“…The major forms, the 289 residue (R) and the 243R proteins (resulting from the 13S and 12S mRNAs, respectively), interact with a variety of cellular proteins including cell cycle regulators, epigenetic regulators and transcription factors [ 5 , 6 , 42 , 43 , 44 , 45 , 46 ]. These interactions, among other functions, serve to enhance viral gene expression, alter the cellular gene expression profile, modulate the function of host proteins, and induce mitogenic activity within the host cell to promote a productive infection [ 9 , 37 , 47 , 48 , 49 ]. The 55 kDa protein product from the E1B region has been implicated in the ubiquitination of cellular proteins (e.g., p53), the inactivation of cellular DNA damage response and the regulation of viral mRNA export [ 50 , 51 ].…”