1996 Fiscal Year Final Research Report Summary
Characteristics of ion tranport systems in Vibrio parahaemolyticus and Staphylococcus aureus
| Project/Area Number |
07672358
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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 |
Biological pharmacy
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| Research Institution | Okayama University |
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Principal Investigator |
TSUCHIYA Tomofusa Okayama University, Faculty of Pharmaceutical Sciences, Professor, 薬学部, 教授 (80012673)
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| Co-Investigator(Kenkyū-buntansha) |
SHIMAMOTO Tadashi Okayama University, Gene Research Center, Research Associate, 遺伝子実験施設, 助手 (90187443)
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| Project Period (FY) |
1995 – 1996
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| Keywords | Vibro parahaemolyticus / Staphylococcus aureus / Na^+ transport system / halotorelance / antiporter / ion transport system |
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| Research Abstract |
Vabrio parahaemolyticus and Staphylococcus aureus are two major causes of food poisoning in Japan. S.aureus is also a major cause of infection in hospitals. The former requires Na^+ for its growth, and the latter is a Na^+-torelant microorganism. Base on these characteristics, we investigated ion transport systems, especially Na^+ transport systems, in these microorganisms. We biochemically and molecular biologically characterized such transport systems, and investigated relationship between halophilicity or halotorelance of these bacteria and Na^+ transport.
We characterized the Na^+/H^+ antiporter in V.parahaemolyticus and cloned gene for the antiporter. We thereafter sequenced the gene and revealed the primary structure of the antiporter. We found sequence similarity between the Na^+/H^+ antiporter and the NhaB Na^+/H^+ antiporter of Escherichia coli. Thus, we designated the antiporter of V.parahaemolyticus as NhaB.We identified several functional amino acid residues of the Na^+/H^+ antiporters. We also found the third Na^+/H^+ antiporter NhaD and characterized it. The gene was cloned and sequenced. We found that it was a new type of Na^+/H^+ antiporter. It became claer that the Na^+/H^+ antiporters are very important for halophilicity and halotorelance. The Na^+/glucose symporter (SglS) was also characterized. We cloned the structural gene and sequenced it. We found sequence similarity between the SglS and human SGLT,Na^+/glucose symporter.
We developed a method for the preparation of everted membrane vesicles of S.aureus. We found that Na^+/H^+ antiporter is present in this microorganism. We characterized it, cloned the structural genes and sequenced them. This Na^+/H^+ antiporter was revelaed to be a novel type of antiporter. We found that this antiporter is involved in halotorelance and intracellular pH regulation.
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