[4] However, this chain alone cannot perform signaling in response to IgA binding, and FcαRI must associate with a dimeric form of FcR g-chain, the ends of which contain immunoreceptor tyrosine-based activation motifs (ITAMs).

[7] The SNP results in either serine or glycine as the 248th residue of the amino acid sequence, a position in the intracellular domain of FcαRI.

[7] Alternative splicing of the transcript from this gene produces ten mRNA variants encoding different isoforms.

[3] FcαRI must first be primed by a process called inside-out signaling in order to bind with increased ability to IgA.

Priming occurs when cytokines signaling the presence of an infection bind their receptors on FcαRI-expressing cells, activating the kinase PI3K.

A pro-inflammatory response is signaled when IgA molecules in an immune complex bind to multiple FcαRI, resulting in the activation of Src family kinases and the phosphorylation of the FcR γ-chain ITAMs by Lyn.

[9] The ensuing signaling cascades lead to pro-inflammatory responses such as release of cytokines, phagocytosis, respiratory bursts, antibody-dependent cell-mediated cytotoxicity, production of reactive oxygen species, and antigen presentation.

[5] Secreted IgA plays an important role in preventing immune response to commensal gut microbes, and accordingly intestinal macrophages do not express FcαRI.