JC virus T' proteins encoded by alternatively spliced early mRNAs enhance T antigen-mediated viral DNA replication in human cells

The frequency of transformation of rodent fibroblasts by polyomavirus is enhanced by a viral gene product, large T-antigen. However, this effect of large T-antigen cannot be demonstrated with pBR322-cloned viral DNA. Recently, it was discovered that pBR322 contains cis-acting sequences inhibitory to DNA replication in mammalian cells. Because polyomavirus large T-antigen is required for viral DNA replication, we examined the possibility that our inability to demonstrate a requirement for large T-antigen in transformation with pBR322-cloned viral DNA was due to the failure of the chimeric DNA to replicate in the transfected cells. To this end we constructed polyomavirus recombinant molecules with a plasmid (pML-2) that lacks these "poison" sequences and measured their capacity to transform cells. Here we report that recombinant plasmids capable of replicating in the transfected cells transform these cells at frequencies approximately sixfold greater than their replication-defective counterparts.

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DnaJ/hsp40 chaperone domain of SV40 large T antigen promotes efficient viral DNA replication.

Genes & Development ◽

10.1101/gad.11.9.1098 ◽

1997 ◽

Vol 11 (9) ◽

pp. 1098-1110 ◽

Cited By ~ 139

Author(s):

K S Campbell ◽

K P Mullane ◽

I A Aksoy ◽

H Stubdal ◽

J Zalvide ◽

...

Keyword(s):

Dna Replication ◽

T Antigen ◽

Large T Antigen ◽

Sv40 Large T Antigen ◽

Viral Dna ◽

Viral Dna Replication

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Polyomavirus-plasmid recombinants capable of replicating have an enhanced transforming potential.

Molecular and Cellular Biology ◽

10.1128/mcb.3.9.1670 ◽

1983 ◽

Vol 3 (9) ◽

pp. 1670-1674 ◽

Cited By ~ 1

Author(s):

W J Muller ◽

M A Naujokas ◽

J A Hassell

Keyword(s):

Dna Replication ◽

Mammalian Cells ◽

T Antigen ◽

Viral Gene ◽

Large T Antigen ◽

Viral Dna ◽

Viral Dna Replication ◽

Transfected Cells ◽

Cis Acting ◽

Viral Gene Product

The frequency of transformation of rodent fibroblasts by polyomavirus is enhanced by a viral gene product, large T-antigen. However, this effect of large T-antigen cannot be demonstrated with pBR322-cloned viral DNA. Recently, it was discovered that pBR322 contains cis-acting sequences inhibitory to DNA replication in mammalian cells. Because polyomavirus large T-antigen is required for viral DNA replication, we examined the possibility that our inability to demonstrate a requirement for large T-antigen in transformation with pBR322-cloned viral DNA was due to the failure of the chimeric DNA to replicate in the transfected cells. To this end we constructed polyomavirus recombinant molecules with a plasmid (pML-2) that lacks these "poison" sequences and measured their capacity to transform cells. Here we report that recombinant plasmids capable of replicating in the transfected cells transform these cells at frequencies approximately sixfold greater than their replication-defective counterparts.

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