Regulation of estrogen receptor transcriptional enhancement by the cyclin A/Cdk2 complex Academic Article Article uri icon


MeSH Major

  • Cytokines
  • Glucocorticoids
  • Signal Transduction


  • We have found that ectopic expression of cyclin A increases hormone-dependent and hormone-independent transcriptional activation by the estrogen receptor in vivo in a number of cell lines, including HeLa cells, U-2 OS osteosarcoma cells and Hs 578Bst breast epithelial cells. This effect can be further enhanced in HeLa cells by the concurrent expression of the cyclin-dependent kinase activator, cyclin H, and cdk7, and abolished by expression of the cdk inhibitor, p27(KIP1), or by the expression of a dominant negative catalytically inactive cdk2 mutant. ER is phosphorylated between amino acids 82 and 121 in vitro by the cyclin A/cdk2 complex and incorporation of phosphate into ER is stimulated by ectopic expression of cyclin A in vivo. Together, these results strongly suggest a direct role for the cyclin A/cdk2 complex in phosphorylating ER and regulating its transcriptional activity.

publication date

  • September 16, 1997



  • Academic Article


Digital Object Identifier (DOI)

  • 10.1073/pnas.94.19.10132

PubMed ID

  • 9294175

Additional Document Info

start page

  • 10132

end page

  • 7


  • 94


  • 19