The protein phosphatase Siw14 controls caffeine-induced nuclear localization and phosphorylation of Gln3 via the type 2A protein phosphatases Pph21 and Pph22 in Saccharomyces cerevisiae.
The protein phosphatase Siw14 controls caffeine-induced nuclear localization and phosphorylation of Gln3 via the type 2A protein phosphatases Pph21 and Pph22 in Saccharomyces cerevisiae.
复制标题
在酿酒酵母中，蛋白磷酸酶 Siw14 通过 2A 型蛋白磷酸酶 Pph21 和 Pph22 控制咖啡因诱导的 Gln3 核定位和磷酸化。
DOI：
10.1093/jb/mvu055
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Harashima S.
中科院分区：
文献类型：
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作者：
Numamoto M;Sasano Y;Hirasaki M;Sugiyama M;Maekawa H;Harashima S.
糖酵母（Saccharomycesae）Siw 14是一种参与咖啡因反应的酪氨酸磷酸酶，参与调节Gln 3的磷酸化和细胞内定位，Gln 3是氮代谢抑制敏感基因的加塔转录激活因子。在Δ siw14细胞中，咖啡因可降低Gln3的磷酸化水平，促进Gln3的核定位。然而，Siw14控制Gln3的定位和功能的机制仍然不清楚，尽管已知Gln3的核定位是由2A型磷酸酶（PP2As）Pph 21和Pph 22以及2A型相关磷酸酶Sit4的激活诱导的。在这项研究中，我们表明，增加核定位的Gln3在响应咖啡因所造成的破坏theSIW14基因是依赖于Sit4和PP2A磷酸酶。我们还发现，由SIW14基因的破坏引起的Gln3磷酸化的降低被PPH21和PPH22的缺失完全抑制，但仅部分被SIT4的缺失抑制。将这些结果结合在一起，我们得出结论，Siw14作为Gln3磷酸化和定位的抑制剂在Pph21和Pph22的上游起作用，并且Sit4独立于Siw14起作用。
TheSaccharomyces cerevisiaeSiw14, a tyrosine phosphatase involved in the response to caffeine, participates in regulation of the phosphorylation and intracellular localization of Gln3, a GATA transcriptional activator of nitrogen catabolite repression-sensitive genes. In Δsiw14cells, the phosphorylation level of Gln3 is decreased and the nuclear localization of Gln3 is stimulated by caffeine. However, the mechanism by which Siw14 controls the localization and function of Gln3 remains unclear, although the nuclear localization of Gln3 is known to be induced by activation of the type 2A phosphatases (PP2As) Pph21 and Pph22, and the type 2A-related phosphatase Sit4. In this study, we show that the increased nuclear localization of Gln3 in response to caffeine caused by disruption of theSIW14gene is dependent on the Sit4 and PP2A phosphatases. We also show that decreased phosphorylation of Gln3 caused by disruption of theSIW14gene is completely suppressed by deletion of bothPPH21andPPH22, but only partially suppressed by deletion ofSIT4. Taking these results together, we conclude that Siw14 functions upstream of Pph21 and Pph22 as an inhibitor of the phosphorylation and localization of Gln3, and that Sit4 acts independently of Siw14.