The adenovirus E1A N-terminal repression domain represses transcription from a chromatin template in vitro

The adenovirus repression domain of E1A 243R at the E1A N-terminus (E1A 1–80) transcriptionally represses genes involved in differentiation and cell cycle progression. E1A 1–80 represses transcription in vitro from naked DNA templates through its interaction with p300 and TFIID. E1A 1–80 can also interact with several chromatin remodeling factors and associates with chromatin in vivo. We show here that E1A 243R and E1A 1–80 can repress transcription from a reconstituted chromatin template in vitro. Temporal analysis reveals strong repression by E1A 1–80 when added at pre-activation, activation and early transcription stages. Interestingly, E1A 1–80 can greatly enhance transcription from chromatin templates, but not from naked DNA, when added at pre-initiation complex (PIC) formation and transcription-initiation stages. These data reveal a new dimension for E1A 1–80's interface with chromatin and may reflect its interaction with key players in PIC formation, p300 and TFIID, and/or possibly a role in chromatin remodeling.