complement component C3a receptor activity

Definition

Target type: molecularfunction

Combining with the C3a product of the complement cascade and transmitting the signal from one side of the membrane to the other to initiate a change in cell activity. [GOC:add, GOC:mah, GOC:pg, GOC:signaling, ISBN:0781735149]

Complement component C3a receptor (C3aR) activity is a molecular function that is crucial for the activation and regulation of the innate immune system. C3aR is a G protein-coupled receptor expressed on a variety of immune cells, including mast cells, neutrophils, eosinophils, basophils, monocytes, and macrophages. When C3a, a complement activation product, binds to C3aR, it initiates a signaling cascade that leads to the activation of downstream signaling pathways. This ultimately results in the release of inflammatory mediators, such as histamine, leukotrienes, and cytokines.

C3aR activation plays a critical role in the following key processes:

1. **Inflammation:** C3aR activation leads to the release of inflammatory mediators, which contribute to the recruitment of immune cells to the site of infection or tissue injury.

2. **Allergic responses:** C3aR is involved in allergic responses, such as anaphylaxis, by triggering the release of histamine and other inflammatory mediators from mast cells.

3. **Host defense:** C3aR contributes to host defense by promoting the phagocytosis of pathogens by macrophages and the killing of pathogens by neutrophils.

4. **Tissue repair:** C3aR activation can also promote tissue repair by stimulating the production of growth factors and cytokines that are involved in wound healing.

In addition to its role in immune responses, C3aR is also involved in a variety of other physiological processes, such as angiogenesis (formation of new blood vessels), neurotransmission, and cell proliferation.

The activation of C3aR is tightly regulated to prevent uncontrolled inflammation and tissue damage. C3aR signaling is downregulated by mechanisms such as desensitization, internalization, and degradation of the receptor.

Overall, C3aR activity is a critical molecular function that plays a central role in the activation and regulation of the innate immune system. It is involved in a wide range of physiological processes, including inflammation, allergic responses, host defense, and tissue repair.'
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Proteins (1)

Compounds (1)