Receptor

**Semantic type:** Amino Acid, Peptide, or Protein|Receptor

**Definition:** A protein located on the cell surface, or in the cytoplasm, that binds to a specific signaling factor, such as a hormone, antigen, or neurotransmitter, causing a conformational and functional change in the receptor molecule. The ligand-bound receptor then alters its interaction with target molecules, which leads to changes in cellular physiology through modification of the activity of one or more signal transduction pathways.

**Synonyms:** - Receptor Protein - receptor