Hexokinase as a sugar sensor in higher plants
Hexokinase as a sugar sensor in higher plants
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DOI：
10.1105/tpc.9.1.5
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发表时间：
1997-01-01
期刊：
影响因子：
11.6
通讯作者：
Sheen, J
中科院分区：
文献类型：
--
作者：
Jang, JC;Leon, P;Sheen, J
高等植物识别和响应糖的机制在很大程度上是未知的。在这里，我们提出的证据表明，在己糖同化途径，己糖激酶（HXK）的第一个酶，作为传感器的植物糖反应。表达反义己糖激酶（AtHXK）基因的转基因拟南芥植物是糖低敏感的，而过表达AtHXK的植物是糖高敏感的。转基因植株在幼苗发育和基因激活及抑制中表现出广泛的糖反应改变。此外，过量表达酵母糖传感器YHXK2引起显性负效应，通过提高HXK催化活性但降低转基因植物的糖敏感性。这一结果表明，HXK是一种双功能酶，具有独特的调节功能，在植物和酵母之间不可互换。
The mechanisms by which higher plants recognize and respond to sugars are largely unknown. Here, we present evidence that the first enzyme in the hexose assimilation pathway, hexokinase (HXK), acts as a sensor for plant sugar responses. Transgenic Arabidopsis plants expressing antisense hexokinase (AtHXK) genes are sugar hyposensitive, whereas plants overexpressing AtHXK are sugar hypersensitive. The transgenic plants exhibited a wide spectrum of altered sugar responses in seedling development and in gene activation and repression. Furthermore, overexpressing the yeast sugar sensor YHXK2 caused a dominant negative effect by elevating HXK catalytic activity but reducing sugar sensitivity in transgenic plants. The result suggests that HXK is a dual-function enzyme with a distinct regulatory function not interchangeable between plants and yeast.