This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Klausing, K Articles by Knippers, R Search for Related Content PubMed PubMed Citation Articles by Klausing, K Articles by Knippers, R

 Previous Article  |  Next Article 

J Virol. 1988 April; 62(4): 1258-1265

Effects of in vitro dephosphorylation on DNA-binding and DNA helicase activities of simian virus 40 large tumor antigen.

Fakultät für Biologie, Universität Konstanz, Federal Republic of Germany.

ABSTRACT

Simian virus 40 large T antigen is a phosphoprotein with two clusters of phosphorylation sites. Each cluster includes four serine residues and one threonine residue. In vitro treatment with intestinal alkaline phosphatase removes the phosphate groups from the serine but not from the threonine residues. Potato acid phosphatase additionally dephosphorylates the phosphothreonine (Thr-124) in the N-terminal cluster but does not attack the phosphothreonine in the C-terminal cluster (Thr-701). Two biochemical functions of untreated and partially dephosphorylated T antigen were assayed, namely, its specific DNA-binding property and its DNA helicase activity. After treatment with alkaline phosphatase, T antigen had a severalfold higher affinity for the specific binding sites in the viral genomic control region, in particular, for binding site II in the origin of replication. However, T antigen, when dephosphorylated by acid phosphatase, had DNA-binding properties similar to those of the untreated control. Neither alkaline nor acid dephosphorylation affected the DNA helicase activity of T antigen.

This article has been cited by other articles:

• Fradet-Turcotte, A., Vincent, C., Joubert, S., Bullock, P. A., Archambault, J. (2007). Quantitative Analysis of the Binding of Simian Virus 40 Large T Antigen to DNA. J. Virol. 81: 9162-9174 [Abstract] [Full Text]  
• Barbaro, B. A., Sreekumar, K. R., Winters, D. R., Prack, A. E., Bullock, P. A. (2000). Phosphorylation of Simian Virus 40 T Antigen on Thr 124 Selectively Promotes Double-Hexamer Formation on Subfragments of the Viral Core Origin. J. Virol. 74: 8601-8613 [Abstract] [Full Text]  
• Zemskov, E. A., Kang, W., Maeda, S. (2000). Evidence for Nucleic Acid Binding Ability and Nucleosome Association of Bombyx mori Nucleopolyhedrovirus BRO Proteins. J. Virol. 74: 6784-6789 [Abstract] [Full Text]  
• Weisshart, K., Taneja, P., Jenne, A., Herbig, U., Simmons, D. T., Fanning, E. (1999). Two Regions of Simian Virus 40 T Antigen Determine Cooperativity of Double-Hexamer Assembly on the Viral Origin of DNA Replication and Promote Hexamer Interactions during Bidirectional Origin DNA Unwinding. J. Virol. 73: 2201-2211 [Abstract] [Full Text]  
• Lin, X.-H., Walter, J., Scheidtmann, K., Ohst, K., Newport, J., Walter, G. (1998). Protein phosphatase 2A is required for the initiation of chromosomal DNA replication. Proc. Natl. Acad. Sci. USA 95: 14693-14698 [Abstract] [Full Text]