Thrombopoiesis regulated by a transcription factor NF-E2

2006 Fiscal Year Final Research Report Summary

• Project/Area Number: 17390074
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: General medical chemistry
• Research Institution: Tohoku University (2006); University of Tsukuba (2005)
• Principal Investigator: MOTOHASHI Hozumi Tohoku University Graduate School of Medicine, Associate Professor, 大学院医学系研究科, 助教授 (00282351)
• Project Period (FY): 2005 – 2006
• Keywords: NF-E2 / megakaryocytes / platelets / protein complex / microarray / transgenic mice

Research Abstract

The goal of this study was to clarify the regulatory mechanisms of thrombopoiesis through analyzing the function of a heterodimeric transcription factor NF-E2.
1. Structure and function analysis of small Maf
A deletion mutant of MafG that lacks 40 amino acids of its C-terminus did not rescue the defective proplatelet formation of megakaryocytes from mafG-null mice when the mutant MafG was supplied from the transgene. This results clearly showed that the MafG C-terminal region is critical to the small Ma function in megakaryocytes. We investigated the proteins interacting to the MafG C-terminal region through the yeast two hybrid screening. We found that NF-E2 p45 interacts with the full length of MafG but not with MafG without the C-terminus. Interestingly, Nrf2, another member of CNC family transcription factor and a related factor of NF-E2 p45, does interact with MafG irrespective of the presence the C-terminal region. These results imply that MafG C-terminal region may contribute to t he selection of a heterodimeric partner molecule of MafG.
2. Subcellular localization of NF-E2 p45
We established transgenic mouse lines expressing Flag-tagged NF-E2 p45 or GFP-fused NF-E2 p45 in megakaryocytes. We also obtained a stable transformant megakaryocytic cell lines expressing Flag-HA-His tagged NF-E2 p45. By using these mice and cells, we are examining the subcellular distribution of NF-E2 p45.
3. Target genes of NF-E2 p45
We identified a novel gene clone 325 from the subtraction screening of small Maf mutant megakaryocytes and the control megakaryocytes. We disrupted the 325 gene in mice and found that the mice is healthy and fertile displaying the normal platelet count. We are planning to administer anti-platelet antibody and/or myelosupressive reagents to the mice and to see their effects on the thrombopoiesis. We also performed transcriptome analysis of NF-E2 p45-null mice and found that the factors involved in the platelet function and structures are decreased while antioxidant response genes and detoxifying enzyme genes were increased, which suggests the involvement of oxidative stress in the process of megakaryopoiesis and thrombopoiesis.

Research Products

• [Journal Article] Nrf2 Neh5 domain is differentially utilized in the transactivation of cytoprotective genes. (2007)
  • Author(s): Zhang, J., Hosoya, T., Maruyama, A., Nishikawa K., Maher, J.M., Ohta, T., Motohashi, H., Fukamizu, A., Shibahara, S., Itoh, K., Yamamoto, M.
  • Journal Title: Biochem. J. (in press)
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] Carcinogenesis and transcriptional regulation through Maf recognition elements. (2007)
  • Author(s): Motohashi, H., Yamamoto, M.
  • Journal Title: Cancer Sci. 98 Pages: 135-139
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] Nrf2 Neh5 domain is differentially utilized in the transactivation of cytoprotective genes. (2007)
  • Author(s): Zhang, J., Hosoya, T., Maruyama, A., Nishikawa K., Maher, J.M., Ohta, T., Motohashi, H., Fukamizu, A., Shibahara, S., Itoh, K., Yamamoto, M.
  • Journal Title: Biochem.J. (in press)
  • Description: 「研究成果報告書概要(欧文)」より
• [Journal Article] 「研究成果報告書概要(欧文)」より (2007)
  • Author(s): Motohashi, H., Yamamoto, M.
  • Journal Title: Cancer Sci. 98 Pages: 135-139
• [Journal Article] Transgene insertion into the proximity of the c-myb gene disrupts erythroid-megakaryocytic lineage bifurcation. (2006)
  • Author(s): Mukai, H.Y., Motohashi, H., Ohneda, O., Suzuki, N., Nagano, M., Yamamoto, M.
  • Journal Title: Mol. Cell. Biol. 26 Pages: 7953-7965
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] MafG Sumoylation Is Required for Active Transcriptional Repression. (2006)
  • Author(s): Motohashi, H.*, Katsuoka, F., Miyoshi, C., Uchimura Y., Saitoh, H., Francastel, C., Engel, J.D., Yamamoto, M.(* corresponding author)
  • Journal Title: Mol. Cell. Biol. 26 Pages: 4652-4663
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] Predictive base substitution rules that determine the binding and transcriptional specificity of Maf recognition elements. (2006)
  • Author(s): Yamamoto, T., Kyo, M., Kamiya, T., Tanaka, T., Engel, J.D., Motohashi, H.*, Yamamoto, M.
  • Journal Title: Genes Cells 11 Pages: 575-591
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] Hepatocyte-specific deletion of the keapl gene activates Nrf2 and confers potent resistance against acute drug toxicity. (2006)
  • Author(s): Okawa, H., Motohashi, H.*, Kobayashi, A., Aburatani, H., Kensler T.W., Yamamoto, M.
  • Journal Title: Biochem. Biophys. Res. Commun. 339 Pages: 79-88
  • Description: 「研究成果報告書概要(和文)」より
• [Journal Article] Transgene insertion into the proximity of the c-myb gene disrupts erythroid-megakaryocytic lineage bifurcation. (2006)
  • Author(s): Mukai, H.Y., Motohashi, H., Ohneda, 0., Suzuki, N., Nagano, M., Yamamoto, M.
  • Journal Title: Mol.Cell.Biol. 26 Pages: 7953-7965
  • Description: 「研究成果報告書概要(欧文)」より
• [Journal Article] MafG Sumoylation Is Required for Active Transcriptional Repression. (2006)
  • Author(s): Motohashi, H.*, Katsuoka, F., Miyoshi, C., Uchimura Y., Saitoh, H., Francastel, C., Engel, J.D., Yamamoto, M.(* corresponding author)
  • Journal Title: Mol.Cell.Biol. 26 Pages: 4652-4663
  • Description: 「研究成果報告書概要(欧文)」より
• [Journal Article] Predictive base substitution rules that determine the binding and transcriptional specificity of Maf recognition elements. (2006)
  • Author(s): Yamamoto, T., Kyo, M., Kamiya, T., Tanaka, T., Engel, J.D., Motohashi, H.*, Yamamoto, M.(* corresponding author)
  • Journal Title: Genes Cells 11 Pages: 575-591
  • Description: 「研究成果報告書概要(欧文)」より
• [Journal Article] Hepatocyte-specific deletion of the keap1 gene activates Nrf2 and confers potent resistance against acute drug toxicity. (2006)
  • Author(s): Okawa, H., Motohashi, H.*, Kobayashi, A., Aburatani, H., Kensler T.W., Yamamoto, M.(* corresponding author)
  • Journal Title: Biochem.Biophys.Res.Commun. 339 Pages: 79-88
  • Description: 「研究成果報告書概要(欧文)」より