title: Cross talk between retinoic acid signaling and transcription factor GATA-2.
abstract: All-trans-retinoic acid (RA) stimulates differentiation of normal hematopoietic progenitors and acute myeloid leukemia cells. GATA-2 is a transcription factor expressed in early progenitor cells and implicated in the control of the fate of hematopoietic stem cells and progenitor cells. We have investigated the possibility that the GATA and nuclear hormone receptor pathways are functionally linked through direct protein-protein interaction. Here we demonstrate that in human myeloid KG1 cells, RA receptor alpha (RARalpha), the major RAR expressed in hematopoietic cells, associates with GATA-2. This association is mediated by the zinc fingers of GATA-2 and the DNA-binding domain of RARalpha. As a consequence of this interaction, RARalpha is tethered to the DNA sites that are recognized and bound by GATA-2, and the transcriptional activity of GATA-2 becomes RA responsive. The RA responsiveness of GATA-dependent transcription is eliminated by expression of either a dominant negative form of RARalpha or a GATA-2 mutant that fails to interact with RARalpha. Overexpression of RXRalpha inhibits RARalpha binding to the GATA-2-DNA complex, thus resulting in attenuation of the effects of RARalpha on GATA-2 activity. In addition, inhibition by RA of GATA-2-dependent hematopoietic colony formation in an embryonic stem cell model of hematopoietic differentiation provided biological evidence for functional cross talk between RA and GATA-2-dependent pathways.
authors.affiliation: Section of Gene Function and Regulation, Institute of Cancer Research, London SW3 6JB, UK.
authors.forename: Shinobu
authors.initials: S
authors.lastname: Tsuzuki
authors.forename: Kenji
authors.initials: K
authors.lastname: Kitajima
authors.forename: Toru
authors.initials: T
authors.lastname: Nakano
authors.forename: Annegret
authors.initials: A
authors.lastname: Glasow
authors.forename: Arthur
authors.initials: A
authors.lastname: Zelent
authors.forename: Tariq
authors.initials: T
authors.lastname: Enver
mesh_terms: D020816:Amino Acid Motifs; D000818:Animals; D015153:Blotting, Western; D002454:Cell Differentiation; D002460:Cell Line; D045744:Cell Line, Tumor; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D050989:GATA2 Transcription Factor; D005822:Genetic Vectors; D006412:Hematopoietic Stem Cells / Q000378:metabolism; D006801:Humans; D008156:Luciferases / Q000378:metabolism; D051379:Mice; D008957:Models, Genetic; D009154:Mutation; D010957:Plasmids / Q000378:metabolism; D011233:Precipitin Tests; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D018168:Receptors, Retinoic Acid / Q000378:metabolism; D047488:Retinoid X Receptors; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D013997:Time Factors; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014162:Transfection; D014212:Tretinoin / Q000378:metabolism*; D020798:Two-Hybrid System Techniques
chemical_list: D004268:DNA-Binding Proteins; D050989:GATA2 Transcription Factor; C494711:GATA2 protein, human; C494712:Gata2 protein, mouse; D018168:Receptors, Retinoic Acid; D047488:Retinoid X Receptors; D014157:Transcription Factors; D014212:Tretinoin; D004247:DNA; D008156:Luciferases