Cyclic AMP specifically blocks proliferation of rat 3T3 cells transformed by polyomavirus.
AUTOR(ES)
Kamech, N
RESUMO
Elevated exogenous and intracellular levels of cyclic AMP could totally block proliferation of polyomavirus (PyV) transformants derived from rat 3T3 cells without affecting proliferation of normal cells or simian virus 40 (SV40)-induced transformants. Concanavalin A (ConA) had the opposite effect; it could totally block proliferation of both normal cells and SV40 transformants but reduced proliferation of PyV transformants only twofold. Adenylate cyclase was threefold less active in membranes of PyV transformants, and the number of ConA receptors was similar to that of normal cells. Proliferating PyV transformants contained threefold less cyclic AMP than did proliferating SV40 transformants. The sensitivity to cyclic AMP did not correlate with the degree of transformation: cells transformed by Rous sarcoma virus and tumor cells derived from SV40 transformants were not sensitive to cyclic AMP. The differential effect of cyclic AMP and ConA on proliferation was probably due to the activity of an intact middle t protein. The presence of both large T and small t together with middle t was also required for cyclic AMP sensitivity.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=254134Documentos Relacionados
- Properties of cells transformed by the middle T-antigen-coding region of polyomavirus.
- Cyclic AMP: a mitogenic signal for Swiss 3T3 cells.
- Polyomavirus transforms rat F111 and mouse NIH 3T3 cells by different mechanisms.
- A Mutant of 3T3 Cells with Cyclic AMP Metabolism Sensitive to Temperature Change
- A 61,000-dalton truncated large T-antigen is uniformly expressed in hamster cells transformed by polyomavirus.
