PHOSPHORYLATION OF THE ADENOASSOCIATED VIRUS-REPLICATION PROTEINS

The adeno-associated virus (AAV) replication proteins Rep78 and Rep68 regulate viral gene expression and DNA amplification. Their effects on both processes suggest that they play roles in all phases of the viru s life cycle. We have investigated Rep protein phosphorylation to dete rmine if this modification might alter Rep function. All four Rep prot eins were found to be phosphorylated in AAV and adenovirus co-infected cell cultures, and Rep proteins contained phospha-serine whereas no p hospho-threonine or -tyrosine was detected. We also observed that when viral DNA synthesis was inhibited, there was a significant decrease i n the level of Rep78/68 phosphorylation. Our results suggest a plausib le mechanism whereby AAV Rep78/68 function may be regulated by phospho rylation. (C) 1997 Academic Press.