[Show abstract][Hide abstract] ABSTRACT: Heterozygous germline mutations in the zinc finger transcription factor GATA2 have recently been shown to underlie a range of clinical phenotypes, including Emberger syndrome, a disorder characterized by lymphedema and predisposition to myelodysplastic syndrome/acute myeloid leukemia (MDS/AML). Despite well-defined roles in hematopoiesis, the functions of GATA2 in the lymphatic vasculature and the mechanisms by which GATA2 mutations result in lymphedema have not been characterized. Here, we have provided a molecular explanation for lymphedema predisposition in a subset of patients with germline GATA2 mutations. Specifically, we demonstrated that Emberger-associated GATA2 missense mutations result in complete loss of GATA2 function, with respect to the capacity to regulate the transcription of genes that are important for lymphatic vessel valve development. We identified a putative enhancer element upstream of the key lymphatic transcriptional regulator PROX1 that is bound by GATA2, and the transcription factors FOXC2 and NFATC1. Emberger GATA2 missense mutants had a profoundly reduced capacity to bind this element. Conditional Gata2 deletion in mice revealed that GATA2 is required for both development and maintenance of lymphovenous and lymphatic vessel valves. Together, our data unveil essential roles for GATA2 in the lymphatic vasculature and explain why a select catalogue of human GATA2 mutations results in lymphedema.
The Journal of clinical investigation 07/2015; DOI:10.1172/JCI78888 · 13.77 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We report the discovery of GATA2 as a new myelodysplastic syndrome (MDS)-acute myeloid leukemia (AML) predisposition gene. We found the same, previously unidentified heterozygous c.1061C>T (p.Thr354Met) missense mutation in the GATA2 transcription factor gene segregating with the multigenerational transmission of MDS-AML in three families and a GATA2 c.1063_1065delACA (p.Thr355del) mutation at an adjacent codon in a fourth MDS family. The resulting alterations reside within the second zinc finger of GATA2, which mediates DNA-binding and protein-protein interactions. We show differential effects of the mutations on the transactivation of target genes, cellular differentiation, apoptosis and global gene expression. Identification of such predisposing genes to familial forms of MDS and AML is critical for more effective diagnosis and prognosis, counseling, selection of related bone marrow transplant donors and development of therapies.