Cytokine receptor common subunit beta (CSF2RB) (CSF2RB)

The Cytokine receptor common subunit beta (CSF2RB), widely known as the beta-common receptor (βc) or CD131, is a vital signaling component shared by the receptors for interleukin-3 (IL-3), interleukin-5 (IL-5), and granulocyte-macrophage colony-stimulating factor (GM-CSF). Although each of these cytokines initially binds to a specific alpha subunit (IL-3Rα, IL-5Rα, or GMRα), the recruitment of the CSF2RB subunit is essential for forming a high-affinity dodecameric complex that initiates intracellular signaling through the JAK2/STAT5, MAPK, and PI3K pathways. Biologically, the receptor regulates the growth, differentiation, and survival of various hematopoietic cells, particularly myeloid lineages such as eosinophils, neutrophils, and macrophages. In disease states, overactivation or overexpression of the receptor is associated with asthma, chronic obstructive pulmonary disease (COPD), and myeloid leukemias like AML, making it an attractive target for multi-cytokine blockade. Conversely, loss-of-function mutations in the CSF2RB gene are a known cause of pulmonary alveolar proteinosis (PAP), a rare condition where surfactant accumulates in the lungs due to impaired macrophage clearance.

Other names

CD131Common beta chainCytokine receptor common subunit betaInterleukin-3 receptor subunit betaInterleukin-5 receptor subunit betaGranulocyte-macrophage colony-stimulating factor receptor subunit betaCDw131betaGMR

The beta-common receptor acts as the shared signaling subunit for the IL-3, IL-5, and GM-CSF receptors; therapeutic antagonists such as the monoclonal antibody CSL311 block the common cytokine-binding site (site 2) on the receptor, preventing the assembly of high-affinity receptor complexes and subsequent activation of JAK2-mediated downstream pathways like STAT5 and MAPK.