Dataset Information

Palmitoylation of estrogen receptors is essential for neuronal membrane signaling.

ABSTRACT: In addition to activating nuclear estrogen receptor signaling, 17?-estradiol can also regulate neuronal function via surface membrane receptors. In various brain regions, these actions are mediated by the direct association of estrogen receptors (ERs) activating metabotropic glutamate receptors (mGluRs). These ER/mGluR signaling partners are organized into discrete functional microdomains via caveolin proteins. A central question that remains concerns the underlying mechanism by which these subpopulations of ERs are targeted to the surface membrane. One candidate mechanism is S-palmitoylation, a posttranscriptional modification that affects the subcellular distribution and function of the modified protein, including promoting localization to membranes. Here we test for the role of palmitoylation and the necessity of specific palmitoylacyltransferase proteins in neuronal membrane ER action. In hippocampal neurons, pharmacological inhibition of palmitoylation eliminated 17?-estradiol-mediated phosphorylation of cAMP response element-binding protein, a process dependent on surface membrane ERs. In addition, mutation of the palmitoylation site on estrogen receptor (ER) ? blocks ER?-mediated cAMP response element-binding protein phosphorylation. Similar results were obtained after mutation of the palmitoylation site on ER?. Importantly, mutation of either ER? or ER? did not affect the ability of the reciprocal ER to signal at the membrane. In contrast, membrane ER? and ER? signaling were both dependent on the expression of the palmitoylacyltransferase proteins DHHC-7 and DHHC-21. Neither mGluR activity nor caveolin or ER expression was affected by knockdown of DHHC-7 and DHHC-21. These data collectively suggest discrete mechanisms that regulate specific isoform or global membrane ER signaling in neurons separate from mGluR activity or nuclear ER function.

SUBMITTER: Meitzen J

PROVIDER: S-EPMC3800757 | biostudies-literature | 2013 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Palmitoylation of estrogen receptors is essential for neuronal membrane signaling.

Meitzen John J Luoma Jessie I JI Boulware Marissa I MI Hedges Valerie L VL Peterson Brittni M BM Tuomela Krista K Britson Kyla A KA Mermelstein Paul G PG

Endocrinology 20130905 11

In addition to activating nuclear estrogen receptor signaling, 17β-estradiol can also regulate neuronal function via surface membrane receptors. In various brain regions, these actions are mediated by the direct association of estrogen receptors (ERs) activating metabotropic glutamate receptors (mGluRs). These ER/mGluR signaling partners are organized into discrete functional microdomains via caveolin proteins. A central question that remains concerns the underlying mechanism by which these subp ...[more]

PMID: 24008343

Similar Datasets

Project description:BackgroundEstrogen receptors (ERs) are thought to play an important role in non-small cell lung cancer (NSCLC). However, the effect of ERs in NSCLC is still controversial and needs further investigation. A new consideration is that ERs may affect NSCLC progression through complicated molecular signaling networks rather than individual targets. Therefore, this study aims to explore the effect of ERs in NSCLC from the perspective of cancer systems biology.MethodsThe gene expression profile of NSCLC samples in TCGA dataset was analyzed by bioinformatics method. Variations of cell behaviors and protein expression were detected in vitro. The kinetic process of molecular signaling network was illustrated by a systemic computational model. At last, immunohistochemical (IHC) and survival analysis was applied to evaluate the clinical relevance and prognostic effect of key receptors in NSCLC.ResultsBioinformatics analysis revealed that ERs might affect many cancer-related molecular events and pathways in NSCLC, particularly membrane receptor activation and signal transduction, which might ultimately lead to changes in cell behaviors. Experimental results confirmed that ERs could regulate cell behaviors including cell proliferation, apoptosis, invasion and migration; ERs also regulated the expression or activation of key members in membrane receptor signaling pathways such as epidermal growth factor receptor (EGFR), Notch1 and Glycogen synthase kinase-3β/β-Catenin (GSK3β/β-Catenin) pathways. Modeling results illustrated that the promotive effect of ERs in NSCLC was implemented by modulating the signaling network composed of EGFR, Notch1 and GSK3β/β-Catenin pathways; ERs maintained and enhanced the output of oncogenic signals by adding redundant and positive-feedback paths into the network. IHC results echoed that high expression of ERs, EGFR and Notch1 had a synergistic effect on poor prognosis of advanced NSCLC.ConclusionsThis study indicated that ERs were likely to promote NSCLC progression by modulating the integrated membrane receptor signaling network composed of EGFR, Notch1 and GSK3β/β-Catenin pathways and then affecting tumor cell behaviors. It also complemented the molecular mechanisms underlying the progression of NSCLC and provided new opportunities for optimizing therapeutic scheme of NSCLC.

Project description:The novel neuroproteasome is localized to the neuronal plasma membrane to degrade intracellular proteins into peptides that are released to the extracellular space. Selective inhibition of this neuronal membrane proteasome (NMP) complex ceased the release of peptides and rapidly attenuated neuronal transmission. Based on these findings, we hypothesize that these neuron-specific peptides mediate a novel form of communication through unique peptide-receptor interactions to promote intracellular signaling cascades relevant to neuronal development and function. Our work indicates that NMP peptides can rapidly induce N-methyl-D-aspartate receptor (NMDAR)-dependent calcium influx from dendrites to the soma, leading to rapid and sustained phosphorylation of the well-defined activity-dependent transcription factor cAMP response element-binding protein (CREB). We also determined that the gene expression program drastically changes upon NMP peptide treatment of neurons with an increase in expression of immediate early genes (e.g., Fos, Npas4, Egr4) known to have critical neuroregulatory roles. These data support our current thinking that NMP peptides are endogenous and selective activators of synaptic NMDA receptors and are critical for promoting activity-dependent gene expression. This pathway is orthogonal to the classic neurotransmitters previously described to activate NMDARs and points to NMP and its resulting peptides as key contributors to the development and function of the nervous system. However, the unique peptide sequences leading to neuronal activation are still poorly understood. Here, we show that the NMP peptides have tremendous sequence diversity through an unbiased peptidomic approach, and the current ongoing effort is to identify unique active peptide sequences with distinct receptor specificity. Elucidating the mechanism of the NMP and its active peptide products is crucial to understanding the role of this novel signaling process in the nervous system.

Project description:Uterine leiomyomas or fibroids are the most common tumors of the female reproductive tract. Estrogen (E2), a steroid-derived hormone, and its receptors (ERs), particularly ER-α, are important drivers for the development and growth of leiomyomas. We previously demonstrated that simvastatin, a drug used for hyperlipidemia, also possesses anti-leiomyoma properties. The aim of this work is to investigate the impact of simvastatin on ER-α signaling in leiomyoma cells, including its expression, downstream signaling, transcriptional activity, post-translational modification, trafficking and degradation. Primary and immortalized human uterine leiomyoma (HuLM) cells were used for in vitro experiments. Immunodeficient mice xenografted with human leiomyoma tissue explants were used for in vivo studies. Leiomyoma samples were obtained from patients enrolled in an ongoing double-blinded, phase II, randomized controlled trial. Here, we found that simvastatin significantly reduced E2-induced proliferation and PCNA expression. In addition, simvastatin reduced total ER-α expression in leiomyoma cells and altered its subcellular localization by inhibiting its trafficking to the plasma membrane and nucleus. Simvastatin also inhibited E2 downstream signaling, including ERK and AKT pathways, E2/ER transcriptional activity and E2-responsive genes. To explain simvastatin effects on ER-α level and trafficking, we examined its effects on ER-α post-translational processing. We noticed that simvastatin reduced ER-α palmitoylation; a required modification for its stability, trafficking to plasma membrane, and signaling. We also observed an increase in ubiquitin-mediated ER-α degradation. Importantly, we found that the effects of simvastatin on ER-α expression were recapitulated in the xenograft leiomyoma mouse model and human tissues. Thus, our data suggest that simvastatin modulates several E2/ER signaling targets with potential implications in leiomyoma therapy and beyond.

Dataset Information

Palmitoylation of estrogen receptors is essential for neuronal membrane signaling.

Publications

Palmitoylation of estrogen receptors is essential for neuronal membrane signaling.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets