Sci. STKE, 6 June 2000
Immunology FcRI Complexes are Better with Beta
The FcRI complex exists in two forms composed of α and subunits in the presence or absence of β subunits: α2, and αβ 2. The presence of the β subunit in FcRI increases the transduced signal to approximately 5 times that of β-deficient FcRIs. Donnadieu et al. uncover another method by which β subunits increase FcRI signal amplification: increasing the amounts of α subunit found at the plasma membrane. Cells stably expressing the α 2 receptor express higher levels of functional FcRI when also transfected with the β chain. Expression of the β chain in α 2 cells led to increased maturation of α, and the authors also demonstrated that α and β associate early in the ER compartment. Additionally, the stability of the functional FcRI complex, as measured by protein-protein associations within immune complexes, is increased in the presence of the β chain. Thus, the presence of the β chain in FcRI appears to increase receptor density and receptor stability and suggests that the different FcRI isoforms may have specific roles in differing cell types.
Donnadieu, E., Jouvin, M.-H., and Kinet, J.-P. (2000) A second amplifier function for the allergy-associated FcRI-β subunit. Immunity 12: 515-523. [Online Journal]
Citation: FcRI Complexes are Better with Beta. Sci. STKE 2000, tw4 (2000).
Science Signaling. ISSN 1937-9145 (online), 1945-0877 (print). Pre-2008: Science's STKE. ISSN 1525-8882