Polyoma Virus Middle T Gene Can Trigger Malignant Transformation of Early Passage Rodent Cells

Spandidos, Demetrios Α.; Riggio, Marcello P.

doi:10.1099/0022-1317-67-4-793

Cited by 9 publications

(2 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The Chinese hamster lung (CHL) late passage cells and the geneticin-resistant CHL transfectant cell clones FH06LTl-1, FHO6MTl-1 and FHO6STl-1 have been described [24]. Clones FHO6LTl-1, FH06MTl-1 and FHO6STl-1 were obtained after transfection of early passage CHL cells with recombinant plasmids pHO6LT1, pHO6MTl and pHO6STl carrying the polyoma large, middle and small T antigen gene, respectively.…”

Section: Cells and Plasmidsmentioning

confidence: 99%

Differential potency and trans‐activation of normal and mutant T24 human H‐ras1 gene promoters

Spandidos

Pintzas

1988

FEBS Letters

View full text Add to dashboard Cite

We have employed a short-term transfection assay system in which we monitored the transient expression of the chloramphenicol acetyltransferase (CAT) gene linked to the promoter region of the normal and mutant T24 H-rasl gene or the human s-globin gene in Chinese hamster lung (CHL) cells or cells derived from them which carry and express one or the other of the polyoma virus early genes. Our findings can be summarized as follows: (i) The mutant T24 H-rusl promoter region behaves as a stronger promoter than the H-rasl gene in all these types of cells as well as in rat 208F fibroblast cells. (ii) In CHL cells expressing the polyoma large T antigen the normal and mutant T24 Ha-rsl promoters are not trans-activated in these cells and only a 2.5fold activation of the s-globin promoter is observed. (iii) In cells expressing the polyoma middle T antigen both the normal and mutant H-rasl are tram-activated whereas transcription from the s-globin promoter is not affected when compared to the normal CHL cells. (iv) In cells expressing the polyoma small T antigen the normal and mutant H-ru.sl as well as the s-globin promoters are trans-activated. We suggest from these data that a tissue-specific element exists in the promoter region of the H-rarl gene and that the polyoma middle and small T antigens trigger the expression of proteins that trans-activate these promoters.

show abstract

Section: Cells and Plasmidsmentioning

confidence: 99%

Differential potency and trans‐activation of normal and mutant T24 human H‐ras1 gene promoters

Spandidos

Pintzas

1988

FEBS Letters

View full text Add to dashboard Cite

show abstract

“…Polyomavirus (Py)-mediated transformation results principally from the action of one of the Py early gene products, middle T antigen (39). Middle T antigen is both necessary and sufficient to transform established (34,51) and, in some cases, embryonic cells (24,46) in culture and to induce tumors in hamsters (1), chickens (24), and transgenic mice (2,52). Middle T antigen is a phosphoprotein (17,40,41,44), is composed of 421 amino acids, and has a measured molecular weight of either 56,000 or 58,000, depending on its state of phosphorylation (41).…”

mentioning

confidence: 99%

The amino terminus of polyomavirus middle T antigen is required for transformation

Cook

Hassell

1990

J Virol

View full text Add to dashboard Cite

In polyomavirus-transformed cells, pp60c-src is activated by association with polyomavirus middle T antigen. These complexes have a higher tyrosine kinase activity compared with that of unassociated pp60c-src. Genetic analyses have revealed that the carboxy-terminal 15 amino acids of pp60c-src and the amino-terminal half of middle T antigen are required for this association and consequent activation of the tyrosine kinase. To define in greater detail the borders of the domain in middle T antigen required for activation of pp60c-src, we constructed a set of unidirectional amino-terminal deletion mutants of middle T antigen. Analysis of these mutants revealed that the first six amino acids of middle T antigen are required for it to activate the kinase activity of pp60c-src and to transform Rat-1 fibroblasts. Analysis of a series of insertion and substitution mutants confirmed these observations and further revealed that mutations affecting the first four amino acids of middle T antigen reduced or abolished its capacity to activate the kinase activity of pp60c-src and to transform Rat-1 cells in culture. Our results suggest that the first four amino acids of middle T antigen constitute part of a domain required for activation of the pp60c-src tyrosyl kinase activity and for consequent cellular transformation.

show abstract

Immortalization of primary cells by DNA tumor viruses

Linder

Marshall

1990

Experimental Cell Research

View full text Add to dashboard Cite

Polyoma Virus Middle T Gene Can Trigger Malignant Transformation of Early Passage Rodent Cells

Cited by 9 publications

References 24 publications

Differential potency and trans‐activation of normal and mutant T24 human H‐ras1 gene promoters

Differential potency and trans‐activation of normal and mutant T24 human H‐ras1 gene promoters

The amino terminus of polyomavirus middle T antigen is required for transformation

Immortalization of primary cells by DNA tumor viruses

Contact Info

Product

Resources

About