title: Transgenic rescue of GATA-1-deficient mice with GATA-1 lacking a FOG-1 association site phenocopies patients with X-linked thrombocytopenia.
abstract: Association of GATA-1 and its cofactor Friend of GATA-1 (FOG-1) is essential for erythroid and megakaryocyte development. To assess functions of GATA-1-FOG-1 association during mouse development, we used the GATA-1 hematopoietic regulatory domain to generate transgenic mouse lines expressing a mutant GATA-1, which contains a substitution of glycine 205 for valine (V205G) that abrogates its association with FOG-1. We examined whether the transgenic expression of mutant GATA-1 rescues GATA-1 germ line mutants from embryonic lethality. In high-expressor lines we observed that the GATA-1(V205G) rescues GATA-1-deficient mice from embryonic lethality at the expected frequency, revealing that excess GATA-1(V205G) can eliminate the lethal anemia that is due to GATA-1 deficiency. In contrast, transgene expression comparable to the endogenous GATA-1 level resulted in much lower frequency of rescue, indicating that the GATA-1-FOG-1 association is critical for normal embryonic hematopoiesis. Rescued mice in these analyses exhibit thrombocytopenia and display dysregulated proliferation and impaired cytoplasmic maturation of megakaryocytes. Although anemia is not observed under steady-state conditions, stress erythropoiesis is attenuated in the rescued mice. Our findings reveal an indispensable role for the association of GATA-1 and FOG-1 during late-stage megakaryopoiesis and provide a unique model for X-linked thrombocytopenia with inherited GATA-1 mutation.
authors.affiliation: Center for Tsukuba Advanced Research Alliance, University of Tsukuba, Tsukuba, Japan.
authors.forename: Ritsuko
authors.initials: R
authors.lastname: Shimizu
authors.forename: Kinuko
authors.initials: K
authors.lastname: Ohneda
authors.forename: James Douglas
authors.initials: JD
authors.lastname: Engel
authors.forename: Cecelia D
authors.initials: CD
authors.lastname: Trainor
authors.forename: Masayuki
authors.initials: M
authors.lastname: Yamamoto
mesh_terms: D019943:Amino Acid Substitution; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D001854:Bone Marrow Cells / Q000166:cytology; D002352:Carrier Proteins / Q000378:metabolism*; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics; D003114:Colony-Forming Units Assay; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000172:deficiency / Q000235:genetics* / Q000378:metabolism; D050981:Erythroid-Specific DNA-Binding Factors; D005434:Flow Cytometry; D050982:GATA1 Transcription Factor; D017930:Genes, Reporter; D018095:Germ-Line Mutation; D006801:Humans; D051379:Mice; D018345:Mice, Knockout; D008822:Mice, Transgenic; D009687:Nuclear Proteins / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013921:Thrombocytopenia / Q000235:genetics*; D014157:Transcription Factors / Q000172:deficiency / Q000235:genetics* / Q000378:metabolism; D014960:X Chromosome
chemical_list: D002352:Carrier Proteins; D017931:DNA Primers; D004268:DNA-Binding Proteins; D050981:Erythroid-Specific DNA-Binding Factors; D050982:GATA1 Transcription Factor; C494688:GATA1 protein, human; C494689:Gata1 protein, mouse; D009687:Nuclear Proteins; D014157:Transcription Factors; C498432:ZFPM1 protein, human; C107310:Zfpm1 protein, mouse; D015500:Chloramphenicol O-Acetyltransferase