Serotonin Receptor 3A Protein is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
| HTR3A | |
|---|---|
| Protein Name | 5-Hydroxytryptamine Receptor 3A |
| Gene | [HTR3A](/genes/htr3a) |
| UniProt ID | [P23978](https://www.uniprot.org/uniprot/P23978) |
| PDB IDs | 6Y0Z, 7XP3 |
| Molecular Weight | 55.0 kDa |
| Subcellular Localization | Plasma Membrane (Ligand-Gated Ion Channel) |
| Protein Family | Cys-Loop Receptor, Ion Channel |
The HTR3A protein forms a pentameric ligand-gated ion channel, a member of the Cys-loop receptor superfamily. Each subunit consists of an extracellular N-terminal domain containing the characteristic Cys-loop motif, followed by four transmembrane domains (TM1-TM4). The ion channel pore is formed by the TM2 helices of each subunit. The receptor can form as homomeric HTR3A assemblies or heteromeric assemblies with HTR3B subunits, which modify channel properties. The extracellular domain contains the binding site for serotonin and allosteric modulators.
The 5-HT3 receptor is the only ionotropic serotonin receptor (1-7). Unlike other serotonin receptors that are GPCRs, HTR3A functions as a cation channel that conducts Na+, K+, and Ca2+ ions upon serotonin binding. Activation causes rapid depolarization and neuronal excitation. In the brain, HTR3A is expressed in areas involved in emesis, pain perception, mood, and cognition. It plays roles in:
5-HT3A receptor expression in the brain:
HTR3A is implicated in neurodegenerative diseases through various mechanisms:
The study of Serotonin Receptor 3A Protein has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.
Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.