Fc alpha receptor I (FcαRI)

Fc alpha receptor I (FcαRI), also known as CD89, is a cell surface receptor that specifically binds to the Fc region of immunoglobulin A (IgA). It plays a crucial role in immune defense by mediating both pro-inflammatory and anti-inflammatory responses depending on the context of IgA binding. It is composed of an α-chain and associates with a dimeric γ-chain containing ITAMs essential for signal transduction. Key roles include mediating endocytosis/phagocytosis, triggering ADCC, and modulating inflammatory responses. In disease contexts such as glomerulonephritis progression, activation initiates cascades promoting leukocyte recruitment.

Other names

CD89FCAR

Binding to IgA leading to downstream signaling cascades involving ITAM phosphorylation and recruitment of Src-family kinases, ultimately triggering effector functions such as phagocytosis, ADCC, and cytokine release.