High affinity immunoglobulin epsilon receptor subunit beta (MS4A2)

High affinity immunoglobulin epsilon receptor subunit beta (MS4A2) is a beta chain of the tetrameric high affinity IgE receptor (FcεRI), which is mainly expressed on the surface of mast cells and basophils[1][2][3][5]. This receptor binds to the Fc region of immunoglobulin E (IgE), and upon recognition and cross-linking by allergen-bound IgE, triggers cellular activation, leading to degranulation and the release of mediators such as histamine, lipid mediators, and cytokines that drive allergic inflammation and immune responses[1][2][3][5][6]. MS4A2 is classified as a membrane protein with four transmembrane domains and is a member of the membrane spanning 4A (MS4A) family[1][3]. Variants in the MS4A2 gene are associated with susceptibility to allergic diseases such as asthma and atopy, and have been implicated by genetic studies in other conditions like Alzheimer's disease[1][3]. There are currently no drugs that directly target the MS4A2 protein itself; therapies such as anti-IgE monoclonal antibodies inhibit FcεRI pathway activity indirectly by preventing IgE engagement and receptor aggregation[2][6].

Other names

APYAtopyFCER1BFCERIIGERIGELIGHERFc epsilon receptor I beta-chainIgE Fc receptor subunit betaMembrane-spanning 4-domains subfamily A member 2High affinity IgE receptor beta subunitIgE Fc receptor, membrane spanning 4-domains A2

Anti-IgE antibodies (e.g., omalizumab) block IgE binding to FcεRI, preventing receptor aggregation and downstream allergic signaling Inhibition of FcεRI signaling pathway, suppressing mast cell/basophil activation and allergic mediator release