Thyroid hormone promotes serine phosphorylation of p53 by mitogen-activated protein kinase.
L-Thyroxine (T(4)) nongenomically promotes association of mitogen-activated protein kinase (MAPK) and thyroid hormone receptor TRbeta1 (TR) in the cell nucleus, leading to serine phosphorylation of the receptor. The oncogene suppressor protein, p53, is serine phosphorylated by several kinases and is known to interact with TRbeta1. We studied whether association of p53 and TR is modulated by T(4) and involves serine phosphorylation of p53 by MAPK. TR-replete 293T human kidney cells were incubated with a physiological concentration of T(4) for 10-90 min. Nuclear fractions were immunoprecipitated and the resulting proteins separated and immunoblotted for co-immunoprecipitated proteins. Activated MAPK immunoprecipitates of nuclei from T(4)-treated cells accumulated p53 in a time-dependent manner; T(4) and T(4)-agarose were more effective than T(3). T(4)-induced nuclear complexing of p53 and MAPK was inhibited by PD 98059 (PD) and U0126, two MAPK kinase (MEK) inhibitors, and was absent in cells treated with MEK antisense oligonucleotide and in dominant negative Ras cells. T(4) also caused nuclear co-immunoprecipitation of TRbeta1 and p53, an effect also inhibited by PD. Nuclear complexing of p53 and MAPK also occurred in HeLa cells, which lack functional TR. Constitutively activated MAPK caused phosphorylation of a recombinant p53-GST fusion protein in vitro; thus, p53 is a substrate for MAPK. An indicator of p53 transcriptional activity, accumulation of the immediate-early gene product, c-Jun, was inhibited by T(4). This T(4) effect was reversed by PD, indicating that the transcriptional activity of p53 was altered by T(4)-directed MAPK-p53 interaction.
Shih
A
A
Stratton VA Medical Center, Molecular and Cellular Medicine Program, Department of Medicine, Albany Medical College, and Wadsworth Center, New York State Department of Health, Albany, New York 12208, USA.
Lin
H Y
HY
Davis
F B
FB
Davis
P J
PJ
D016475:3T3 Cells; D000818:Animals; D002458:Cell Fractionation; D002460:Cell Line; D002467:Cell Nucleus / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006367:HeLa Cells; D006801:Humans; D048369:MAP Kinase Kinase 1; D020935:MAP Kinase Signaling System / Q000187:drug effects; D051379:Mice; D020929:Mitogen-Activated Protein Kinase Kinases / Q000235:genetics / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism; D016376:Oligonucleotides, Antisense / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism; D011988:Receptors, Thyroid Hormone / Q000378:metabolism; D000077185:Resveratrol; D012694:Serine / Q000378:metabolism*; D013267:Stilbenes / Q000494:pharmacology; D013974:Thyroxine / Q000031:analogs & derivatives* / Q000494:pharmacology*; D014162:Transfection; D014284:Triiodothyronine / Q000494:pharmacology; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
D004791:Enzyme Inhibitors; D009687:Nuclear Proteins; D016376:Oligonucleotides, Antisense; D016755:Proto-Oncogene Proteins c-jun; D011988:Receptors, Thyroid Hormone; D013267:Stilbenes; D016159:Tumor Suppressor Protein p53; D014284:Triiodothyronine; D012694:Serine; D017346:Protein Serine-Threonine Kinases; D020928:Mitogen-Activated Protein Kinases; D048369:MAP Kinase Kinase 1; C482125:MAP2K1 protein, human; C482127:Map2k1 protein, mouse; D020929:Mitogen-Activated Protein Kinase Kinases; C011126:tetraiodothyroacetic acid; D000077185:Resveratrol; D013974:Thyroxine