GM-CSF R alpha Proteins and Enzymes

The high affinity receptor for granulocyte-macrophage colony stimulating factor (GM-CSF) consists of two subunits; an 80 kDa cytokine-specific alpha-subunit (CD116), and a 120 kDa non-specific, signal transducing beta-subunit (CD131). Analogous with other cytokine signaling mechanisms, CD131 is also shared with the cytokine specific alpha-subunits of the IL-3 and IL-5 receptors. In the absence of CD131, the CD116 alpha-subunit binds GM-CSF with low affinity. GM-CSF receptors are highly expressed on neutrophils, monocytes, oligodendrocytes, megakaryocytes, eosinophils, and myeloid leukemia cells.