Protein domains connect cell cycle stimulation directly to initiation of DNA replication
| Autor: | B J Bockus, Patricia S. Holman, P. E. Rose, Ole V. Gjorup, Brian Schaffhausen |
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| Rok vydání: | 1994 |
| Předmět: |
DNA Replication
Genes Viral viruses Antigens Polyomavirus Transforming Papillomavirus E7 Proteins Eukaryotic DNA replication Biology Transfection Virus Replication Retinoblastoma Protein DNA replication factor CDT1 Mice Replication factor C Control of chromosome duplication Animals Phosphorylation Papillomaviridae S phase Multidisciplinary Cell Cycle DNA replication 3T3 Cells Oncogene Proteins Viral Molecular biology Peptide Fragments Recombinant Proteins Viral replication biology.protein Origin recognition complex Harvey murine sarcoma virus Adenovirus E1A Proteins Research Article |
| Zdroj: | Proceedings of the National Academy of Sciences. 91:12125-12129 |
| ISSN: | 1091-6490 0027-8424 |
| Popis: | Polyoma large T antigen (LT) is the only viral gene product required for viral DNA replication. LT can be divided into two domains, one N-terminal (NT) spanning residues 1-260 and one C-terminal (CT) comprising approximately residues 264-785. NT is known to immortalize primary cells in a manner dependent on binding of pRB/p107. Here a CT construct comprising residues 264-785 was shown to have independent function in DNA replication. CT is entirely sufficient for driving viral DNA replication in vivo in growing mouse cells at a level approaching that of full-length LT. In contrast, CT is strikingly deficient for replication in serum-starved cells. However, this deficiency can be complemented by coexpression of NT. BrdUrd incorporation in transfected, starved cells showed that NT was sufficient for inducing S phase, suggesting a mechanism for complementation. By contrast, CT was unable to induce S phase when tested in the same assay. NT also promotes phosphorylation of sites in CT that are likely to be important for replication. Other DNA tumor virus gene products such as adenovirus E1A 12S and human papillomavirus 16 E7 could also complement CT for replication. Although NT, E1A 12S, and E7 all bind the retinoblastoma gene product (pRB) and p107, genetic analysis demonstrates an additional function, independent of that binding, is responsible for complementation. |
| Databáze: | OpenAIRE |
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