Mouse Complement Component 5a Receptor 1 (C5AR1) Protein

Background

C5AR1 is a G protein-coupled receptor (GPCR) that binds C5a, a potent anaphylatoxin generated during complement activation, playing a key role in immune responses and inflammation. C5AR1 is primarily expressed on immune cells, including neutrophils, macrophages, eosinophils, and mast cells, where its activation triggers chemotaxis, degranulation, and the release of pro-inflammatory cytokines. The receptor mediates downstream signaling pathways, such as PI3K/Akt, MAPK, and NF-κB, promoting cell migration, survival, and inflammatory responses. C5AR1 is crucial for host defense, facilitating immune cell recruitment to sites of infection and tissue damage. However, dysregulated C5AR1 signaling contributes to excessive inflammation in diseases such as sepsis, rheumatoid arthritis, and asthma. In cancer, C5AR1 modulates the tumor microenvironment by promoting the recruitment of immunosuppressive myeloid cells, facilitating tumor growth and immune evasion. Additionally, C5AR1 activation has been implicated in neuroinflammation, contributing to neurodegenerative diseases like Alzheimer’s. Therapeutic targeting of C5AR1 with antagonists or inhibitors is being explored to treat inflammatory diseases, autoimmune disorders, and complement-driven cancers, aiming to reduce excessive inflammation and immune dysfunction.