| Project/Area Number |
16590350
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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 |
Parasitology (including Sanitary zoology)
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| Research Institution | KURUME UNIVERSITY |
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Principal Investigator |
FUKUMA Toshihide Kurume University, Sch.Med., Dept.Parasitol., Professor, 医学部, 教授 (90125146)
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| Co-Investigator(Kenkyū-buntansha) |
INOUE Masahiro Kurume University, Sch.Med., Dept.Parasitol., Associate Professor, 医学部, 助教授 (00232562)
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| Project Period (FY) |
2004 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2005: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 2004: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | Trypanosoma brucei / 14-3-3 / cytokinesis / cell cycle / dimerization / N-terminal / phosphorylation / dophosphorylation / Trypanosoma b. brucei / RNAi / cytekinesis |
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| Research Abstract |
We have previously shown that Trypanosoma brucei 14-3-3 I and II play pivotal roles in motility, cytokinesis and cell cycle (J.Biol.Chem.280, 14085-14096). We here report the unique dimerization pattern of 14-3-3 isoforms ; I forms both heterodimer and homodimer, whereas II forms mainly heterodimer. The α-helices 1-4 are responsible for dimeraization as in the cases of mammalian 14-3-3. In addition, we found unique N-terminal sequences of both isoforms existed in Trypoanosomatidae but not in mammals are indispensable for dimeraization. We further characterized that amino acid ^4Phe, ^6IIe, ^7Pro and ^<13>Leu in the N-terminal sequence of 14-3-3 II are crucial for dimeraization. 14-3-3 proteins act as phoshoserine-dependent molecular chaperones which recognize well-conserved motifs among eukaryotes. However, the precise mechanism by which T.brucei 14-3-3 controls cellular events have yet to be proven. We report that the protein recognition of T.brucei 14-3-3 is different from other eukaryotes ; 1)the surface plasmon resonance analysis reveals that 14-3-3 I but not II possesses weak affinity to the conserved phosphopeptides. 2)14-3-3II interacts with many proteins, not truly phosphorylation-dependent. We further searched how the conserved motifs are utilized, extensively in cultured T.brucei, 3)over expression of the human 14-3-3 isoform but not the mutated form, induces a drastic reduction in a growth rates and morphological changes that are observed in 14-3-3I and/or II knockdown cells, 4)the number of phosphorylated proteins that carry the conserved recognition motifs are small in T.brucei. The new pathway was suggested that phosphorylation would play a roll as so called dephosphorylation in a mirroring fashion.
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