The Ets transcription factor PU.1 is essential for inducing the differentiation of monocytes, macrophages, and B cells in fetal liver and adult bone marrow. PU.1 controls hematopoietic differentiation through physical interactions with other transcription factors, such as C/EBPα and the AP-1 family member c-Jun. We found that PU.1 recruits c-Jun to promoters without the AP-1 binding sites. To address the functional importance of this interaction, we generated PU.1 point mutants that do not bind c-Jun while maintaining normal DNA binding affinity. These mutants lost the ability to transactivate a target reporter that requires a physical PU.1-c-Jun interaction, and did not induce monocyte/macrophage differentiation of PU.1-deficient cells. Knock-in mice carrying these point mutations displayed an almost complete block in hematopoiesis and perinatal lethality. While the PU.1 mutants were expressed in hematopoietic stem and early progenitor cells, myeloid differentiation was severely blocked, leading to an almost complete loss of mature hematopoietic cells. Differentiation into mature macrophages could be restored by expressing PU.1 mutant fused to c-Jun, demonstrating that a physical PU.1-c-Jun interaction is crucial for the transactivation of PU.1 target genes required for myeloid commitment and normal PU.1 function in vivo during macrophage differentiation.

• MeSH
• buněčná diferenciace genetika   MeSH
• hematopoéza * genetika   MeSH
• myši MeSH
• promotorové oblasti (genetika) MeSH
• protoonkogenní proteiny c-jun MeSH
• transkripční faktor AP-1 * genetika   MeSH
• vazebná místa MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• protoonkogenní proteiny c-jun MeSH
• transkripční faktor AP-1 * MeSH

GATA-1 and PU.1 are two important hematopoietic transcription factors that mutually inhibit each other in progenitor cells to guide entrance into the erythroid or myeloid lineage, respectively. PU.1 controls its own expression during myelopoiesis by binding to the distal URE enhancer, whose deletion leads to acute myeloid leukemia (AML). We herein present evidence that GATA-1 binds to the PU.1 gene and inhibits its expression in human AML-erythroleukemias (EL). Furthermore, GATA-1 together with DNA methyl Transferase I (DNMT1) mediate repression of the PU.1 gene through the URE. Repression of the PU.1 gene involves both DNA methylation at the URE and its histone H3 lysine-K9 methylation and deacetylation as well as the H3K27 methylation at additional DNA elements and the promoter. The GATA-1-mediated inhibition of PU.1 gene transcription in human AML-EL mediated through the URE represents important mechanism that contributes to PU.1 downregulation and leukemogenesis that is sensitive to DNA demethylation therapy.

• MeSH
• akutní erytroblastická leukemie genetika   patologie   MeSH
• akutní myeloidní leukemie genetika   patologie   MeSH
• buněčná diferenciace genetika   MeSH
• DNA-(cytosin-5-)methyltransferasa genetika   metabolismus   MeSH
• DNA-(cytosin-5)-methyltransferasa 1 MeSH
• genetická transkripce MeSH
• histony genetika   MeSH
• lidé MeSH
• metylace DNA genetika   MeSH
• promotorové oblasti (genetika) MeSH
• protoonkogenní proteiny biosyntéza   genetika   metabolismus   MeSH
• regulace genové exprese u leukemie MeSH
• trans-aktivátory biosyntéza   genetika   metabolismus   MeSH
• transkripční faktor GATA1 genetika   metabolismus   MeSH
• vazba proteinů MeSH
• zesilovače transkripce MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• DNA-(cytosin-5-)methyltransferasa MeSH
• DNA-(cytosin-5)-methyltransferasa 1 MeSH
• DNMT1 protein, human MeSH Prohlížeč
• GATA1 protein, human MeSH Prohlížeč
• histony MeSH
• proto-oncogene protein Spi-1 MeSH Prohlížeč
• protoonkogenní proteiny MeSH
• trans-aktivátory MeSH
• transkripční faktor GATA1 MeSH

CCCTC-binding factor (CTCF) can both activate as well as inhibit transcription by forming chromatin loops between regulatory regions and promoters. In this regard, Ctcf binding on non-methylated DNA and its interaction with the Cohesin complex results in differential regulation of the H19/Igf2 locus. Similarly, a role for CTCF has been established in normal hematopoietic development; however its involvement in leukemia remains elusive. Here, we show that Ctcf binds to the imprinting control region of H19/Igf2 in AML blasts. We also demonstrate that Smarca5, which also associates with the Cohesin complex, facilitates Ctcf binding to its target sites on DNA. Furthermore, Smarca5 supports Ctcf functionally and is needed for enhancer-blocking effect at ICR. We next asked whether CTCF and SMARCA5 control the expression of key hematopoiesis regulators. In normally differentiating myeloid cells both CTCF and SMARCA5 together with members of the Cohesin complex are recruited to the SPI1 gene, a key hematopoiesis regulator and leukemia suppressor. Due to DNA methylation, CTCF binding to the SPI1 gene is blocked in AML blasts. Upon AZA-mediated DNA demethylation of human AML blasts, CTCF and SMARCA5 are recruited to the -14.4 Enhancer of SPI1 gene and block its expression. Our data provide new insight into complex SPI1 gene regulation now involving additional key epigenetic factors, CTCF and SMARCA5 that control PU.1 expression at the -14.4 Enhancer.

• MeSH
• adenosintrifosfatasy genetika   metabolismus   MeSH
• akutní erytroblastická leukemie genetika   metabolismus   patologie   MeSH
• akutní nemoc MeSH
• azacytidin farmakologie   MeSH
• buňky K562 MeSH
• CCCTC-vazebný faktor MeSH
• chromozomální proteiny, nehistonové genetika   metabolismus   MeSH
• epigeneze genetická * MeSH
• genomový imprinting MeSH
• HeLa buňky MeSH
• imunoblotting MeSH
• insulinu podobný růstový faktor II genetika   metabolismus   MeSH
• konfokální mikroskopie MeSH
• lidé MeSH
• metylace DNA účinky léků   MeSH
• myeloidní leukemie genetika   metabolismus   patologie   MeSH
• nádorové buněčné linie MeSH
• polymerázová řetězová reakce s reverzní transkripcí MeSH
• protoonkogenní proteiny genetika   metabolismus   MeSH
• regulace genové exprese u nádorů MeSH
• represorové proteiny genetika   metabolismus   MeSH
• RNA dlouhá nekódující genetika   metabolismus   MeSH
• RNA interference MeSH
• trans-aktivátory genetika   metabolismus   MeSH
• vazba proteinů MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• adenosintrifosfatasy MeSH
• azacytidin MeSH
• CCCTC-vazebný faktor MeSH
• chromozomální proteiny, nehistonové MeSH
• CTCF protein, human MeSH Prohlížeč
• H19 long non-coding RNA MeSH Prohlížeč
• insulinu podobný růstový faktor II MeSH
• proto-oncogene protein Spi-1 MeSH Prohlížeč
• protoonkogenní proteiny MeSH
• represorové proteiny MeSH
• RNA dlouhá nekódující MeSH
• SMARCA5 protein, human MeSH Prohlížeč
• trans-aktivátory MeSH