Differential contribution of the proline and glutamine pathways to glutamate biosynthesis and nitrogen assimilation in yeast lacking glutamate dehydrogenase.
Differential contribution of the proline and glutamine pathways to glutamate biosynthesis and nitrogen assimilation in yeast lacking glutamate dehydrogenase.
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DOI：
10.1016/j.micres.2014.02.004
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发表时间：
2014-09
影响因子：
6.7
通讯作者：
Trotter, Pamela J.
中科院分区：
文献类型：
--
作者：
Sieg, Alex G.;Trotter, Pamela J.
在酿酒酵母中，谷氨酸脱氢酶 (GDH) 在谷氨酸生物合成和氮同化中发挥着关键作用。有人提出，在 GDH 缺陷的酵母中，脯氨酸利用 (PUT) 或谷氨酰胺合成酶-谷氨酸合酶 (GS/GOGAT) 途径可作为谷氨酸生产和氮同化的替代途径，而排除另一途径。使用 gdh-null 突变体 (gdh1Δ2Δ3Δ)，结合生长研究和对各种氮源（氨、谷氨酰胺、脯氨酸和尿素）的途径特异性酶测定，解决了这种模糊性。 GDH 缺失突变体在所有测试的氮源上均能存活，这证实了 GDH 缺失菌株中存在氮同化的替代途径。酶测定表明 GS/GOGAT 是首选氮源氨和谷氨酰胺的主要替代途径，而脯氨酸的生长则需要 PUT 和 GS/GOGAT 途径。相反，在葡萄糖-尿素培养基上生长引起GOGAT活性降低，同时PUT途径特异性酶Δ1-吡咯啉-5-羧酸脱氢酶(P5CDH)活性增加。总之，这些结果表明，缺乏首选 GDH 依赖性途径的菌株中氮同化的替代途径是氮源依赖性的，并且 GS/GOGAT 和 PUT 都不是唯一的补偿途径。
In Saccharomyces cerevisiae, the glutamate dehydrogenase (GDH) enzymes play a pivotal role in glutamate biosynthesis and nitrogen assimilation. It has been proposed that, in GDH-deficient yeast, either the proline utilization (PUT) or the glutamine synthetase-glutamate synthase (GS/GOGAT) pathway serves as the alternative pathway for glutamate production and nitrogen assimilation to the exclusion of the other. Using a gdh-null mutant (gdh1Δ2Δ3Δ), this ambiguity was addressed using a combination of growth studies and pathway-specific enzyme assays on a variety of nitrogen sources (ammonia, glutamine, proline and urea). The GDH-null mutant was viable on all nitrogen sources tested, confirming that alternate pathways for nitrogen assimilation exist in the gdh-null strain. Enzyme assays point to GS/GOGAT as the primary alternative pathway on the preferred nitrogen sources ammonia and glutamine, whereas growth on proline required both the PUT and GS/GOGAT pathways. In contrast, growth on glucose-urea media elicited a decrease in GOGAT activity along with an increase in activity of the PUT pathway specific enzyme Δ1-pyrroline-5-carboxylate dehydrogenase (P5CDH). Together, these results suggest the alternative pathway for nitrogen assimilation in strains lacking the preferred GDH-dependent route is nitrogen source dependent and that neither GS/GOGAT nor PUT serves as the sole compensatory pathway.
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影响因子：
4.8
作者：
DeLuna, A;Avendaño, A;González, A
通讯作者：
González, A
影响因子：
2.6
作者：
HILL, JE;MYERS, AM;TZAGOLOFF, A
通讯作者：
TZAGOLOFF, A
影响因子：
3.2
作者：
Avendano, A;Deluna, A;Gonzalez, A
通讯作者：
Gonzalez, A
DOI：
10.1007/s004380050644
发表时间：
1998-01-01
期刊：
MOLECULAR AND GENERAL GENETICS
影响因子：
--
作者：
Iraqui, I;Vissers, S;Urrestarazu, A
通讯作者：
Urrestarazu, A
影响因子：
3.2
作者：
ROON, RJ;EVEN, HL;LARIMORE, F
通讯作者：
LARIMORE, F