Correlation between in vitro peptide binding profiles and cellular activities for estrogen receptor-modulating...

Area of Science:

• Molecular Biology
• Endocrinology
• Biochemistry

Background:

• Estrogen receptor alpha (ERalpha) conformation is modulated by ligand binding.
• ERalpha's conformational state dictates interactions with protein accessory factors.
• Understanding ligand-dependent cofactor recruitment is crucial for ERalpha function.

Purpose of the Study:

• To globally investigate ligand-based cofactor recruitment activities of ERalpha.
• To develop a method for simultaneously assessing ERalpha binding to numerous peptides.
• To correlate in vitro peptide-binding profiles with cellular activities.

Main Methods:

• Application of a flow cytometric multiplexed binding assay.
• Simultaneous determination of ERalpha binding to over 50 peptides (cofactor-derived and random phage display).
• Testing over 400 ERalpha-binding compounds to generate peptide-binding profiles.

Main Results:

• Distinct multiplexed in vitro peptide-binding profiles were observed for various compounds.
• These profiles successfully predicted ERalpha ligand effects on cellular activities like gene transcription and cell proliferation.
• Phage display peptides contributed significantly to compound-induced diversity, with some resembling corepressor motifs.

Conclusions:

• Ligand-induced ERalpha conformational changes can be profiled using a multiplexed peptide-binding assay.
• In vitro peptide-binding profiles correlate with in vivo cellular responses to ERalpha ligands.
• Phage display is a valuable tool for identifying potential ERalpha binding partners and understanding tissue-specific activities.