| Project/Area Number |
63480127
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
General medical chemistry
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| Research Institution | Yamaguchi University |
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Principal Investigator |
NAKAZAWA Atsushi Yamaguchi Univ.Sch, Med. Prof., 医学部, 教授 (90025594)
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| Co-Investigator(Kenkyū-buntansha) |
YAMADA Mamoru Yamaguchi Univ.Sch.Med. Res.Ass., 医学部, 助手 (30174741)
INOUYE Sachiye Yamaguchi Univ.Sch.Med. Res.Ass., 医学部, 助手 (60159978)
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| Project Period (FY) |
1988 – 1989
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| Project Status |
Completed (Fiscal Year 1989)
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| Budget Amount *help |
¥4,200,000 (Direct Cost: ¥4,200,000)
Fiscal Year 1989: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 1988: ¥2,800,000 (Direct Cost: ¥2,800,000)
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| Keywords | Adenylate kinase / Isozymes / cDNA / Metabolic control / Mitochondrial localization / アデニレートキナーゼ / 高温致死変異 |
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| Research Abstract |
Adenylate kinase contributes to homeostasis of the cellular adenine nucleotide composition. Three isozymes have been identified: the cytosol type-AK1, the mitochondrial intermembraneous-type AK2, and the mitochondrial matrix type-AK3. However, the physiological significance of such different subcellular distribution remains to be solved.
This study aims at the analysis of the effect of changes in the subcellular distribution of the enzymes on the cellular metabolism after introduction and expression of cDNAs for adenylate kinase isozymes. To control the subcellular distribution of the enzymes, knowledge on the targeting signal to cellular compartments especially to mitochondria is essential. This study established that the AK3 molecule has no cleavable N-terminal sequence as found in other mitochondrial proteins. When the AK3 cDNA was expressed in Escherichia coli, the AK3 protein was exported to the periplasmic space through the bacterial inner membrane. An expression plasmid was constructed which directs a fusion protein consisting of the N-terminal portion of AK3 (residues 6 - 23) and beta- lactamase. When this plasmid was expressed in E. coli, the fusion protein was recovered in the periplasm. These results indicate that the involvement of the N-terminal sequence of AK3 in targeting to the mitochondrial matrix.
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