HCK

HCK (hematopoietic cell kinase) is a myristoylated Src-family tyrosine kinase expressed predominantly in granulocytes, monocytes and macrophages. Downstream of Fc-gamma, integrin and cytokine receptors, HCK participates in neutrophil chemotaxis, degranulation and the respiratory burst that generates microbicidal reactive oxygen species, and it regulates macrophage cytokine release and podosome formation. The HIV-1 Nef protein exploits HCK, binding its SH3 domain with high affinity to activate the kinase and perturb myeloid cell function during infection. Elevated HCK activity contributes to differentiation arrest in acute myeloid leukemia and chronic myelomonocytic leukemia, and dasatinib and other Src-family inhibitors can induce differentiation responses, making HCK a pharmacologically relevant kinase in myeloid disease.