Phosphorylation-dependent activation of the adenovirus-inducible E2F transcription factor in a cell-free system.

AUTOR(ES)

Bagchi, S

RESUMO

Adenovirus infection induces a large increase in the DNA binding activity of a cellular transcription factor that is utilized by the viral E2 promoter and termed E2F. Using cell-free extracts, we have developed an assay for the in vitro activation of DNA binding activity of E2F. E2F activity is undetectable in HeLa extracts but upon incubation with a fraction from adenovirus-infected cells, there is an ATP-dependent increase in E2F DNA binding activity. This increase does not occur using an equivalent fraction from dl312 (E1A-)-infected cells. Incubation of E2F with phosphatase inactivates E2F binding activity. Incubation of the phosphatase-inactivated E2F with an infected cell fraction restores E2F activity as does incubation with a known protein kinase. In contrast, incubation with an extract from mock-infected cells does not restore activity. We conclude that the DNA binding activity of E2F is regulated by phosphorylation in an E1A-dependent manner.

Documentos Relacionados

• The adenovirus-inducible factor E2F stimulates transcription after specific DNA binding.
• Splicing of adenovirus RNA in a cell-free transcription system.
• Mechanism of estrogen receptor-dependent transcription in a cell-free system.
• Inactivation by sequence-specific methylations of adenovirus promoters in a cell-free transcription system.
• Translation in Saccharomyces cerevisiae: initiation factor 4E-dependent cell-free system.