Adapter protein containing an immunoreceptor tyrosine-based activation motif (ITAM) that transduces activation signals from various immunoreceptors. As a component of the high-affinity immunoglobulin E (IgE) receptor, mediates allergic inflammatory signaling in mast cells. As a constitutive component of interleukin-3 receptor complex, selectively mediates interleukin 4/IL4 production b basophils priming T-cells toward effector T-helper 2 subset. Associates with pattern recognition receptors CLEC4D and CLEC4E to form a functional signaling complex in myeloid cells. Binding of mycobacterial trehalose 6,6'-dimycolate (TDM) to this receptor complex leads to phosphorylation of ITAM, triggering activation of SYK, CARD9 and NF-kappa-B, consequently driving maturation of antigen-presenting cells and shaping antigen-specific priming of T-cells toward effector T-helper 1 and T-helper 17 cell subtypes. May function cooperatively with other activating receptors. Functionally linked to integrin beta-2/ITGB2-mediated neutrophil activation. Also involved in integrin alpha-2/ITGA2-mediated platelet activation. IgE Fc receptor is a tetramer of an alpha chain, a beta chain, and two disulfide linked gamma chains. Associates with FCGR1A; forms a functional signaling complex (By similarity). The signaling subunit of immunoglobulin gamma (IgG) Fc receptor complex. As a homodimer or a heterodimer of CD247 and FCER1G, associates with the ligand binding subunit FCGR3A to form a functional receptor complex (By similarity). Associates with CLEC6A. Interacts with CLEC4E. Interacts (via ITAM domain) with SYK (via SH2 domains); activates SYK, enabling integrin-mediated activation of neutrophils and macrophages (By similarity). Interacts with common beta chain of interleukin 3 receptor CSF2RB and recruits SYK in response to IL3 stimulation; this interaction is direct (By similarity). Interacts with CD300LH; the interaction may be indirect. Interacts with CD300LD (By similarity). Interacts with TARM1 (By similarity). Belongs to the CD3Z/FCER1G family.