Cytokine Receptors and Their Ligands

Cytokines act through their membrane-bound receptors to transmit a variety of signals including cell survival, proliferation, differentiation, and functional activity. Cytokine receptors are a conserved family of about 40 members that includes the receptors for hormones, interleukins, interferons, and colony-stimulating factors. Abnormal cytokine levels or aberrations in their signaling pathways can lead to a variety of diseases including cancers and inflammatory conditions reflecting their importance in normal hematopoiesis and immunity. Determination of the three-dimensional atomic structures of cytokines and their receptors has provided detailed insights into how cytokines transmit biological signals across cell membranes.