Estradiol-induced phosphorylation of ERK1/2 in explants of the mouse cerebral cortex: the roles of heat shock protein 90 (Hsp90) and MEK2.
Confocal laser scanning microscopy was used to identify the cells within organotypic slice cultures of the developing mouse cerebral cortex that respond to estradiol treatment by phosphorylation of ERK1 and ERK2. Estrogen-responsive cells resembled neurons morphologically and expressed the neuronal marker microtubule-associated protein 2B. The intracellular distribution of the phospho-ERK signal was both cytoplasmic and nuclear, but inhibition of protein synthesis abolished the appearance of the nuclear signal. ERK1and ERK2 also coimmunoprecipitated with heat shock protein 90 (Hsp90) in the cerebral cortical explants. Geldanamycin effectively disrupted this association and prevented ERK phosphorylation. Surprisingly, MEK2 but not MEK1 was the principal mediator of estradiol-induced activation of ERK. Our data demonstrate the requirement for Hsp90 in estrogen-induced activation of ERK1 and ERK2 by MEK2 in the developing mouse cerebral cortex and also provide insight into alternative mechanisms by which estradiol may influence cytoplasmic and nuclear events in responsive neurons via the MAP kinase cascade.
Sétáló
György
G
Department of Anatomy and Cell Biology, Columbia University College of Physicians and Surgeons, New York, New York 10032.
Singh
Meharvan
M
Guan
Xiaoping
X
Toran-Allerand
C Dominique
CD
D000818:Animals; D000831:Animals, Newborn; D016227:Benzoquinones; D002540:Cerebral Cortex / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004958:Estradiol / Q000494:pharmacology*; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism*; D007150:Immunohistochemistry; D047029:Lactams, Macrocyclic; D048370:MAP Kinase Kinase 2; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000502:physiology; D051379:Mice; D018613:Microscopy, Confocal; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D009924:Organ Culture Techniques; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011809:Quinones / Q000494:pharmacology*
D016227:Benzoquinones; D004791:Enzyme Inhibitors; D018841:HSP90 Heat-Shock Proteins; D047029:Lactams, Macrocyclic; D011809:Quinones; D004958:Estradiol; D011505:Protein-Tyrosine Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D048370:MAP Kinase Kinase 2; D020929:Mitogen-Activated Protein Kinase Kinases; C001277:geldanamycin