CHARACTERIZATION OF THE PRODUCTS OF THE U(L)43 GENE OF HERPES-SIMPLEXVIRUS-1 - POTENTIAL IMPLICATIONS FOR REGULATION OF GENE-EXPRESSION BYANTISENSE TRANSCRIPTION

The products, RNA or proteins, of the herpes simplex virus 1 open read ing frame U(L)43 have not been previously identified. The expression o f an open reading frame antisense to U(L)43, U(L)43.5 (P. L. Ward, D. E. Earlier, and B. Roizman, J. Virol. 70:2684-2690, 1996), has been re ported. We report the existence of a transcript corresponding to the d omain of the U(L)43 open reading frame extending approximately 30 bp f rom the predicted TATA. box to the predicted polyadenylation signal. T he RNA of the U(L)43 open reading frame accumulates to higher levels i n the presence of phosphonoacetic acid, an inhibitor of viral DNA synt hesis, than in its absence, whereas the U(L)43.5 transcript accumulate s in larger amounts in the absence of phosphonoacetic acid. The open r eading frame tagged with a sequence encoding a 20-amino-acid epitope y ielded a protein with an apparent M(r), of 32,000, i.e., considerably lower than that predicted from the size of the open reading frame. The discovery of a pair of antisense genes expressed during productive in fection raises the possibilities that additional antisense genes exist and that the antisense arrangement provides still another mechanism f or regulation of gene expression.