TY - JOUR
T1 - Unpaired extracellular cysteine mutations of CSF3R mediate gain or loss of function
AU - Zhang, Haijiao
AU - Means, Sophie
AU - Schultz, Anna Reister
AU - Watanabe-Smith, Kevin
AU - Medeiros, Bruno C.
AU - Bottomly, Daniel
AU - Wilmot, Beth
AU - McWeeney, Shannon K.
AU - Kükenshöner, Tim
AU - Hantschel, Oliver
AU - Tyner, Jeffrey W.
N1 - Publisher Copyright:
©2017 AACR.
PY - 2017/8/15
Y1 - 2017/8/15
N2 - Exclusive of membrane-proximal mutations seen commonly in chronic neutrophilic leukemia (e.g., T618I), functionally defective mutations in the extracellular domain of the G-CSF receptor (CSF3R) have been reported only in severe congenital and idiopathic neutropenia patients. Here, we describe the first activating mutation in the fibronectin-like type III domain of the extracellular region of CSF3R (W341C) in a leukemia patient. This mutation transformed cells via cysteine-mediated intermolecular disulfide bonds, leading to receptor dimerization. Interestingly, a CSF3R cytoplasmic truncation mutation (W791X) found on the same allele as the extracellular mutation and the expansion of the compound mutation was associated with increased leukocytosis and disease progression of the patient. Notably, the primary patient sample and cells transformed by W341C and W341C/W791X exhibited sensitivity to JAK inhibitors. We further showed that disruption of original cysteine pairs in the CSF3R extracellular domain resulted in either gain- or loss-of-function changes, part of which was attributable to cysteine-mediated dimer formation. This, therefore, represents the first characterization of unpaired cysteines that mediate both gain- and loss-of-function phenotypes. Overall, our results show the structural and functional importance of conserved extracellular cysteine pairs in CSF3R and suggest the necessity for broader screening of CSF3R extracellular domain in leukemia patients.
AB - Exclusive of membrane-proximal mutations seen commonly in chronic neutrophilic leukemia (e.g., T618I), functionally defective mutations in the extracellular domain of the G-CSF receptor (CSF3R) have been reported only in severe congenital and idiopathic neutropenia patients. Here, we describe the first activating mutation in the fibronectin-like type III domain of the extracellular region of CSF3R (W341C) in a leukemia patient. This mutation transformed cells via cysteine-mediated intermolecular disulfide bonds, leading to receptor dimerization. Interestingly, a CSF3R cytoplasmic truncation mutation (W791X) found on the same allele as the extracellular mutation and the expansion of the compound mutation was associated with increased leukocytosis and disease progression of the patient. Notably, the primary patient sample and cells transformed by W341C and W341C/W791X exhibited sensitivity to JAK inhibitors. We further showed that disruption of original cysteine pairs in the CSF3R extracellular domain resulted in either gain- or loss-of-function changes, part of which was attributable to cysteine-mediated dimer formation. This, therefore, represents the first characterization of unpaired cysteines that mediate both gain- and loss-of-function phenotypes. Overall, our results show the structural and functional importance of conserved extracellular cysteine pairs in CSF3R and suggest the necessity for broader screening of CSF3R extracellular domain in leukemia patients.
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U2 - 10.1158/0008-5472.CAN-17-1052
DO - 10.1158/0008-5472.CAN-17-1052
M3 - Article
C2 - 28652245
AN - SCOPUS:85028312879
SN - 0008-5472
VL - 77
SP - 4258
EP - 4267
JO - Cancer Research
JF - Cancer Research
IS - 16
ER -