Modification of an adenovirus major late promoter-binding factor during poliovirus infection.
To further characterize the mechanism involved in poliovirus-induced inhibition of HeLa cells mRNA synthesis, in vitro formation of DNA-protein complexes between nuclear upstream stimulatory transcription factor (USF) and the adenovirus type 2 major late promoter upstream promoter element (UPE; located between -45 and -65 base pairs) was studied. Using the gel shift assay, we found differences between the UPE-protein complex formed with partially purified nuclear extracts from poliovirus-infected HeLa cells and that obtained in the presence of mock-infected extracts. Formation of the modified UPE-USF complex coincided with virus-induced inhibition of host cell RNA synthesis in vivo and with a less efficient in vitro transcriptional activity of the nuclear extracts from infected cells. Furthermore, using a cross-linking protocol, we found that the host 46-kilodalton UPE-binding USF factor was severely diminished and that a virus-induced or -modified 50-kilodalton polypeptide appeared to be specifically bound to the UPE template.
Lazard
D
D
Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del IPN, México, D.F.
Fernández-Tomás
C
C
Gariglio
P
P
Weinmann
R
R
D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D017955:Poliovirus / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D012313:RNA / Q000096:biosynthesis; D012319:RNA Polymerase II / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism*; D014764:Viral Proteins
D004268:DNA-Binding Proteins; C051096:MLTF protein, adenovirus; D014157:Transcription Factors; D014764:Viral Proteins; D012313:RNA; D004247:DNA; D012319:RNA Polymerase II