ER alpha/ESR1 Protein, Human (His)

The ER α/ESR1 protein is a nuclear receptor that plays a critical regulatory role in gene expression, affecting cell proliferation and differentiation. Ligand-dependent transactivation involves binding of homodimers to estrogen response elements or association with transcription factors. ER alpha/ESR1 Protein, Human (His) is the recombinant human-derived ER alpha/ESR1 protein, expressed by E. coli , with N-6*His labeled tag. The total length of ER alpha/ESR1 Protein, Human (His) is 116 a.a., with molecular weight of 12-14 kDa.

ER alpha/ESR1 Protein, a nuclear hormone receptor, plays a pivotal role in the regulation of eukaryotic gene expression, influencing cellular proliferation and differentiation in target tissues. Ligand-dependent nuclear transactivation involves direct homodimer binding to palindromic estrogen response element (ERE) sequences or association with DNA-binding transcription factors like AP-1/c-Jun, c-Fos, ATF-2, Sp1, and Sp3, facilitating ERE-independent signaling. Upon ligand binding, ER alpha undergoes a conformational change, enabling subsequent association with multiprotein coactivator complexes through LXXLL motifs. Mutual transrepression occurs between ER alpha and NF-kappa-B in a cell-type specific manner, leading to decreased NF-kappa-B DNA-binding activity and inhibition of NF-kappa-B-mediated transcription. ER alpha is recruited to NF-kappa-B response elements, displacing coregulators and mediating transcriptional activation synergistically with NF-kappa-B. Moreover, ER alpha participates in membrane-initiated estrogen signaling through various kinase cascades, and is essential for MTA1-mediated transcriptional regulation of BRCA1 and BCAS3. Additionally, ER alpha is involved in the activation of NOS3 and endothelial nitric oxide production. Isoforms lacking specific functional domains are believed to modulate transcriptional activity through competitive ligand or DNA binding, as well as heterodimerization with the full-length receptor. Furthermore, ER alpha binds to ERE and inhibits isoform 1.

Measured by its binding ability in a functional ELISA. When Recombinant Human ESR1 is present at 10 μg/mL can bind Anti- ESR1 antibody. The ED₅₀ for this effect is 0.445 μg/mL.

Human

E. coli

N-6*His

P03372 (M1-Q116)

2099  [NCBI]

MTMTLHTKASGMALLHQIQGNELEPLNRPQLKIPLERPLGEVYLDSSKPAVYNYPEGAAYEFNAAAAANAQVYGQTGLPYGPGSEAAAFGSNGLGGFPPLNSVSPSPLMLLHPPPQ

Approximately 12-14 kDa

Greater than 90% as determined by reducing SDS-PAGE.

Lyophilized powder

Lyophilized from a 0.2 μm filtered solution of 20 mM Glycine-HCl, 8% Sucrose, 0.05% Tween 80, pH 3.5 or 50 mM Tris-HCL, 150 mM NaCl, pH 8.0.

<1 EU/μg, determined by LAL method.

It is not recommended to reconstitute to a concentration less than 100 μg/mL in ddH₂O. For long term storage it is recommended to add a carrier protein (0.1% BSA, 5% HSA, 10% FBS or 5% Trehalose).

Stored at -20°C for 2 years. After reconstitution, it is stable at 4°C for 1 week or -20°C for longer (with carrier protein). It is recommended to freeze aliquots at -20°C or -80°C for extended storage.

Room temperature in continental US; may vary elsewhere.