A receptor is a specialized structure composed of protein that receives and transduces signals in biological systems, such as cells or organisms
. Receptors are present in various parts of the body, including the immune system, sense organs, and other cells
. They play crucial roles in regulating cell binding, signal transduction, membrane channels, immune responses, immunotherapy, and cell metabolism
. There are different types of receptors based on their location and function:
- Internal receptors : Located inside the cell, they include growth factor receptors, such as neurotrophin receptor, FGF receptor, EGF receptor, IGF receptor, and PDGF receptor
- Cell-surface receptors : Found on the cell surface, they can be further classified into three main types
:
* Ion channel receptors: When a ligand binds to an ion channel receptor, a channel opens in the plasma membrane, allowing specific ions to pass through
* G-protein-coupled receptors (GPCRs): These receptors act through a G-protein to start a second messenger cascade, modulating cellular function
* Enzyme-linked receptors: These receptors are linked to enzymes, which can be activated or inhibited by the binding of a ligand
Receptors are involved in various functions, such as regulating cell binding, helping in signal transduction, controlling membrane channels, and inducing cell metabolisms, including cell growth, cell division, and cell death
