Functional interference between the Spi-1/PU.1 oncoprotein and steroid hormone or vitamin receptors.
The Spi-1/PU.1 protein is an Ets-related transcription factor, whose overexpression is a consequence of SFFV integration in Friend erythroleukemic cells. We present evidence that Spi-1/PU.1 can specifically repress the glucocorticoid-induced activation of promoters carrying a glucocorticoid response element (GRE). Conversely, the glucocorticoid receptor (GR) represses Spi-1/PU.1-mediated transcriptional activation in the presence of hormone. Spi-1/PU.1 also antagonized activation by other nuclear receptors, such as the thyroid hormone or the retinoic acid receptors, in several cell lines, including K562 erythroleukemic cells. These observations suggest that accumulation of the Spi-1/PU.1 protein may interfere with the action of hormones in the erythrocyte differentiation pathway.
Gauthier
J M
JM
UA 1644 du CNRS, Département des Biotechnologies, Institut Pasteur, France.
Bourachot
B
B
Doucas
V
V
Yaniv
M
M
Moreau-Gachelin
F
F
D001483:Base Sequence; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors*; D005786:Gene Expression Regulation; D006801:Humans; D066298:In Vitro Techniques; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D011518:Proto-Oncogene Proteins / Q000037:antagonists & inhibitors*; D011965:Receptors, Glucocorticoid / Q000037:antagonists & inhibitors*; D012097:Repressor Proteins / Q000235:genetics; D015682:Retroviridae Proteins, Oncogenic; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured
D004268:DNA-Binding Proteins; D009838:Oligodeoxyribonucleotides; D011518:Proto-Oncogene Proteins; D011965:Receptors, Glucocorticoid; D012097:Repressor Proteins; D015682:Retroviridae Proteins, Oncogenic; C062022:v-Spi-1 protein, Friend spleen focus-forming virus