Receptor

A protein found in the cell membrane, cytosol, or nucleus, controlling the reception of signals from the environment and cell-cell recognition. The main function of all receptors is to receive a signal from the environment and transmit it further into the cell. This controls internal cell processes and maintains the body’s proper functioning. Receptors are divided into nuclear receptors and membrane receptors: Nuclear receptors – intracellular proteins that bind to lipophilic signaling molecules (steroid hormones, retinoids, calcitriol), which then pass through the plasma membrane into the cytosol. Nuclear receptors (e.g., glucocorticoids) are present in the cytosol or nucleus (thyroid hormones, retinoids, calcitriol). The receptor-ligand complex binds to specific DNA segments (called hormone response elements) and activates or suppresses the activity of respective genes. Membrane receptors – transmembrane (integral) proteins with an extracellular receptor domain to which a hydrophilic ligand (hormone, neurotransmitter, growth factor) binds. When the ligand binds to the receptor, it changes its conformation and causes the release of a secondary signal mediator (cAMP, cGMP, etc.).

Source | Glossary of Most Commonly Used Biomedical Terms and Concepts | Lithuanian University of Health Sciences | Academician Professor Antanas Praškevičius, Professor Laima Ivanovienė