G protein-coupled receptor
G protein-coupled receptor
The G protein-coupled receptor (GPCR), also known as seven-(pass)-transmembrane domain receptors, 7TM receptors, heptahelical receptors, serpentine receptor, and G protein-linked receptors (GPLR), is a type of protein that is located in the cell membrane and interacts with G proteins. Pronounced as "gee protein-coupled receptor".
Etymology
The term "G protein-coupled receptor" is derived from the fact that these receptors are coupled with G proteins, which are a family of proteins involved in transmitting chemical signals outside of the cell, and across the membrane, into the cell.
Structure
GPCRs are integral membrane proteins that possess seven transmembrane domains. The size of GPCRs is typically between 300-1000 amino acids. The specific size of each GPCR is dictated by its specific function and the specific ligand it interacts with.
Function
GPCRs are involved in a wide variety of physiological processes. Some examples of their roles include:
- The senses of sight, taste and smell. The photoreceptor cells in the retina, for example, are GPCRs.
- The behavioral and mood regulation.
- Regulation of immune system activity and inflammation.
- Autonomic nervous system transmission, both sympathetic and parasympathetic.
- Cell density sensing.
Related Terms
- Ligand: A substance that forms a complex with a biomolecule to serve a biological purpose.
- Transmembrane protein: A type of protein that spans the entirety of the biological membrane to which it is permanently attached.
- Signal transduction: The process by which a chemical or physical signal is transmitted through a cell as a series of molecular events.
See Also
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