A HERPESVIRUS SAIMIRI PROTEIN REQUIRED FOR INTERLEUKIN-2 INDEPENDENCEIS ASSOCIATED WITH MEMBRANES OF TRANSFORMED T-CELLS

A region of the herpesvirus saimiri genome encoding an mRNA with two o pen reading frames (ORFs) has been identified to be essential for tran sformation of T cells. Deletion of either ORF resulted in the loss of transforming ability. ORF-1 has been shown to code for a collagen-like oncoprotein. This study shows for the first time that the bicistronic mRNA can translate a 32-kDa protein from ORF-2. Polyclonal serum to O RF-2 was generated by using a glutathione fusion protein. Using this a ntiserum, ORF-2 was localized in cell membranes and is expressed on th e outer cell membrane. The half-life of this membrane protein was foun d to be about 5.5 h. Limited sequence similarity was found between ORF -2 and interleukin-11; however, no secretion of ORF-2 protein was dete cted in supernatants from transformed cells. Further studies are requi red to investigate the potential interaction with the interleukin-11 r eceptor.