Abstract |
The infection of monkey kidney (CV-1) cells with simian virus 40 (SV40) stimulates the cells into successive rounds of DNA synthesis without an intervening mitosis, leading to the acquisition of a >G2 DNA content. To elucidate the role of small t antigen in cell cycle progression and in viral replication during infection, studies were performed using an SV40 mutant (dl888) that lacks the ability to produce small t. Initially dl888-infected cells move through the first S phase at roughly the same rate as wild-type infected cells. Upon reaching G2, however, the dl888-infected cells progressed to >G2 at a reduced rate relative to wild-type. The slower rate of entry into >G2 of dl888-infected cells is associated with a decrease in total pRb and an increase in the ratio of hypophosphorylated to hyperphosphorylated pRb. The expression of cyclin D1 and p27(kip1) were elevated in dl888-infected cells compared to wild-type-infected CV-1 cells. Taken together, these results indicate that small t antigen plays a role in stimulating entry into >G2 in SV40-infected CV-1 cells, possibly by affecting the regulation of key cell cycle proteins.
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Authors | B Whalen, J Laffin, T D Friedrich, J M Lehman |
Journal | Experimental cell research
(Exp Cell Res)
Vol. 251
Issue 1
Pg. 121-7
(Aug 25 1999)
ISSN: 0014-4827 [Print] United States |
PMID | 10438577
(Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)
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Copyright | Copyright 1999 Academic Press. |
Chemical References |
- Antigens, Polyomavirus Transforming
- Cell Cycle Proteins
- Microtubule-Associated Proteins
- Retinoblastoma Protein
- Tumor Suppressor Proteins
- Cyclin D1
- Cyclin-Dependent Kinase Inhibitor p27
- Mimosine
- DNA
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Topics |
- Animals
- Antigens, Polyomavirus Transforming
(genetics, physiology)
- Blotting, Western
- Cell Cycle
(drug effects)
- Cell Cycle Proteins
- Cell Line
- Cell Nucleus
(genetics)
- Chlorocebus aethiops
- Cyclin D1
(analysis)
- Cyclin-Dependent Kinase Inhibitor p27
- DNA
(biosynthesis)
- G2 Phase
- Gene Expression Regulation
- Kinetics
- Microtubule-Associated Proteins
(analysis)
- Mimosine
(pharmacology)
- Mutation
- Phosphorylation
- Polyploidy
- Retinoblastoma Protein
(analysis, metabolism)
- Simian virus 40
(genetics, physiology)
- Tumor Suppressor Proteins
- Virus Replication
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