Abstract: AIM: To identify the function ORF(open reading frame)U41 of human herpesvirus 7(HHV-7).METHODS: Immunofluorescent detection was used to show the localization of the U41 protein in cells.The expression kinetics of the U41 gene in the presence of cycloheximide(CHX)and phosphomoformic acid(PFA),which are inhibitors of protein synthesis and of viral DNA synthesis respectively,was detected with RT-PCR.DNA binding assay was used to detect the single and double DNA strands binding ability of U41 protein.RESULTS: The U41 protein was expressed as an early protein in the HHV-7 infected cells and localized only in the nuclei of infected cells.The U41 protein was able to bind to a single-strand DNA cellulose column but not to double-strand DNA cellulose column from DNA binding assay.CONCLUSION: The major function of U41 may be to keepthe DNA template in the optimal conformation for DNA elongation and for viral DNA synthesis.

Key words: herpesvirus, open reading frame, immunofluorescence, cycloheximide, phosphomoformic acid