| Project/Area Number |
09670156
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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 |
Pathological medical chemistry
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| Research Institution | Yamaguchi University |
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Principal Investigator |
KISHI Fumio Yamaguchi University, Center for Gene Research, Associate Professor, 遺伝子実験施設, 助教授 (40153077)
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| Co-Investigator(Kenkyū-buntansha) |
岸 文雄 山口大学, 遺伝子実験施設, 助教授 (40153077)
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| Project Period (FY) |
1997 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 1999: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1998: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1997: ¥2,000,000 (Direct Cost: ¥2,000,000)
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| Keywords | natural resistance / NRAMP / phagocytosis |
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| Research Abstract |
The Bcg/Ity/Lsh locus in the mouse genome regulates macrophage activation for antimicrobial activity against intracellular pathogens, and the positional cloning of this locus indentified the Nramp1 (natural resistance-associated macrophage protein) gene. Nramp2 was initially isolated as a homologue of Nramp1. In the present study, a full length cDNA for human NRAMP2 has been isolated and characterized, and we report the complete structure of the human NRAMP2 gene. The promoter was located between-246 bp to 145 bp in a region relative to the transcription start site. A polymorphic dinucleotide repeat was found in the third intron of the NRAMP2 gene. This polymorphism will be a useful genetic marker to study disease associated with susceptibility to infection with intracellular pathogens.
To investigate the biological activity of NRAMP molecules, we constructed four chimeric NRAMP gene by swapping the domains of human NRAMP1 and NRAMP2 with each other. The functional characterisitics of wild-type NRAMP1, NRAMP2 and their chimeras were determined by expression in the disruptant of fission yeast NRAMP-homologue, pdt1D, and we analyzed the complementation activity of EGTA- and pH-sensitive phenotype of pdt1D, Replacement of the N-terminal cytoplasmic domain of NRAMP2 with the NRAMP1 counterpart resulted in inactive chimeras, indicating that the functional difference between NRAMP1 and NRAMP2 is located in this region.
It was found that the NRAMP1 molecule was associated with microtubules. These results suggest that NRAMP1 may function as a molecule having the abilities of membrane-anchoring and microtubule-binding for the microtubule-mediated transport of vesicles and be a new class of microtubule-associated proteins. In contrast, no microtubule-binding activity was probed in the counter part of the NRAMP2 molecule.
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