小田 祥久（国立遺伝学研究所 新分野創造センター・准教授）

2019年03月18日(月) 15:00 より 16:30 まで

明大寺地区１階　会議室 (111)

形態形成研究部門　上野 直人（7570）

Cell polarization and patterning are fundamental processes essential for a range of cellular activities. In plant metaxylem vessel cells, pitted cell wall patterns are established at the cell surface to form water-conducting tubes. We have investigated the mechanisms underlying the establishment of the pitted cell wall pattern using various techniques including the originally developed cell culture systems, reconstructive genetics, and theoretical analysis. We demonstrated that, in Arabidopsis, ROP11 Rho GTPase is locally activated to form plasma membrane domains (ROP domains) that induce the disassembly of cortical microtubules through the MIDD1-Kinesin13A complex, resulting in the formation of pits in cell walls [1-3]. We recently found that the ROP activation/inactivation cycle generates ROP domains in a cell-autonomous manner via the reaction-diffusion like mechanism, determining the size and density of pits[4]. We also found that novel microtubule-associated proteins determine the pit shape through regulating the planer shape of ROP domains [5, 6]. In addition, we identified a novel actin-binding protein promoting cell wall deposition specifically at pit boundaries in a ROP-dependent manner [7]. Together, our findings revealed the entire mechanisms by which the domains of ROPs and cytoskeletons are formed, shaped, and matured to develop the pitted cell wall pattern in xylem vessels.

1. Oda et al. (2010) Curr Biol 20, 1197-1202.
2. Oda and Fukuda (2012) Science 337, 1333-1336.
3. Oda and Fukuda (2013) Plant Cell 25, 4439-4450.
4. Nagashima et al. (2018) Scientific reports 8, 11542.
5. Sasaki et al. (2017) Plant Cell 29, 3123-3139.
6. Sugiyama et al. (2017) Curr Biol 27, 2522-2528.
7. Sugiyama et al. (2019) Nat Commun 10, 468.

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