purinergic nucleotide receptor activity

Definition

Target type: molecularfunction

Combining with a purine nucleotide and transmitting the signal from one side of the membrane to the other to initiate a change in cell activity. [GOC:mah, GOC:signaling]

Purinergic nucleotide receptors are a diverse group of transmembrane receptors that bind to purine and pyrimidine nucleotides, such as ATP, ADP, AMP, UTP, and UDP. These receptors play crucial roles in various physiological processes, including neurotransmission, inflammation, cell proliferation, and vascular tone regulation. Their molecular function involves the following key aspects:

1. **Ligand Binding:** Purinergic receptors exhibit high affinity for their specific nucleotide ligands. ATP and ADP are the primary ligands for P2 receptors, while UTP and UDP are preferred by P2Y receptors. Binding of these ligands to the extracellular domain of the receptor initiates a signaling cascade.

2. **Signal Transduction:** Upon ligand binding, conformational changes occur in the receptor structure, triggering intracellular signaling pathways. This involves activation of G proteins, which can then activate downstream effector molecules such as phospholipase C, adenylyl cyclase, and ion channels.

3. **Cellular Responses:** The activation of purinergic receptors leads to a wide range of cellular responses, including:

- **Calcium Signaling:** P2Y receptors, particularly P2Y1, P2Y2, and P2Y4, are known to mediate calcium signaling by activating phospholipase C, which hydrolyzes PIP2 to produce IP3. IP3 then triggers calcium release from intracellular stores.

- **Cyclic AMP Production:** P2Y receptors, such as P2Y1 and P2Y11, can activate adenylyl cyclase, leading to the production of cAMP, a key second messenger involved in various cellular processes.

- **Ion Channel Modulation:** P2X receptors are ligand-gated ion channels that open upon ATP binding, allowing the influx of cations such as sodium and calcium.

- **Cell Proliferation and Differentiation:** Purinergic receptors play a role in cell growth and development by influencing signaling pathways involved in these processes.

4. **Modulation of Cell Function:** Purinergic receptors contribute to the regulation of various cell functions, including:

- **Neurotransmission:** ATP serves as a neurotransmitter in both the central and peripheral nervous systems, acting on P2X and P2Y receptors to modulate neuronal activity.

- **Inflammation:** Purinergic receptors are implicated in inflammatory responses, with ATP acting as a pro-inflammatory mediator that activates immune cells.

- **Vascular Tone Regulation:** P2Y receptors on vascular smooth muscle cells influence blood vessel dilation and constriction, contributing to the regulation of blood pressure.

- **Tissue Repair and Regeneration:** Purinergic receptors are involved in the repair and regeneration of tissues after injury, promoting cell migration and proliferation.

5. **Diverse Receptor Subtypes:** Purinergic receptors comprise a large family with various subtypes, each exhibiting distinct ligand binding properties, signal transduction mechanisms, and cellular responses. This diversity allows for the fine-tuning of purinergic signaling in different tissues and cell types.

In summary, purinergic nucleotide receptor activity encompasses ligand binding, signal transduction, diverse cellular responses, and modulation of various cellular functions. Their involvement in numerous physiological processes highlights their crucial role in maintaining cellular homeostasis and regulating organismal function.'
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Proteins (6)

Compounds (47)