The complement C3a-C3a receptor Axis regulates epithelial-to-mesenchymal transition by activating the ERK pathway in pancreatic ductal adenocarcinoma. Anticancer Res. 2022 Mar;42(3):1207-1215. 35220210

C3a is a 77 residue anaphylatoxin that binds to the C3a receptor (C3aR), a class A G protein-coupled receptor. It plays a large role in the immune response. C3a molecules induce responses through the GPCR C3a receptor.

Complement activation and inactivation generate the degradation products of complement component 3 (C3; MW: 195 kDa). C3 convertases (C4b2a generated by the classical or lectin pathways, or C3bBb generated by the alternative pathway) cleave C3 into C3a (MW: 9 kDa) and C3b (MW: 185 kDa).

Sep 12, 2024 · Complement C3 (MW: 183 kDa) is one of the most abundant plasma proteins. It is a pivotal component of complement and is central to the activation cascades. The mature protein is composed of two disulfide-bound polypeptide chains (C3α and C3β).

Complement C3a was found to be elevated in patients with: - Inflammation (such as asthma) - Autoimmune diseases [C3a levels were increased in patients with severe and moderately active lupus (SLE).] - Chronic hepatitis C, and HCV-related hepatitis cell carcinoma.

In this study, with an aim to gain more insights into the function of teleost C3 and C3a, we examined the biological role of Japanese flounder (Paralichthys olivaceus) C3 (PoC3) and C3a (PoC3a) in complement activation and antibacterial immune defense.

C3: (MW 180 000), the central component of all complement reactions, split by its convertase into a small (C3a) and a large (C3b) fragment. Some of the C3b is deposited on the membrane, where it serves as an attachment site for phagocytic polymorphs and macrophages, which have receptors for it; some remains associated with C2a and C4b, forming ...

National Jewish Health Advanced Diagnostic Laboratories offers a C3a Radioimmunoassay to provide highly accurate measurements of C3a in human plasma.

molecules, C3a and C3b. The smaller C3a (MW 10,000) does not bind to the cell membrane, but is released into the fluid phase as a mediator of inflammation

Bound C3b and C3d possess stable sites that are capable of binding to specific receptors present on a limited variety of cells. We propose that all known physiologically occurring fragments of C3 arise by enzymatic cleavage of the alpha-chain: C3a, C3b, C3c, and C3d.