April 20th seminar

Estrogen receptor

• Estrogen is steroid, so ER is intracellular.
• Dimer of alpha & beta - three possible combinations with different ratios in different tissue & different effects depending on combination.
• Classic nuclear action of regulating genes.
• Other ER membrane linked:
• Caveolin-1 causes localisation with membrane.
• Complex with g-proteins, striatin^[1], EGFR, IGF-1 etc - is ER actually attached to EGFR, or merely comminicates with it?
• ER activates EGFR, activating MAPK (ERK), JNK, and Pl3K/AKT pathways.^[2]
• GSK-3β inhibits nuclear ER activity by inhibiting Ser118 phosphorylation.
• Membrane ER signals to inhibit GSK-3β - through AKT pathway only?^[3][4]

References

1. ^  Lu, 2004.
2. ^  Levin, 2005.
3. ^  Levin, 2005.
4. ^  Kato, 1995.