Phosphorylation of human progesterone receptors at serine-294 by mitogen-activated protein kinase signals their degradation by the 26S proteasome.

@article{Lange2000PhosphorylationOH,
  title={Phosphorylation of human progesterone receptors at serine-294 by mitogen-activated protein kinase signals their degradation by the 26S proteasome.},
  author={Carol A. Lange and Tang-Long Shen and Kathryn B. Horwitz},
  journal={Proceedings of the National Academy of Sciences of the United States of America},
  year={2000},
  volume={97 3},
  pages={1032-7}
}
Ligand-dependent down-regulation that leads to rapid and extensive loss of protein is characteristic of several nuclear steroid receptors, including human progesterone receptors (PRs). In breast cancer cells, >95% of PRs are degraded 6 h after the start of progestin treatment. The mechanism for down-regulation is unknown. We examined the role of PR phosphorylation by mitogen-activated protein kinases (MAPKs) in this process. Lactacystin and calpain inhibitor I, specific inhibitors of the 26S… CONTINUE READING