Short communicationAmino acids 1–29 of the adenovirus serotypes 12 and 2 E1A proteins interact with rap30 (TFIIF) and TBP in vitro

Early region 1A (E1A) gene products of adenoviruses (Ad) play an essential role in both productive infection and cellular transformation. Besides their function to induce the expression of all other adenoviral genes they modulate the expression of specific cellular genes to ensure an efficient viral reproduction. Gene regulatory functions of E1A proteins are mainly located in the conserved regions 1–3 (CRs) and in the non-conserved amino terminal end and are mediated via protein/protein interactions with cellular factors. We could show recently, that the E1A N-terminus (amino acids [aa] 1–29) of oncogenic Ad12 contains a unique `trans'-activation domain. Here we demonstrate that this region binds to rap30/TFIIF and to the TATA-box binding protein TBP in vitro. Mutation analyses suggest that binding to rap30 and `trans'-activation are two independent functions as a mutant which failed to interact with rap30 was still able to induce gene expression with wildtype efficiency. Moreover loss of transcriptional activity does not correlate with a loss of TBP binding suggesting that this association is not necessary for the N-terminal `trans'-activating activity. Interestingly, aa 1–29 of Ad2 E1A binds also to rap30 indicating that this interaction might be a common feature of E1A proteins from different serotypes.