Novel drivers and modifiers of MPL-dependent oncogenic transformation identified by deep mutational scanning
- 23 January 2020
- journal article
- research article
- Published by American Society of Hematology in Blood
- Vol. 135 (4), 287-292
- https://doi.org/10.1182/blood.2019002561
Abstract
The single transmembrane domain (TMD) of the human thrombopoietin receptor (TpoR/MPL), encoded by exon 10 of the MPL gene, is a hotspot for somatic mutations associated with myeloproliferative neoplasms (MPNs). Approximately 6% and 14% of JAK2 V617F-negative essential thrombocythemia (ET) and primary myelofibrosis (PMF) patients, respectively, have 'canonical' MPL exon 10 driver mutations W515L/K/R/A or S505N, which generate constitutively active receptors and consequent loss of Tpo dependence. Other 'non-canonical' MPL exon 10 mutations have also been identified in patients, both alone and in combination with canonical mutations, but in almost all cases their functional consequences and relevance to disease are unknown. Here we used a deep mutational scanning (DMS) approach to evaluate all possible single-amino-acid substitutions in the human TpoR TMD for their ability to confer cytokine-independent growth in Ba/F3 cells. We identified all currently recognized driver mutations and seven novel mutations that cause constitutive TpoR activation, and a much larger number of second-site mutations that enhance S505N-driven activation. We found examples of both of these categories in published and previously unpublished MPL exon 10 sequencing data from MPN patients, demonstrating that some, if not all of the new mutations reported here represent likely drivers or modifiers of myeloproliferative disease.This publication has 30 references indexed in Scilit:
- Orientation-specific signalling by thrombopoietin receptor dimersThe EMBO Journal, 2011
- Thrombopoietin receptor activation: transmembrane helix dimerization, rotation, and allosteric modulationThe FASEB Journal, 2011
- Deep sequencing reveals double mutations in cis of MPL exon 10 in myeloproliferative neoplasmsHaematologica, 2011
- The Asn505 mutation of the c-MPL gene, which causes familial essential thrombocythemia, induces autonomous homodimerization of the c-Mpl protein due to strong amino acid polarityBlood, 2009
- Evidence for a founder effect of the MPL-S505N mutation in eight Italian pedigrees with hereditary thrombocythemiaHaematologica, 2009
- Activating mutations in human acute megakaryoblastic leukemiaBlood, 2008
- Markers of Myeloproliferative Diseases in Childhood Polycythemia Vera and Essential ThrombocythemiaJournal of Clinical Oncology, 2007
- MPLW515L Is a Novel Somatic Activating Mutation in Myelofibrosis with Myeloid MetaplasiaPLoS Medicine, 2006
- An amphipathic motif at the transmembrane-cytoplasmic junction prevents autonomous activation of the thrombopoietin receptorBlood, 2006
- Familial essential thrombocythemia associated with a dominant-positive activating mutation of the c-MPL gene, which encodes for the receptor for thrombopoietinBlood, 2004