In this study, we show that 80 % of the autonomous BaF3 clones, selected in our in vitro model, acquired
activating point mutations in the kinase or pseudokinase domain of JAK1.
Altogether, beside the
mutations targeting the JH1 / JH2 interface, the other
activating mutations found in this study
point to two other hotspots for the regulation of JAK enzymatic activity: the hinge region and in the loop formed between β2 - and β3 - strand in the kinase domain.