来自高层植物的高亲和度吸收输送器的结构和运输机制
D P Schachtman1, J I Schroeder
1Department of Biology, University of California, San Diego, La Jolla 92093-0116.
Nature
|August 25, 1994
概括
研究人员确定了一种小麦膜蛋白,HKT1,对于植物中高亲和度 (K+) 吸收至关重要. 这一发现澄清了植物营养和农业生产力的关键途径.
科学领域:
- 植物生物学 植物生物学
- 分子生物学分子生物学
- 农业科学 农业科学
背景情况:
- (K+) 对植物营养,生长和透调节至关重要,其摄入量是农业中的限制因素.
- 虽然低亲和度K+吸收通过道发生,但植物中高亲和度K+吸收机制在很大程度上是未知的.
研究的目的:
- 确定和描述负责植物高亲和度 (K+) 吸收的分子机制.
- 阐明关键蛋白质的结构和功能,参与有效的K+营养物质获取.
主要方法:
- 使用表达式克隆,从小麦根中分离了一个编码膜蛋白的互补DNA (cDNA).
- 对分离的蛋白质 (HKT1) 进行了功能性表征,以评估其基质亲和力,和动力学和离子选择性.
主要成果:
- 一种新型的膜蛋白HKT1被发现,显示出高亲和度的K+吸收能力.
- HKT1表现出经典高亲和度K+吸收的特征,包括基质亲和度,和度和离子选择性.
- 确定HKT1的传输机制是K(+) -H+共吸收,其表达局限于关键的根和叶区域.
结论:
- HKT1是植物高亲和度吸收途径的关键组成部分,对于植物营养至关重要.
- 了解HKT1的功能可以为提高作物产量的策略提供信息,并解决与农业中金属毒性相关的挑战.
相关概念视频
01:47Primary Active Transport
In contrast to passive transport, active transport involves a substance being moved through membranes in a direction against its concentration or electrochemical gradient. There are two types of active transport: primary active transport and secondary active transport. Primary active transport utilizes chemical energy from ATP to drive protein pumps that are embedded in the cell membrane. With energy from ATP, the pumps transport ions against their electrochemical gradients—a direction they...
01:55Secondary Active Transport
One example of how cells use the energy contained in electrochemical gradients is demonstrated by glucose transport into cells. The ion vital to this process is sodium (Na+), which is typically present in higher concentrations extracellularly than in the cytosol. Such a concentration difference is due, in part, to the action of an enzyme “pump” embedded in the cellular membrane that actively expels Na+ from a cell. Importantly, as this pump contributes to the high concentration of...
02:12Short-distance Transport of Resources
Short-distance transport refers to transport that occurs over a distance of just 2-3 cells, crossing the plasma membrane in the process. Small uncharged molecules, such as oxygen, carbon dioxide, and water, can diffuse across the plasma membrane on their own. In contrast, ions and larger molecules require the assistance of transport proteins due to their charge or size. Transport across membranes also occurs within individual cells, playing a variety of essential roles for the plant as a whole.
01:29Primary Active Transport
In contrast to passive transport, active transport involves a substance being moved through membranes in a direction against its concentration or electrochemical gradient. There are two types of active transport: primary active transport and secondary active transport. Primary active transport utilizes chemical energy from ATP to drive protein pumps embedded in the cell membrane. With energy from ATP, the pumps transport ions against their electrochemical gradients—a direction they would not...
01:32Secondary Active Transport
One example of how cells use the energy contained in electrochemical gradients is demonstrated by glucose transport into cells. The ion vital to this process is sodium (Na+), which is typically present in higher concentrations extracellularly than in the cytosol. Such a concentration difference is due, in part, to the action of an enzyme "pump" embedded in the cellular membrane that actively expels Na+ from a cell. Importantly, as this pump contributes to the high concentration of...
01:29Primary Active Transport
In contrast to passive transport, active transport involves a substance being moved through membranes in a direction against its concentration or electrochemical gradient. There are two types of active transport: primary active transport and secondary active transport. Primary active transport utilizes chemical energy from ATP to drive protein pumps embedded in the cell membrane. With energy from ATP, the pumps transport ions against their electrochemical gradients—a direction they would not...