1997 Fiscal Year Final Research Report Summary
Transcription factors regulating the erytnroid and megakaryocytic cell differentiation.
| Project/Area Number |
08670162
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Pathological medical chemistry
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| Research Institution | University of Tsukuba (1997)
Tohoku University (1996) |
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Principal Investigator |
MINEGISHI Naoko University of Tsukuba, Institute of Basic Medicine, Lecturer, 基礎医学系, 講師 (40271895)
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| Co-Investigator(Kenkyū-buntansha) |
YAMAMOTO Masayuki University of Tsukuba, Institute of Basic Medicine, Professor, 基礎医学系, 教授 (50166823)
HAYASHI Norio Tohoku University, School of Medicine, Professor, 医学部, 教授 (00004606)
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| Project Period (FY) |
1996 – 1997
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| Keywords | GATA-2 / GATA-1 / NF-E2p45 / megakaryoyte / erythrocyte / hematopoietic stem cell / erythropoietin / thrombopoetin |
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| Research Abstract |
In the erythroid and megakaryocytic lineage cells, GATA-1 and GATA-2 show overlapping expression. The gene targeting experiments demonstrate that GATA-2 is essential for the hematopoietic stem and progenitor cells while GATA-1 expression is required for the terminal differentiation of both erythrocytes and megakaryocytes. We investigated the gene expression of GATA factors on leukemic cells and the transcriptional regulation of GATA-2 gene. The results are as follows ;
1), GATA-1 and GATA-2 were expressed concomitantly on the leukemic cells with megakaryocytic or erythroid surface markers. GATA-2 mRNA was also detected in the myelogenous leukemia cells without any megakaryocytic or erythroid features. GATA-2 expression in leukemic cells were correlated with the c-kit antigen expression. This finding was consistent with the reports that GATA-2 has distinct functions in hematopoietic stem/progenitor cells.
2), Transcription of mouse GATA-2 gene was found to initiate from two distinct first
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exons, both of which encode entirely untranslated regions, while the remaining five exons are shared by each of the two divergent mRNAs. Reverse transcriptase-polymerase chain reaction analysis revealed that GATA-2 mRNA initiated at the upstream first exon (IS) in Sca-1+/c-kit+hematopoieticprogenitor cells, whereas mRNA initiated at the downstream first exon (IG) is expressed in all tissues and cell lines that express GATA-2. While the structure of the IG exon/promoter shows high similarity to those of the Xenopus and human GATA-2 gene, the IS exon/promoter has not been described previously. Sequences lying between-79 and -61 are found to be critical for the cell type-specific activity of the IS promoter, and the binding of transcription factors to this region were demonstrated.
3), A transgene containing the IS promoter and 6 kbp upstream region diercted expression of a reporter gene recapitulated the GATA-2 expression in aorta-gonads-mesonephros region and in bone marrow cells. Deletion analysis of the upstream region of IS promoter localized a hematopoietic enhancer activity between 3.5 to 2.5 kbp upstream of the IS exon. This region contained one of the DNaseI hypersensitve sites. Less
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