Figure 1.

Dynamic protein–protein interaction between estrogen receptor and PI3K regulatory subunit p85. Rat cortical neurons were exposed to E₂ (10 nm) for specific time intervals (0, 5, 10, 20, 30, and 45 min), and lysates were immunoprecipitated (IP) with either anti-p85, the regulatory subunit of PI3K, or ER (clone TE111.5D11), which principally detects ERα but can partially recognize ERβ. A, Lysates immunoprecipitated with anti-p85, the regulatory subunit of PI3K, were subsequently immunoblotted for detection of ER. A dynamic pattern of p85–ER interaction was apparent in which significant immunoreactivity of ER occurred at 10 and 30 min, with intervening uncoupling at 20 and 45 min. B, To confirm these findings, the corollary experiment was performed. Cortical neuron lysates were immunoprecipitated with anti-ER and subsequently immunoblotted with anti- p85. Evidence for an ER protein interaction with p85 occurred at 10 and 30 min, with maximal complexing of the proteins at the 30 min time point. The uncoupling of proteins was apparent at 20 and 45 min. Data are from a single experiment and are representative of three independent experiments. *p < 0.05 versus control neurons; **p < 0.01 versus control neurons. Con, Control.