Moulting hormones of arthropods: Molecular mechanisms

Moulting hormone action is mediated mainly by the intracellular ecdysteroid receptor, a member of the nuclear receptor family. The receptor is compose d of several functional domains, responsible for transactivation, DNA bindi ng, ligand binding, dimerization with other nuclear receptors and interacti on with additional proteins e.g. comodulators. Receptor function is modulat ed by intramolecular interactions between receptor domains and intermolecul ar allosteric effects of various dimerization partners. Tissue-, developmen tal stage- and gene-specific diversification of the hormonal signal is nece ssary to coordinate the activity of more than 100 ecdysteroid dependent gen es. This is enabled by tissue specific hormone metabolism, posttranslationa l modification of the receptor protein, receptor isoforms, various dimeriza tion partners and interaction with different comodulators.