rotavirus viru lence and is thought to act as an enterotoxin which triggers chloride secretion by a calcium-dependent signal transduction pathway. Limited sequence analysis of NSP4 shows a well-conserved protein. To define th e extent of sequence variation in the gene coding for NSP4, we have se quenced this gene from nine human rotavirus strains. These data and th e analysis of additional human strains and various animal rotaviruses (bovine, simian, equine, and porcine) by Northern blot hybridization s uggested that three NSP4 genotypes were present among rotavirus strain s, A correlation between NSP4 genotype and VP6 subgroup was also impli ed. Two different NSP4 genes (which encoded distinct types of NSP4 pro teins) were found among standard human rotaviruses and in strains circ ulating in the local community and these showed homology to cognate ge nes in some animal strains. (C) 1997 Academic Press.