Temperature-sensitive mutant p53 (ala143) interferes transiently with DNA-synthesis and cell-cycle progression in Saos-2 cells.
It has been demonstrated that temperature-sensitive mutant p53 (val-->ala143) inhibits cell-proliferation at the permissive temperature, albeit to a lesser extent than wild-type p53 (Zhang et al.: EMBO J 13:2535-2544, 1994). We have studied its effect on the cell-cycle by dual-parameter flow cytometry, extended pulse-labeling, and pulse-chase experiments. p53ala143 interferes in Saos-2 cells at three levels with cell-cycle progression at permissive temperatures: it caused a G1-arrest, a reduced rate of DNA synthesis during S, and a prolonged G2/M. Strikingly, all these effects are transient. Continued culturing at 32 degrees C resulted in normal cell-cycle progression. Abrogation of the G1-block occurred even in the presence of high p21Waf1 protein levels, a negative cell-cycle regulator of which the expression is induced by wild-type p53.
van Laar
T
T
Laboratory of Molecular Carcinogenesis, Sylvius Laboratories, Leiden University, The Netherlands.
Schouten
R
R
Jochemsen
A G
AG
Terleth
C
C
van der Eb
A J
AJ
D001859:Bone Neoplasms / Q000473:pathology; D002453:Cell Cycle; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins / Q000096:biosynthesis / Q000235:genetics; D004247:DNA / Q000032:analysis; D004261:DNA Replication; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic; D016158:Genes, p53; D006801:Humans; D009687:Nuclear Proteins; D012516:Osteosarcoma / Q000473:pathology; D017354:Point Mutation; D011487:Protein Conformation; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis / Q000235:genetics; D051736:Proto-Oncogene Proteins c-mdm2; D011994:Recombinant Proteins / Q000378:metabolism; D013696:Temperature; D014158:Transcription, Genetic; D014162:Transfection; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000737:chemistry / Q000378:metabolism*
C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; D011994:Recombinant Proteins; D016159:Tumor Suppressor Protein p53; D004247:DNA; C497206:MDM2 protein, human; D051736:Proto-Oncogene Proteins c-mdm2