Extra-nuclear estrogen signaling

Extra-nuclear estrogen signaling In addition to its well-characterized role in estrogen-dependent transcription, estrogen (beta-estradiol, also known as E2) also plays a rapid, non-genomic role through interaction with receptors localized at the plasma membrane by virtue of dynamic palmitoylation. Estrogen receptor palmitoylation is a prerequisite for the E2-dependent activation of extra-nuclear signaling both in vitro and in animal models (Acconcia et al, 2004; Acconcia et al, 2005; Marino et al, 2006; Marino and Ascenzi, 2006). Non-genomic signaling through the estrogen receptor ESR1 also depends on receptor arginine methylation by PMRT1 (Pedram et al, 2007; Pedram et al, 2012; Le Romancer et al, 2008; reviewed in Arnal, 2017; Le Romancer et al, 2011 ).
E2-evoked extra-nuclear signaling is independent of the transcriptional activity of estrogen receptors and occurs within seconds to minutes following E2 administration to target cells. Extra-nuclear signaling consists of the activation of a plethora of signaling pathways including the RAF/MAP kinase cascade and the PI3K/AKT signaling cascade and governs processes such as apoptosis, cellular proliferation and metastasis (reviewed in Hammes et al, 2007; Handa et al, 2012; Lange et al, 2007; Losel et al, 2003; Arnal et al, 2017; Le Romancer et al, 2011). ESR-mediated signaling also cross-talks with receptor tyrosine kinase, NF- kappa beta and GPCR signaling pathways by modulating the post-translational modification of enzymes and other proteins and regulating second messengers (reviewed in Arnal et al, 2017; Schwartz et al, 2016; Boonyaratanakornkit, 2011; Biswas et al, 2005). In the nervous system, E2 affects neural functions such as cognition, behaviour, stress responses and reproduction in part by inducing such rapid extra-nuclear responses (Farach-Carson and Davis, 2003; Losel et al, 2003), while in endothelial cells, non-genomic ESR-dependent signaling also regulates vasodilation through the eNOS pathway (reviewed in Levin, 2011).
Extra-nuclear signaling additionally cross-talks with nuclear estrogen receptor signaling and is required to control ER protein stability (La Rosa et al, 2012)
Recent data have demonstrated that the membrane ESR1 can interact with various endocytic proteins to traffic and signal within the cytoplasm. This receptor intracellular trafficking appears to be dependent on the phyical interaction of ESR1 with specific trans-membrane receptors such as IGR-1R and beta 1-integrin (Sampayo et al, 2018)