Cleavage of transcriptional activator Oct-1 by poliovirus encoded protease 3Cpro.
In HeLa cells, RNA polymerase II mediated transcription is severely inhibited by poliovirus infection. Both basal and activated transcription are affected to bring about a complete shutoff of host cell transcription. We demonstrate here that the octamer binding transcription factor, Oct-1, is cleaved in HeLa cells infected with poliovirus. Incubation of Oct-1 with the purified, recombinant 3Cpro results in the generation of the cleaved Oct-1 product seen in virus infected cells. Poliovirus infection leads to the formation of altered Oct-1 DNA complexes that can also be generated by incubation of Oct-1 with purified 3Cpro. We also show that Oct-1 cleaved by 3Cpro loses its ability to inhibit transcriptional activation by the SV40 B enhancer. These results suggest that cleavage of Oct-1 in poliovirus infected cells leads to the loss of its activity.
Yalamanchili
P
P
Department of Microbiology and Immunology, UCLA School of Medicine 90095-1747, USA.
Weidman
K
K
Dasgupta
A
A
D000086042:3C Viral Proteases; D003546:Cysteine Endopeptidases / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000502:physiology*; D006367:HeLa Cells; D051863:Host Cell Factor C1; D006801:Humans; D050811:Octamer Transcription Factor-1; D011051:Poliomyelitis / Q000821:virology*; D017955:Poliovirus / Q000502:physiology*; D014157:Transcription Factors / Q000502:physiology*; D014158:Transcription, Genetic; D014764:Viral Proteins; D014779:Virus Replication
D004268:DNA-Binding Proteins; C497692:HCFC1 protein, human; D051863:Host Cell Factor C1; D050811:Octamer Transcription Factor-1; C494165:POU2F1 protein, human; D014157:Transcription Factors; D014764:Viral Proteins; D003546:Cysteine Endopeptidases; D000086042:3C Viral Proteases