| Project/Area Number |
14580652
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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 |
Functional biochemistry
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| Research Institution | Teikyo University |
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Principal Investigator |
KASAHARA Michihiro Teikyo University, School of Medicine, Professor, 医学部, 教授 (40010102)
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| Co-Investigator(Kenkyū-buntansha) |
KASAHARA Toshiko Teikyo University, School of Medicine, Lecturer, 医学部, 講師 (60328086)
豊福 恭子 帝京大学, 医学部, 博士研究員
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| Project Period (FY) |
2002 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2003: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 2002: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | Glucose transporter / Chimera / Substrate recognition / Yeast / GLUT / Hxt2 |
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| Research Abstract |
The yeast Saccharomyces cerevisiae possesses 18 hexose transporters (Hxtl-17, Gal2). They contain 12 transmembrane segments (TMs), and belong to the major facilitator superfamily that is the major transport family for organic solutes. Chimeras were constructed by randomly replacing each of the L2TMs of Hxt2, a high affinity glucose transporter with the corresponding segment of Hxt1, a low affinity glucose transporter (TM shuffling). Characterization of these chimeras revealed that at least TMs 1, 5, 7 and 8 of Hxt2 are required for high-affinity glucose transport activity.
To determine which amino acid residues in these 4 TMs are important for high-affinity glucose transport, we comprehensively shuffled all the 20 residues in these regions that differ between Hxt2 and Hxt1. Analysis of 60 independent chimera strains identified as expressing high-affinity and high-capacity glucose transport by the selection on glucose-limited agar plates revealed that Leu-201 in TM5 of Hxt2 is most important. Simulation by molecular dynamics indicated that Leu-201 is situated at the wall of aqueous pore constructed by several TMs including This 1, 5, 7, and 8.
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