Figure 2.

CSF1R downstream signaling in myeloid cells. The binding region of CSF-1 or IL-34 to CSF1R is contained in the second and third domain (D2 and D3) of the extracellular region, D4 mediates homotypic interactions. Upon binding to the ligand, CSF1R dimerizes inducing tyrosine phosphorylation that will lead to activation of downstream signaling pathways. This will promote proliferation, survival, and differentiation of the cell. The intracellular region, apart from the tyrosine residues, contains an ATP-binding domain as well as catalytic domains where substrates bind (Kin). When activation takes place, these domains will fold to phosphorylate signaling mediators.