AIB1 Is a Conduit for Kinase-Mediated Growth Factor Signaling to the Estrogen Receptor

AUTOR(ES)

Font de Mora, Jaime

FONTE

American Society for Microbiology

RESUMO

Growth factor modulation of estrogen receptor (ER) activity plays an important role in both normal estrogen physiology and the pathogenesis of breast cancer. Growth factors are known to stimulate the ligand-independent activity of ER through the activation of mitogen-activated protein kinase (MAPK) and the direct phosphorylation of ER. We found that the transcriptional activity of AIB1, a ligand-dependent ER coactivator and a gene amplified preferentially in ER-positive breast cancers, is enhanced by MAPK phosphorylation. We demonstrate that AIB1 is a phosphoprotein in vivo and can be phosphorylated in vitro by MAPK. Finally, we observed that MAPK activation of AIB1 stimulates the recruitment of p300 and associated histone acetyltransferase activity. These results suggest that the ability of growth factors to modulate estrogen action may be mediated through MAPK activation of the nuclear receptor coactivator AIB1.

Documentos Relacionados

• Antigen receptor signaling induces MAP kinase-mediated phosphorylation and degradation of the BCL-6 transcription factor
• Mitogen-activated protein kinase-mediated Fas apoptotic signaling pathway
• Coactivator AIB1 links estrogen receptor transcriptional activity and stability
• c-Jun NH2-Terminal Kinase-Mediated Signaling Is Essential for Pseudomonas aeruginosa ExoS-Induced Apoptosis
• Insulin resistance differentially affects the PI 3-kinase– and MAP kinase–mediated signaling in human muscle