Estrogen receptor α L429 and A430 regulate 17β-estradiol-induced cell proliferation via CREB1.
17β-Estradiol (E2)-dependent cell proliferation requires both estrogen receptor α (ERα)-based integrated control of gene transcription and kinase pathways activation. Such coordination of intracellular E2:ERα-dependent signaling mechanisms is finely tuned by receptor association with specific partner proteins. Recently, we identified the leucine (L) 429 and alanine (A) 430 within the ERα ligand binding domain as important residues for receptor non-covalent interaction to ubiquitinated species [i.e., ERα ubiquitin-binding surface (ERα UBS)] and for E2-induced ERα activation. To date, if these two ERα amino acids are involved in the control of E2-dependent pathways required for cell proliferation is unknown. Here, by using stably expressing ERα mutated in L429 and A430 (i.e., L429A,A430G-LAAG) cell lines, we show that L429 and A430 are critical for E2-induced cell proliferation, PI3K/AKT pathway activation, and ERα-mediated transcriptional changes. Moreover, we demonstrate that these two receptor structural determinants direct the E2-induced PI3K/AKT/CREB1 pathway activation and CREB1-mediated transcriptional activity that in turn control the hormone-induced cell proliferation. As a whole, our data demonstrate for the first time that the ERα UBS contributes to the modulation of E2-induced ERα-mediated cell proliferation and provide a novel connection between the receptor structure and the functional molecular mechanisms by which E2:ERα complex can regulate cell processes.
Department of Science, Section Biomedical Sciences and Technology, University Roma Tre, Viale Guglielmo Marconi, 446, I-00146 Rome, Italy.
Valeria
V
Pesiri
Department of Science, Section Biomedical Sciences and Technology, University Roma Tre, Viale Guglielmo Marconi, 446, I-00146 Rome, Italy.
Pierangela
P
Totta
Department of Science, Section Biomedical Sciences and Technology, University Roma Tre, Viale Guglielmo Marconi, 446, I-00146 Rome, Italy.
Marco
M
Segatto
Molecular Medicine Program, Department of Experimental Oncology, European Institute of Oncology, Milan, Italy.
Fabrizio
F
Bianchi
Department of Science, Section Biomedical Sciences and Technology, University Roma Tre, Viale Guglielmo Marconi, 446, I-00146 Rome, Italy.
Valentina
V
Pallottini
Department of Science, Section Biomedical Sciences and Technology, University Roma Tre, Viale Guglielmo Marconi, 446, I-00146 Rome, Italy.
Maria
M
Marino
Department of Science, Section Biomedical Sciences and Technology, University Roma Tre, Viale Guglielmo Marconi, 446, I-00146 Rome, Italy. Electronic address: filippo.acconcia@uniroma3.it.
Filippo
F
Acconcia
D000409:Alanine / Q000235:genetics; D001665:Binding Sites; D049109:Cell Proliferation; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism*; D004958:Estradiol / Q000502:physiology*; D047628:Estrogen Receptor alpha / Q000235:genetics / Q000378:metabolism*; D057809:HEK293 Cells; D006801:Humans; D007930:Leucine / Q000235:genetics; D020125:Mutation, Missense; D015398:Signal Transduction; D015533:Transcriptional Activation
C115163:CREB1 protein, human; D017362:Cyclic AMP Response Element-Binding Protein; C506487:ESR1 protein, human; D047628:Estrogen Receptor alpha; D004958:Estradiol; D007930:Leucine; D000409:Alanine
17β-Estradiol signaling; CREB1; Cell proliferation; Estrogen receptor; Ubiquitin binding domains