Production of Monoclonal Antibodies to Small SARS Proteins Grant uri icon

abstract

  • Introduction: There are seven predicted SARS proteins in the 5 kb near the right terminus of the SARS virus genome that have little or no homology to known proteins (Marra, et al. Science, 2003). The terminal location of these genes in the genome suggests that the proteins they encode may be virulence factors, as the central portion of the SARS genome is conserved with other Coronavirus species. In linear viral genomes, essential replication genes are normally conserved in the central region and virulence factors are located near the termini of the genome (Upton, Slack, Hunter, Ehlers, and Roper J. Virol, 2003). Three of these SARS ORFs are very small (39-63 amino acids) and some have even been excluded from annotation by sequencing groups and are being disregarded because of their size. However the fact that viral genomes are usually very compact with little intergenic space, the conservation of these genes in SARS isolates (www .sarsresearch.ca), and the presence of upstream transcriptional regulatory sequences (Marra, et al. Science, 2003) support the hypothesis that these ORFs are functional in the virus life cycle. Furthermore, five of these proteins have significant hydrophobic regions that are predicted by at least one bioinformatics prediction program to be transmembrane spanning regions, defining a sequence that determines translocation across the ER membrane to produce either an integral membrane protein or a secreted protein. Both secreted and membrane proteins may be significant virulence factors inhibiting immune responses and causing the high mortality in SARS patients. Bioinformatics analysis suggests that some of these proteins possess motifs, which, if functional, would make excellent drug targets. Goals: I propose to 1) make monoclonal antibodies to these proteins of interest, 2) determine whether the proteins are made in virus-infected Vero cells, 3) determine where the proteins are localized (secreted into supernatants, ER/Golgi, virus particle, cytoplasmic membrane), 4) determine what interactions exist between viral proteins or virus/host protein interactions. This information should lead to a basic understanding of the biology of these proteins and yield hypotheses as to the functions of the proteins in the virus life cycle.

date/time interval

  • February 2004 - October 2004