Home ＞GCOE Researchers ＞Yasunori MACHIDA

GCOE Researchers

Yasunori MACHIDA

Affiliation
/Position		 Graduate School of Science, Division of Biological Science, Professor
Doctorate Doctor of Science
Research interests Plant developmental molecular biology, Proliferation and differentiation of plant cells
address yas＠bio.nagoya-u.ac.jp
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+81-52-789-2502
  Laboratory

Outline of research

In the past five years, we have studied signaling systems that control cell division and proliferation of plant cells, and promoted a greater understanding of these controlling factors. Our research has paved the way for a breakthrough discovery of new molecular functions based on these factors.

  1. Molecular mechanism of cytokinesis: We identified direct target proteins of the MAP kinase cascade that controls cytokinesis in plants, and characterized them at the molecular level. Through biochemical and proteomic analyses, we also identified several factors acting downstream of this cascade. We revealed that phosphorylation of MAP65, one of these factors, is essential for cell plate formation (upper panel of left figure). Furthermore, we demonstrated that activation of this MAP kinase cascade is negatively controlled by CDK (Lower panel of the left figure). These results were generated primarily by postdoctoral fellows and graduate students in our laboratory (Sasabe et al., Genes Dev., 2006; and other publications).
  2. Development and differentiation of plant leaves from shoot apical meristem: We demonstrated that both the AS2 gene, which plays an important role in development and differentiation of leaves, and histone deacetylase regulate the production of small RNAs. These results were generated by graduate students in our laboratory (Ueno et al., Plant Cell 2007 and other publications).
  3. Molecular regulation of epidermal cell differentiation: We identified two novel receptor kinases involved in differentiation and maintenance of epidermal cells during embryogenesis of Arabidopsis. In addition, we found several genes whose transcription is controlled downstream of this cascade, and proposed the existence of a new pathway connecting extracellular stimuli to expression of genes required for epidermal differentiation. Also, we developed new techniques to study epidermal cells. These results were mainly generated by graduate students in our laboratory（Tanaka et al., Plant J. 2004 and other publications）.
  4. Action mechanism of plant oncogenes: We clarified subcellular localization and in vitro function of the 6b protein, a tumor formation factor in plant cells, and demonstrated that 6b has activity of histone H3 chaperone, which is essential for cell proliferation. These results were mainly achieved by graduate students in our laboratory（Terakura et al., Plant Cell Physiol. 2006; Terakura et al., Plant Cell revised）。

References

  1. Yang, J.-Y. et al. (2008) bC1, the pathogenicity factor of TYLCCNV, interacts with AS1 to alter leaf development and suppress selective jasmonic acid responses. Genes Dev., 22: 2564-2577.
  2. Ishikawa, T. et al. (2008) The EMBRYO YELLOW gene, encoding a subunit of the conserved oligomeric Golgi complex, is required for appropriate cell expansion and meristem organization in Arabidopsis thaliana. Genes Cells, 13: 521-535.
  3. Terakura, S. et al. (2007) An oncoprotein from the plant pathogen Agrobacterium has histone-chaperone-like activity. Plant Cell, 19: 2855-2865.
  4. Ueno, Y. et al. (2007) Histone deacetylases and ASYMMETRIC LEAVES2 are involved in the establishment of polarity in leaves of Arabidopsis. Plant Cell, 19: 445-457.
  5. Tanaka, H. et al. (2007) Novel receptor-like kinase ALE2 controls shoot development by specifying epidermis in Arabidopsis. Development, 134: 1643-1652.
  6. Sasabe M. et al. (2006) Phosphorylation of NtMAP65-1 by a MAP kinase down-regulates its activity of microtubule bundling and stimulates progression of cytokinesis of tobacco cells. Genes Dev., 20: 1004-1014.
  7. Araki S. et al. (2004) Mitotic cyclins stimulate the activity of c-Myb-like factors for transactivation of G2/M phase-specific genes of tobacco. J. Biol. Chem., 279: 32979 32988.
  8. Tanaka T. et al. (2004) A new method for rapid visualization of defects in leaf cuticle reveals five intrinsic patterns of surface defects in Arabidopsis. Plant J., 37: 139-146.
  9. Asano T. et al. (2004) A mutation of the CRUMPLED LEAF gene that encodes a protein localized in the outer envelope membrane of plastids affects the pattern of cell division, cell differentiation, and plastid division in Arabidopsis. Plant J., 38: 448-459.
  10. Soyano T. et al. (2003) NQK1/NtMEK1 is a MAPKK that acts in the NPK1 MAPKKK-mediated MAPK cascade and is required for plant cytokinesis. Genes Dev.,17: 1055-1067.

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