JGV logo ARTICLE ABSTRACT 
 DOI: 10.1099/vir.0.19395-0
 Online 22 August 2003

Baculovirus P35 interacts with a subunit of human RNA polymerase II and can enhance promoter activity in human cells

David Takramah,1 Barbara M. Seiffert,1 Sophie Schaller,2 Marc Vigneron2 and Georg Häcker1

1Institute for Medical Microbiology, Immunology and Hygiene, Technische Universität München, Trogerstr. 9, D-81675 Munich, Germany
2Institut de Genetique et de Biologie Moleculaire et Cellulaire (CNRS/INSERM/ULP), Illkirch, France



The early protein P35 from the baculovirus Autographa californica nucleopolyhedrovirus is a direct inhibitor of caspases and can block apoptosis in a wide variety of systems. In addition, it has been linked to the regulation of viral gene expression, shut-down of protein synthesis in infected insect cells and malignant transformation of mouse fibroblasts. By yeast-two-hybrid screening we identified the RPB11a subunit of human RNA polymerase II as an interaction partner of P35. Specificity of the interaction was confirmed by affinity blotting. By immunocytology, P35 was in part found in the nucleus of transfected cells. Homology searches further revealed that P35 has structural similarity with RPB3, the subunit of RNA polymerase II that has been demonstrated to interact directly with RPB11a. When transfected into human colon carcinoma cells, P35 was able to enhance the activity of E-cadherin and beta-actin promoters by about a factor of two as measured by luciferase reporter assay. P35 and hRPB11a together enhanced the E-cadherin activity about three- to fourfold. These data suggest an additional role for P35 in the regulation of cellular transcription.

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© 2003 SGM

This article is available in the November 2003 issue of JGV (vol. 84, 3011-3019). The complete issue of the journal may be seen in electronic form on JGV Online.