Granath K, Modig T, Forsmark A, Adler L, Lidén G
Department of Cell and Molecular Biology--Microbiology, Göteborg University, Box 462, SE-405 30 Göteborg, Sweden.
Yeast. 2005 Dec;22(16):1257-68. doi: 10.1002/yea.1307.
Under anaerobic conditions S. cerevisiae produces glycerol to regenerate NAD(+) from the excess NADH produced in cell metabolism. We here report on the role of an uncharacterized protein, Yig1p (Ypl201cp), in anaerobic glycerol production. Yig1p was previously shown to interact in two-hybrid tests with the GPP1 and GPP2 encoded glycerol 3-phosphatase (Gpp), and we here demonstrate that strains overexpressing YIG1 show strongly decreased Gpp activity and content of the major phosphatase, Gpp1p. However, cells overexpressing YIG1 exhibited only slightly decreased GPP1 transcript levels, suggesting that Yig1p modulates expression on both transcriptional and post-transcriptional levels. In agreement with such a role, a GFP-tagged derivate of Yig1p was localized to both the cytosol and the nucleus. Deletion or overexpression of YIG1 did not, however, significantly affect growth yield or glycerol yield in anaerobic batch cultures, which is consistent with the previously proposed low flux control exerted at the Gpp level.
在厌氧条件下，酿酒酵母通过产生甘油，从细胞代谢过程中产生的过量还原型辅酶I（NADH）再生氧化型辅酶I（NAD⁺）。我们在此报告一种未鉴定的蛋白质Yig1p（Ypl201cp）在厌氧甘油生产中的作用。之前在双杂交试验中发现Yig1p与由GPP1和GPP2编码的甘油3 - 磷酸酶（Gpp）相互作用，我们在此证明过表达YIG1的菌株显示出Gpp活性以及主要磷酸酶Gpp1p的含量大幅降低。然而，过表达YIG1的细胞仅表现出GPP1转录水平略有下降，这表明Yig1p在转录和转录后水平上调节表达。与此作用一致，Yig1p的绿色荧光蛋白（GFP）标记衍生物定位于细胞质和细胞核。然而，YIG1的缺失或过表达在厌氧分批培养中并未显著影响生长产量或甘油产量，这与之前提出的Gpp水平低通量控制一致。
