Activation of SV40 DNA replication in vitro by cellular protein phosphatase 2A.

Published

Journal Article

We have made use of the cell-free SV40 DNA replication system to identify and characterize cellular proteins required for efficient DNA synthesis. One such protein, replication protein C (RP-C), was shown to be involved with SV40 large T antigen in the early stages of viral DNA replication in vitro. We demonstrate here that RP-C is identical to the catalytic subunit of cellular protein phosphatase 2A (PP2Ac). The purified protein dephosphorylates specific phosphoamino acid residues in T antigen, consistent with the hypothesis that SV40 DNA replication is regulated by modulating the phosphorylation state of the viral initiator protein. We also show that purified RP-C/PP2Ac preferentially stimulates SV40 DNA replication in extracts from early G1 phase cells. This finding suggests that the activity of a cellular factor that influences the net phosphorylation state of T antigen is cell cycle dependent.

Full Text

Duke Authors

Cited Authors

  • Virshup, DM; Kauffman, MG; Kelly, TJ

Published Date

  • December 1989

Published In

Volume / Issue

  • 8 / 12

Start / End Page

  • 3891 - 3898

PubMed ID

  • 2555176

Pubmed Central ID

  • 2555176

Electronic International Standard Serial Number (EISSN)

  • 1460-2075

International Standard Serial Number (ISSN)

  • 0261-4189

Digital Object Identifier (DOI)

  • 10.1002/j.1460-2075.1989.tb08568.x

Language

  • eng