Selective activation of estrogen receptor-α or -β attenuates cardiac hypertrophy and fibrosis in aldosterone-salt treated rats; a proteomic approach to identify specific target genes for ER-α and ER-β by 2D-DIGE and MALDI-TOF

2006 ◽  
Vol 40 (6) ◽  
pp. 947
Author(s):  
Paula-Anahi Arias Loza ◽  
Kai Hu ◽  
Ludwig Neyses ◽  
Christa Hegele-Hartung ◽  
Karl Heinrich Fritzemeier ◽  
...  
Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 623
Author(s):  
Marit Rasmussen ◽  
Susanna Tan ◽  
Venkata S. Somisetty ◽  
David Hutin ◽  
Ninni Elise Olafsen ◽  
...  

ADP-ribosylation is a post-translational protein modification catalyzed by a family of proteins known as poly-ADP-ribose polymerases. PARP7 (TIPARP; ARTD14) is a mono-ADP-ribosyltransferase involved in several cellular processes, including responses to hypoxia, innate immunity and regulation of nuclear receptors. Since previous studies suggested that PARP7 was regulated by 17β-estradiol, we investigated whether PARP7 regulates estrogen receptor α signaling. We confirmed the 17β-estradiol-dependent increases of PARP7 mRNA and protein levels in MCF-7 cells, and observed recruitment of estrogen receptor α to the promoter of PARP7. Overexpression of PARP7 decreased ligand-dependent estrogen receptor α signaling, while treatment of PARP7 knockout MCF-7 cells with 17β-estradiol resulted in increased expression of and recruitment to estrogen receptor α target genes, in addition to increased proliferation. Co-immunoprecipitation assays revealed that PARP7 mono-ADP-ribosylated estrogen receptor α, and mass spectrometry mapped the modified peptides to the receptor’s ligand-independent transactivation domain. Co-immunoprecipitation with truncated estrogen receptor α variants identified that the hinge region of the receptor is required for PARP7-dependent mono-ADP-ribosylation. These results imply that PARP7-mediated mono-ADP-ribosylation may play an important role in estrogen receptor positive breast cancer.


2005 ◽  
Vol 25 (13) ◽  
pp. 5417-5428 ◽  
Author(s):  
Christopher C. Valley ◽  
Raphaël Métivier ◽  
Natalia M. Solodin ◽  
Amy M. Fowler ◽  
Mara T. Mashek ◽  
...  

ABSTRACT The ubiquitin-proteasome pathway has emerged as an important regulatory mechanism governing the activity of several transcription factors. While estrogen receptor α (ERα) is also subjected to rapid ubiquitin-proteasome degradation, the relationship between proteolysis and transcriptional regulation is incompletely understood. Based on studies primarily focusing on the C-terminal ligand-binding and AF-2 transactivation domains, an assembly of an active transcriptional complex has been proposed to signal ERα proteolysis that is in turn necessary for its transcriptional activity. Here, we investigated the role of other regions of ERα and identified S118 within the N-terminal AF-1 transactivation domain as an additional element for regulating estrogen-induced ubiquitination and degradation of ERα. Significantly, different S118 mutants revealed that degradation and transcriptional activity of ERα are mechanistically separable functions of ERα. We find that proteolysis of ERα correlates with the ability of ERα mutants to recruit specific ubiquitin ligases regardless of the recruitment of other transcription-related factors to endogenous model target genes. Thus, our findings indicate that the AF-1 domain performs a previously unrecognized and important role in controlling ligand-induced receptor degradation which permits the uncoupling of estrogen-regulated ERα proteolysis and transcription.


2021 ◽  
Vol 118 (44) ◽  
pp. e2114258118
Author(s):  
Takahiro Masaki ◽  
Makoto Habara ◽  
Yuki Sato ◽  
Takahiro Goshima ◽  
Keisuke Maeda ◽  
...  

Estrogen receptor α (ER-α) mediates estrogen-dependent cancer progression and is expressed in most breast cancer cells. However, the molecular mechanisms underlying the regulation of the cellular abundance and activity of ER-α remain unclear. We here show that the protein phosphatase calcineurin regulates both ER-α stability and activity in human breast cancer cells. Calcineurin depletion or inhibition down-regulated the abundance of ER-α by promoting its polyubiquitination and degradation. Calcineurin inhibition also promoted the binding of ER-α to the E3 ubiquitin ligase E6AP, and calcineurin mediated the dephosphorylation of ER-α at Ser294 in vitro. Moreover, the ER-α (S294A) mutant was more stable and activated the expression of ER-α target genes to a greater extent compared with the wild-type protein, whereas the extents of its interaction with E6AP and polyubiquitination were attenuated. These results suggest that the phosphorylation of ER-α at Ser294 promotes its binding to E6AP and consequent degradation. Calcineurin was also found to be required for the phosphorylation of ER-α at Ser118 by mechanistic target of rapamycin complex 1 and the consequent activation of ER-α in response to β-estradiol treatment. Our study thus indicates that calcineurin controls both the stability and activity of ER-α by regulating its phosphorylation at Ser294 and Ser118. Finally, the expression of the calcineurin A–α gene (PPP3CA) was associated with poor prognosis in ER-α–positive breast cancer patients treated with tamoxifen or other endocrine therapeutic agents. Calcineurin is thus a promising target for the development of therapies for ER-α–positive breast cancer.


2020 ◽  
Author(s):  
Manabu Kojima ◽  
Kotaro Sugimoto ◽  
Mizuko Tanaka ◽  
Yuta Endo ◽  
Naoki Ichikawa-Tomikawa ◽  
...  

AbstractCell adhesion proteins not only maintain tissue integrity but also possess signaling abilities to organize diverse cellular events in physiological and pathological processes; however, the underlying mechanism remains obscure. Among cell adhesion molecules, the claudin (CLDN) family often possesses aberrant expression in various cancers, but the biological relevance and molecular basis have not yet been established. Here, we show that high CLDN6 expression promotes endometrial cancer progression and represents the poor prognostic marker. The second extracellular domain and Y196/200 of CLDN6 were required to recruit and activate Src-family kinases (SFKs) and to stimulate malignant phenotypes. Importantly, we demonstrate that the CLDN6/SFK/PI3K-dependent AKT and SGK (serum- and glucocorticoid-regulated kinase) signalings target Ser518 in the human estrogen receptor α and ligand-independently activate target genes in endometrial cancer cells, resulting in cancer development. The identification of this machinery highlights regulation of the transcription factors by cell adhesion to advance tumor progression.


2007 ◽  
Vol 39 (4) ◽  
pp. 249-259 ◽  
Author(s):  
Saad El Marzouk ◽  
Jennifer R Schultz-Norton ◽  
Varsha S Likhite ◽  
Ian X McLeod ◽  
John R Yates ◽  
...  

AbstractEstrogen receptor α (ERα) is a ligand-activated transcription factor that regulates expression of estrogen-responsive genes. Upon binding of the ligand-occupied ERα to estrogen response elements (EREs) in DNA, the receptor interacts with a variety of coregulatory proteins to modulate transcription of target genes. We have isolated and identified a number of proteins associated with the DNA-bound ERα. One of these proteins, Rho guanosine diphosphate (GDP) dissociation inhibitor α (RhoGDIα), is a negative regulator of the Rho family of GTP-binding proteins. In this study, we demonstrate that endogenously expressed RhoGDIα is present in the nucleus as well as the cytoplasm of MCF-7 breast cancer cells, and that RhoGDIα binds directly to ERα, alters the ERα–ERE interaction, and influences the ability of ERα to regulate transcription of a heterologous estrogen-responsive reporter plasmid in transient transfection assays as well as endogenous, estrogen-responsive genes in MCF-7 cells. Our studies suggest that, in addition to the activity of RhoGDIα in the cytoplasm, it also influences ERα signaling in the nucleus.


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