Glucose-induced calcium influx in budding yeast involves a novel calcium transport system and can activate calcineurin
Glucose-induced calcium influx in budding yeast involves a novel calcium transport system and can activate calcineurin
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DOI：
10.1016/j.ceca.2011.03.006
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发表时间：
2011-06-01
期刊：
影响因子：
4
通讯作者：
Tisi, Renata
中科院分区：
文献类型：
--
作者：
Groppi, Silvia;Belotti, Fiorella;Tisi, Renata
将葡萄糖添加到葡萄糖饥饿的酿酒酵母细胞中会触发细胞外环境中的钙快速而短暂地流入。在酵母中，至少鉴定出两种不同的载体系统：需要 Cch1 通道的高亲和力系统和低亲和力系统。在这里，我们报告酵母中存在另一种尚未鉴定的钙转运系统，当这两种已知系统失活时，它可以替代它们。该系统称为GIC（葡萄糖诱导钙）系统，它是一种高亲和力钙转运系统，对镁敏感但耐镍。此外，GIC转运对钆和硝苯地平敏感，但对维拉帕米的抑制不敏感，而维拉帕米相反充当葡萄糖反应的激动剂。 GIC 转运在钙调神经磷酸酶活性的情况下完全发挥作用，钙调神经磷酸酶是一种丝氨酸/苏氨酸特异性磷酸酶，参与钙稳态调节和许多其他细胞现象，如对高浓度 Na(+) 和 Li(+) 的耐受、对信息素的反应和基因转录调节。在此，首次报道钙调磷酸酶也可以被营养物质激活：在细胞外钙存在的情况下添加葡萄糖后，在去抑制细胞中观察到钙调磷酸酶对 Crz1 转录因子的激活。 (C) 2011 Elsevier Ltd. 保留所有权利。
Glucose addition to glucose-starved Saccharomyces cerevisiae cells triggers a quick and transient influx of calcium from the extracellular environment. In yeast at least two different carrier systems were identified: a high affinity system, requiring Cch1 channel, and a low affinity system. Here we report that another calcium transport system exists in yeast, not yet identified, that can substitute the two known systems when they are inactivated. This system was called GIC (for Glucose Induced Calcium) system and it is a high affinity calcium transport system, magnesium-sensitive but nickel-resistant. Moreover,GIC transport is sensitive to gadolinium and nifedipine, but it is not sensitive to inhibition by verapamil, which conversely behaves as an agonist on glucose response. GIC transport is fully functional in conditions when calcineurin is active, a serine/threonine specificity phosphatase involved in the regulation of calcium homeostasis and in many other cellular phenomena such as tolerance to high concentrations of Na(+) and Li(+), response to pheromones and gene transcription regulation. Here it is reported for the first time that calcineurin can also be activated by nutrients: the activation of Crz1 transcription factor by calcineurin was observed in derepressed cells after addition of glucose in the presence of extracellular calcium. (C) 2011 Elsevier Ltd. All rights reserved.