1987 Fiscal Year Final Research Report Summary
Studies on the formation of organelles (peroxisomes) in yeast
| Project/Area Number |
61550723
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
発酵工学
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| Research Institution | Kyoto University |
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Principal Investigator |
TANAKA Atsuo Kyoto Univ. Fac. of Eng., Professor, 工学部, 教授 (80026088)
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| Co-Investigator(Kenkyū-buntansha) |
SONOMOTO Kenji Kyoto Univ. Fac. of Eng., Instructor, 工学部, 助手 (10154717)
UEDA Mitsuyoshi Kyoto Un 京都大学, 工学部, 助手 (90183201)
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| Project Period (FY) |
1986 – 1987
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| Keywords | n-Alkane-utilizable yeast / Candida tropicalis pK 233 / Peroxisomes / Fatty acid <beta>-oxidation system / Bifunctional enzyme / Domain of enoly-CoA hydratese / Genomic DNA sequence for the peroxisomal catalase / 局在化 |
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| Research Abstract |
Candida tropicalis pK 233, an n-alkane-utilizable yeast, is an excellent microorganism for studying the localization of specific peroxisomal enzymes in connection with the development of the organelles since development and degradation of peroxisomes as well as the induction and repression of peroxisomal enzymes can be easily controlled by changing the carbon source for growth.
1. Development of the mature peroxisomes was observed during the assimilation of n-alkanes by the yeast. We succeeded in the isolation of the pre-existing peroxisomes from glucose-grown cells and the immature ones from propionate-grown cells as well as the mature ones from alkane-grown cells, and examined their biochemical and cytological properties. The pre-existing peroxisomes form the yeast cells were found to be glyoxysome-like organelles having the key enzymes of glyoxylate cycle.
2. A protein exhibiting only enoyl-CoA hydratase activity was purified from the whole cells of n-alkane-grown cells. On the other hand, a bifunctional enzyme exhibiting enoyl-CoA hydratase and 3-hydroxyacyl-CoA dehydrogenase activities was obtaind from the same yeast cells when purified in the presence of protease inhibitors. Limited proteolysis of the bifunctional enzyme with <alpha>-chymotrypsin indicated that the former was a part of the bifunctional enzyme. The fact strongly suggests that the domain of enoly-CoA hydratese is separable from the bifunctional enzyme and is noticeable on the evolution of fatty acid <beta>-oxidation system.
3. A clone harbouring the genomic DNA sequence for the peroxisomal catalase has been isolated using the catalase cDNA as a probe, which had been obtained with the antibody-screening method. Analysis of the nucleotide sequence and the deduced amino acid sequence revealed the presence of a noticeable region responsible to the specific localization of catalase into peroxisomes.
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