The role of pp38 in regulation of Marek's disease virus bi-directional promoter between pp38 and 1.8-kb mRNA. Academic Article uri icon

abstract

  • Marek's disease virus (MDV) contains a bi-directional promoters located between pp38 gene and 1.8-kb mRNA in the long inverted repeat region of the viral genome. The involvement of pp38 gene in up-regulating the activity of these promoters was analyzed by transient expression of chloramphenicol acetyltransferase (CAT) reporter gene. Two CAT reporter plasmids, pP(pp38)-CAT and pP(1.8-kb)-CAT, were constructed to express CAT under the control of the bi-directional promoter in both orientations. These plasmids were transfected into chicken embryonic fibroblast (CEF), infected with rMd5 and pp38 deleted rMd5 (rMd5/Deltapp38), respectively. No CAT activity was detected in uninfected CEF as expected. CAT activities in rMd5/Deltapp38 virus infected CEF (rMd5/Deltapp38-CEF) were 3.5-fold lower using pP(pp38)-CAT and 12-fold lower using pP(1.8-kb)-CAT than those of the parental rMd5 infected CEF (rMd5-CEF). The significantly lower promoter activity in the pp38 deletion virus suggests that pp38 can regulate the activity of the bi-directional promoters, especially in the direction of 1.8-kb mRNA family. Co-transfection of pp38-expressing plasmid (pcDNA-pp38) into rMd5/Deltapp38-CEF significantly increased the activity of the bi-directional promoters using either pP(pp38)-CAT or pP(1.8-kb)-CAT. DNA mobility shift assay showed a binding of the 73-bp sequence of the bi-directional promoter with rMd5-CEF but not with rMd5/Deltapp38-CEF or uninfected CEF lysates. However, rMd5/Deltapp38-CEF lysates could bind the same 73-bp promoter sequence when co-transfected with pp38-expressing plasmid (pcDNA-pp38). All these data taken together suggest pp38 plays an important role in regulating the transcriptional activity of the bi-directional promoter.

published proceedings

  • Virus Genes

author list (cited authors)

  • Ding, J., Cui, Z., Lee, L. F., Cui, X., & Reddy, S. M

citation count

  • 14

complete list of authors

  • Ding, Jiabo||Cui, Zhizhong||Lee, Lucy F||Cui, Xiaoping||Reddy, Sanjay M

publication date

  • April 2006