P2 receptor may refer to:
Nucleotide
Nucleotides are Organic compound, organic molecules composed of a nitrogenous base, a pentose sugar and a phosphate. They serve as monomeric units of the nucleic acid polymers – deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), both o ...
s, if released into the extracellular environment, can lead to cell death or other harmful cellular consequences. To avoid cellular damage, nucleotides should be neutralized, which is accomplished by P2 receptors. Almost every cell type expresses P2 receptors. Purinergic signalling also has a pathophysiological role in several immune cells including calcium mobilization, actin polymerization, chemotaxis, the release of mediators, cell maturation, cytotoxicity, and cell death etc.
Depending on the nature of the receptor they are found to be of two types:
*
P2Y receptors (
metabotropic
A metabotropic receptor, also referred to by the broader term G-protein-coupled receptor, is a type of membrane receptor that initiates a number of metabolic steps to modulate cell activity. The nervous system utilizes two types of receptors: me ...
)
*
P2X receptors (
ionotropic
Ligand-gated ion channels (LICs, LGIC), also commonly referred to as ionotropic receptors, are a group of transmembrane ion-channel proteins which open to allow ions such as Na+, K+, Ca2+, and/or Cl− to pass through the membrane in res ...
)
P is for purinergic, P2 refers to ATP receptors, as opposed to P1 adenosine
adenosine receptor
The adenosine receptors (or P1 receptors) are a class of Purinergic receptor, purinergic G protein-coupled receptors with adenosine as the endogenous ligand (biochemistry), ligand. There are four known types of adenosine receptors in humans: Aden ...
s.
P2X receptors are ATP activated channels that allow the passage of ions across cell membranes.
P2Y receptors are ATP activated
G protein-coupled receptor
G protein-coupled receptors (GPCRs), also known as seven-(pass)-transmembrane domain receptors, 7TM receptors, heptahelical receptors, serpentine receptors, and G protein-linked receptors (GPLR), form a large group of evolutionarily related ...
s (GPCRs) that initiate an intracellular chain of reactions.
Extracellular ATP and the related purine and pyrimidine nucleotides exert their functions via signalling through membrane-bound purinergic P2 receptors. These receptors are widely expressed throughout the body on various immune and nonimmune cells.
[ P2X receptors are ionotropic receptors while P2Y are GPCR type receptors. P2X receptor family encompasses 7 genes. P2Y family has 8 receptors that can be divided into two sub-families depending upon the structural similarity. P2X receptors are activated with ATP while P2Y receptors are activated by diphosphates, triphosphates, purines, pyrimidines, etc.]
References
G protein-coupled receptors
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