| Project/Area Number |
17570162
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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 |
Cell biology
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| Research Institution | The University of Tokushima |
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Principal Investigator |
HORIO Tetsuya The University of Tokushima, Institute of Health Biosciences, Lecturer, 大学院ヘルスバイオサイエンス研究部, 講師 (50222279)
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| Co-Investigator(Kenkyū-buntansha) |
AKASHI Tomohiro Nagoya University, Graduate School of Medicine, Research Associate, 大学院医学系研究科, 助手 (00222513)
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| Project Period (FY) |
2005 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2006: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2005: ¥2,400,000 (Direct Cost: ¥2,400,000)
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| Keywords | polar growth / filamentous fungus / microtubule / actin / live cell observation / fluorescent labeling / real time |
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| Research Abstract |
Tip growth of filamentous fungus is one of typical instances of polar growth that is ubiquitously observed throughout species. We previously identified tip-region specific cytoplasmic microtubule regulation that could be important for rapid and continuous tip growth.
1. Role of actin in tip growth: Actin is essential for all kinds of cell expansion. By observing an actin-GFP expressing strain, we identified that actin localized in subapical region as bunch of patches. Localization of these actin patches was microtubule-dependent. Tip growth was immediately inhibited by inhibition of actin polymerization and actin patches gradually deformed and dislocalized from subapical region over a relatively long period of time.
2. Dynamic behavior of SNARE proteins : SNAREs are a group of proteins that promote vesicular fusion and considered to be essential for expansion of cell volume. We observed GFP-labeled transfer (t-) SNARE and vesicular (v-) SNARE and found that the latter localized predominantly at the tip while the former distributed throughout the plasmamembrane rather evenly. By dual observation of the v-SNARE and an actin-binding protein, we found the localization of the v-SNARE is limited from the tip of the cell to the site of actin patches.
3. Whole genome analysis of kinesins : There are 11 kinesins in A. nidulans genome. We replaced the promoters of 9 of kinesin genes with inducible AlcA promoter. All of kinesins tested were not essential nor lethal when overexpressed. However, change of expression level of some of these kinesins affected to the growth rate and morphology. We constructed strains expressing C-terminus mCherry labeled kinesins using all 11 kinesin genes. Nine of these strains gave detectable signal and localization of the signal could be classified following three classes; tip localization, nuclear localization and random dot-like signals without particular site of accumulation.
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