In mouse, there are two classes of high-affinity IL3 receptors. One contains this IL3-specific beta subunit and the other contains the beta subunit also shared by high-affinity IL5 and GM-CSF receptors. Heterodimer of an alpha and a beta subunit. The WSXWS motif appears to be necessary for proper protein folding and thereby efficient intracellular transport and cell-surface receptor binding. The box 1 motif is required for JAK interaction and/or activation. Belongs to the type I cytokine receptor family. Type 4 subfamily.