Atomic structure of the GCSF-receptor complex showing a new cytokine-receptor recognition scheme

Granulocyte colony-stimulating factor (GCSF) is the principal growth factor regulating the maturation, proliferation and differentiation of the precur sor cells of neutrophilic granulocytes' and is used to treat neutropenia(2) , GCSF is a member of the long-chain subtype of the class 1 cytokine superf amily, which includes growth hormone, erythropoietin, interleukin 6 and onc ostatin M (ref. 3), Here we have determined the crystal structure of GCSF c omplexed to the BN-BC domains, the principal ligand-binding region of the G CSF receptor (GCSFR). The two receptor domains form a complex in a 2:2 rati o with the ligand, with a noncrystallographic pseudo-twofold axis through p rimarily the interdomain region and secondarily the BC domain. This structu ral view of a gp130-type receptor-ligand complex presents a new molecular b asis for cytokine-receptor recognition.