Receptor refers to any biological macromolecules (namely proteins) that can bind to hormones, neurotransmitters, drugs and intracellular signaling molecules and cause changes in cell function. The receptor contains at least two active sites, one is to recognize and bind the ligand; the other is the functional active site responsible for generating the response. Among them, the functional active site can only generate the response response after binding with the ligand to form a binary complex and allosteric, thereby triggering a series of biochemical reactions, and finally leading to biological effects on the target cells. Receptors can induce cell growth, division, and death, can regulate membrane channel "switches" or regulate cell binding, and play important roles in signal transduction, immunotherapy, and immune responses.
CUSABIO has listed several types of receptors that are relatively active in the field of signal transduction and immunotherapy. Click the corresponding name to learn more.
So what is the basic function of the receptor? What are the common basic types?
As mentioned before, a receptor is a protein that can recognize and specifically bind to a biologically active chemical signal substance (namely ligand), thereby activating or triggering a series of biochemical reactions, and finally leading to the ligand specific biological effects. The function of receptors can usually be divided into two aspects: one is to recognize and bind specific ligands. Ligand refers to some signal substances that have no other functions except binding to receptors. It cannot participate in metabolism to produce useful products, nor does it directly induce any cell activity. It has no enzyme characteristics. Its only function is to notify cells. There is a special signal or stimulus in the environment; on the other hand, the recognized and received signal is accurately amplified and transmitted to the interior of the cell, activating or triggering a series of intracellular biochemical reactions, and finally leading to a specific cellular response. even if The intracellular signal is converted into an intracellular signal.
Different classification criteria have different types of receptors.
Depending on their location in the cell, receptors can be divided into two types: cell surface receptors and internal receptors. As shown in Figure 1, cell surface receptors are transmembrane proteins anchored with the cell membrane, providing access to the cell for ligands that cannot cross the plasma membrane itself. There are three main types of cell surface receptors: ion channel receptors, G protein-coupled receptors and enzyme-linked receptors. Cell surface receptors generally consist of three domains: an extracellular ligand-binding domain, a transmembrane domain, and an intracellular domain.
Internal receptors are usually located in the cytoplasm, and the receptors can only enter the nucleus after binding to the corresponding ligand. Intracellular receptors recognize and bind small lipid-soluble signaling molecules that can cross the cytoplasmic membrane, such as steroid hormones, thyroxine, vitamin D, and retinoic acid. Strictly speaking, intracellular receptors can be further divided into cytoplasmic and nuclear receptors according to whether the receptors are in the cytoplasm or nucleus. Cytoplasmic receptors are located in the cytoplasm of target cells, such as adrenocortical hormone receptors and sex hormone receptors . Nuclear receptors are located in the nucleus of target cells, such as thyroxine receptors.
Figure 1. Cell Surface Receptors and Internal Receptors
In addition, receptors can also be classified into four categories according to their protein structure, information transduction process, effector properties, receptor location and other characteristics, including ion channel receptors, G protein-coupled receptors, tyrosine-containing receptors and regulating gene expression receptors. Some receptors have subtypes, various receptors have specific distribution sites and specific functions, and some cells also have multiple receptors.
Receptor by Differentiation Cell
Receptor by Drug Target