Baculovirus P35 interacts with a subunit of human RNA polymerase II and can enhance promoter activity in human cells.
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.
Institute for Medical Microbiology, Immunology and Hygiene, Technische Universität München, Trogerstr. 9, D-81675 Munich, Germany.
David
D
Takramah
Institute for Medical Microbiology, Immunology and Hygiene, Technische Universität München, Trogerstr. 9, D-81675 Munich, Germany.
Barbara M
BM
Seiffert
Institut de Genetique et de Biologie Moleculaire et Cellulaire (CNRS/INSERM/ULP), Illkirch, France.
Sophie
S
Schaller
Institut de Genetique et de Biologie Moleculaire et Cellulaire (CNRS/INSERM/ULP), Illkirch, France.
Marc
M
Vigneron
Institute for Medical Microbiology, Immunology and Hygiene, Technische Universität München, Trogerstr. 9, D-81675 Munich, Germany.
Georg
G
Häcker
D000595:Amino Acid Sequence; D000818:Animals; D019556:COS Cells; D019281:Dimerization; D006367:HeLa Cells; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins; D008969:Molecular Sequence Data; D017924:Nucleopolyhedroviruses / Q000737:chemistry*; D011401:Promoter Regions, Genetic; D021122:Protein Subunits; D012319:RNA Polymerase II / Q000737:chemistry / Q000378:metabolism*; D014158:Transcription, Genetic; D020798:Two-Hybrid System Techniques; D014764:Viral Proteins / Q000032:analysis / Q000737:chemistry / Q000502:physiology*
D051034:Inhibitor of Apoptosis Proteins; D021122:Protein Subunits; D014764:Viral Proteins; C086430:inhibitor of apoptosis, Nucleopolyhedrovirus; D012319:RNA Polymerase II