論文 - 詳細
| RRC ID | 2184 |
|---|---|
| 著者 | Terao Y, Nakamori S, Takagi H. |
| タイトル | Gene dosage effect of L-proline biosynthetic enzymes on L-proline accumulation and freeze tolerance in Saccharomyces cerevisiae. |
| ジャーナル | Appl Environ Microbiol |
| Abstract |
We have previously reported that L-proline has cryoprotective activity in Saccharomyces cerevisiae. A freeze-tolerant mutant with L-proline accumulation was recently shown to carry an allele of the PRO1 gene encoding gamma-glutamyl kinase, which resulted in a single amino acid substitution (Asp154Asn). Interestingly, this mutation enhanced the activities of gamma-glutamyl kinase and gamma-glutamyl phosphate reductase, both of which catalyze the first two steps of L-proline synthesis and which together may form a complex in vivo. Here, we found that the Asp154Asn mutant gamma-glutamyl kinase was more thermostable than the wild-type enzyme, which suggests that this mutation elevated the apparent activities of two enzymes through a stabilization of the complex. We next examined the gene dosage effect of three L-proline biosynthetic enzymes, including Delta(1)-pyrroline-5-carboxylate reductase, which converts Delta(1)-pyrroline-5-carboxylate into L-proline, on L-proline accumulation and freeze tolerance in a non-L-proline-utilizing strain. Overexpression of the wild-type enzymes has no influence on L-proline accumulation, which suggests that the complex is very unstable in nature. However, co-overexpression of the mutant gamma-glutamyl kinase and the wild-type gamma-glutamyl phosphate reductase was effective for L-proline accumulation, probably due to a stabilization of the complex. These results indicate that both enzymes, not Delta(1)-pyrroline-5-carboxylate reductase, are rate-limiting enzymes in yeast cells. A high tolerance for freezing clearly correlated with higher levels of L-proline in yeast cells. Our findings also suggest that, in addition to its cryoprotective activity, intracellular L-proline could protect yeast cells from damage by oxidative stress. The approach described here provides a valuable method for breeding novel yeast strains that are tolerant of both freezing and oxidative stresses. |
| 巻・号 | 69(11) |
| ページ | 6527-32 |
| 公開日 | 2003-11-1 |
| DOI | 10.1128/AEM.69.11.6527-6532.2003 |
| PMID | 14602584 |
| PMC | PMC262311 |
| MeSH | Freezing Gene Dosage* Gene Expression Regulation, Fungal* Heat-Shock Response Molecular Sequence Data Oxidative Stress Phosphotransferases (Carboxyl Group Acceptor) / genetics Proline / biosynthesis* Proline / metabolism Saccharomyces cerevisiae / enzymology* Saccharomyces cerevisiae / genetics Saccharomyces cerevisiae / growth & development Saccharomyces cerevisiae / physiology* Saccharomyces cerevisiae Proteins / genetics Saccharomyces cerevisiae Proteins / metabolism Sequence Analysis, DNA |
| IF | 4.016 |
| 引用数 | 53 |
| WOS 分野 | BIOTECHNOLOGY & APPLIED MICROBIOLOGY MICROBIOLOGY |
| オルトメトリクス指標 |
オルトメトリクス指標項目
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| 最多言及媒体 | Patent(IFI CLAIMS) |
| 各媒体での言及数の合計 | 2 |
| 過去6か月間でのオルトメトリクス指標の変動値 | 0.0 |
| リソース情報 | |
| 酵母 | BYP1804(pCgHIS3) |