; R o o t E n t r y F L 5 C o m p O b j b W o r d D o c u m e n t O b j e c t P o o l L 5 L 5 B C D E F G H I J K F Microsoft Word 6.0 Document MSWordDoc Word.Document.6 ; 9507034 Padmanabhan PRIVATE DNA tumor viruses, adenovirus in particular, have played a pivotal role in our current understanding of biological processes in a eukaryotic cell, such as replication, transcription, and translation, primarily due to the protein protein and protein DNA interactions involving viral and cellular regulatory sequences and proteins. The cell free adenovirus and SV40 DNA replication systems have contri`uted immensely to our current understanding of the functions of viral and host proteins that participate in the replication machinery in a eukaryotic cell. Recent evidence indicate that phosphorylation states of adenovirus DNA polymerase (AdPol) and preterminal protein (pTP) are important for their interaction with the origin of DNA replication (Ori DNA). The major phosphorylation site of AdPol has been mapped in the vicinity of its bipartite nuclear localization signal (NLS) sequence, and by site directed mutagenesis, this site has been shown to be important for its replication initiation activity. Many nuclear proteins have potential phosphorylation sites in the vicinity of their NLS. The presence of a major phosphorylation site in AdPol in a region proximal to its bipartite NLS could modulate the nucleocytoplasmic transport of AdPol and its associated proteins. Recent evidence suggests that the viral DNA polymerase is phosphorylated in vivo by an associated protein kinase of the cdc2 family. This project focuses on understanding of the role of phosphorylation in protein protein and protein- DNA interactions during DNA replication and nuclear transport. These studies are likely to shed light on (1) the role that phosphorylation plays in the protein protein and protein DNA interactions occurring during DNA replication and in nuclear transport of the replication proteins. These studies are especially important because currently the role of phosphorylation on the nuclear targeting of proteins with bipartite NLS sequences is unknown. %%% DNA tumor viruses, adenovirus in particular, have served as excellent model systems for providing a clear understanding of complex biological processes in eukaryotic cells. Many of these processes are regulated by phosphorylation/dephosphorylation reactions carried out by a number of protein kinases and phosphatases, which respond to intra as well as extracellular stimuli. In this project, the role of phosphorylation of proteins involved in DNA replication and in their intracellular location, cytoplasm versus nucleus, will be studied. This project focuses on understanding of the role of phosphorylation in protein protein and protein DNA interactions during DNA replication and intracellular localization. To achieve these specific aims, the sites of phosphorylation of replication proteins will be identified and characterized using a number of biochemical and genetic experimental approaches. *** @ ....()()))()() Z : phoenix @ Oh +' 0 $ H l D h R:WWUSERTEMPLATENORMAL.DOT marcia steinberg marcia steinberg @ m 5 @ @ 5 S u m m a r y I n f o r m a t i o n ( A @ 0 Microsoft Word 6.0 2 e = e b U " " " " " " " L L L L L d n L C x | | | | | | | #
