Cleavage-Polyadenylation Factor Cft1 and SPX Domain Proteins Are Agents of Inositol Pyrophosphate Toxicosis in Fission Yeast.
Cleavage-Polyadenylation Factor Cft1 and SPX Domain Proteins Are Agents of Inositol Pyrophosphate Toxicosis in Fission Yeast.
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DOI：
10.1128/mbio.03476-21
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发表时间：
2022-02-22
期刊：
影响因子：
6.4
通讯作者：
Shuman S
中科院分区：
文献类型：
--
作者：
Schwer B;Garg A;Sanchez AM;Bernstein MA;Benjamin B;Shuman S
肌醇焦磷酸 (IPP) 动力学通过对 lncRNA 介导的转录干扰的影响来控制裂殖酵母磷酸稳态调节子的表达。裂殖酵母突变使 IPP 焦磷酸酶失活，从而引发生长缺陷（从患病到致死），这是通过过多的 1,5-IP8 对 RNA 3' 加工和转录终止的激动作用而产生的。为了阐明 IPP 中毒的决定因素，我们对抑制 Asp1 焦磷酸酶突变体疾病的自发突变进行了遗传筛选。我们在裂解和聚腺苷酸化因子复合物的重要 Cft1 亚基中发现了一个错义突变 C823R，该突变甚至抑制致命的 Asp1 IPP 焦磷酸酶突变，从而强化了 3'-加工/终止作为 IPP 毒性目标的情况。抑制子筛选还鉴定了 Gde1 和 Spx1 (SPAC6B12.07c)，两者都具有 IPP 结合 SPX 结构域，并且都是 Asp1 突变引起致死性所必需的。对蛋白质组中其他 SPX 蛋白的调查发现，液泡多磷酸聚合酶的 Vtc4 和 Vtc2 亚基是 IPP 中毒的其他因子。 Gde1、Spx1 和 Vtc4 包含与其 IPP 感应 SPX 结构域融合的酶模块（分别是甘油磷酸二酯酶、环指泛素连接酶和聚磷酸聚合酶）。 IPP 结合位点以及 Gde1 和 Spx1 催化结构域的结构引导诱变表明，这两个模块对于引发 IPP 毒性是必需的。虽然 IPP 毒性需要 Vtc4 聚合酶催化活性，但其 IPP 结合位点则不需要。上位性分析、转录组分析和 Pho1 表达分析表明 Spx1 作为 IP8 信号传导至 3'-加工/转录终止机制的转导子。
Inositol pyrophosphate (IPP) dynamics govern expression of the fission yeast phosphate homeostasis regulon via their effects on lncRNA-mediated transcription interference. The growth defects (ranging from sickness to lethality) elicited by fission yeast mutations that inactivate IPP pyrophosphatase enzymes are exerted via the agonistic effects of too much 1,5-IP8 on RNA 3′-processing and transcription termination. To illuminate determinants of IPP toxicosis, we conducted a genetic screen for spontaneous mutations that suppressed the sickness of Asp1 pyrophosphatase mutants. We identified a missense mutation, C823R, in the essential Cft1 subunit of the cleavage and polyadenylation factor complex that suppresses even lethal Asp1 IPP pyrophosphatase mutations, thereby fortifying the case for 3′-processing/termination as the target of IPP toxicity. The suppressor screen also identified Gde1 and Spx1 (SPAC6B12.07c), both of which have an IPP-binding SPX domain and both of which are required for lethality elicited by Asp1 mutations. A survey of other SPX proteins in the proteome identified the Vtc4 and Vtc2 subunits of the vacuolar polyphosphate polymerase as additional agents of IPP toxicosis. Gde1, Spx1, and Vtc4 contain enzymatic modules (glycerophosphodiesterase, RING finger ubiquitin ligase, and polyphosphate polymerase, respectively) fused to their IPP-sensing SPX domains. Structure-guided mutagenesis of the IPP-binding sites and the catalytic domains of Gde1 and Spx1 indicated that both modules are necessary to elicit IPP toxicity. Whereas Vtc4 polymerase catalytic activity is required for IPP toxicity, its IPP-binding site is not. Epistasis analysis, transcriptome profiling, and assays of Pho1 expression implicate Spx1 as a transducer of IP8 signaling to the 3′-processing/transcription termination machinery.
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DOI：
10.1093/bioinformatics/btu638
发表时间：
2015-01-15
期刊：
Bioinformatics (Oxford, England)
影响因子：
--
作者：
Anders S;Pyl PT;Huber W
通讯作者：
Huber W
影响因子：
48
作者：
Langmead, Ben;Salzberg, Steven L.
通讯作者：
Salzberg, Steven L.
真核mRNA 3'-End加工机械的建筑。
DOI：
10.1126/science.aao6535
发表时间：
2017-11-24
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Casañal A;Kumar A;Hill CH;Easter AD;Emsley P;Degliesposti G;Gordiyenko Y;Santhanam B;Wolf J;Wiederhold K;Dornan GL;Skehel M;Robinson CV;Passmore LA
通讯作者：
Passmore LA
影响因子：
14.8
作者：
Kelley LA;Mezulis S;Yates CM;Wass MN;Sternberg MJ
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Sternberg MJ
影响因子：
1.2
作者：
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