Hardie D G, MacKintosh R W
Biochemistry Department, University, Dundee, Scotland, UK.
Bioessays. 1992 Oct;14(10):699-704. doi: 10.1002/bies.950141011.
Mammalian AMP-activated protein kinase is the central component of a protein kinase cascade which inactivates three key enzymes involved in the synthesis or release of free fatty acids and cholesterol inside the cell. The kinase cascade is activated by elevation of AMP, and perhaps also by fatty acid and cholesterol metabolites. The system may fulfil a protective function, preventing damage caused by depletion of ATP or excessive intracellular release of free lipids, a type of stress response. Recent evidence suggests that it may have been in existence for at least a billion years, since a very similar protein kinase cascade is present in higher plants. This system therefore represents an early eukaryotic protein kinase cascade, which is unique in that it is regulated by intracellular metabolites rather than extracellular signals or cell cycle events.
哺乳动物的AMP激活蛋白激酶是蛋白激酶级联反应的核心组成部分，该级联反应会使参与细胞内游离脂肪酸和胆固醇合成或释放的三种关键酶失活。激酶级联反应通过AMP水平升高激活，也可能由脂肪酸和胆固醇代谢产物激活。该系统可能具有保护功能，防止因ATP耗竭或细胞内游离脂质过度释放导致的损伤，这是一种应激反应。最近的证据表明，它可能已经存在了至少十亿年，因为高等植物中存在非常相似的蛋白激酶级联反应。因此，该系统代表了一种早期的真核蛋白激酶级联反应，其独特之处在于它受细胞内代谢产物调节，而非细胞外信号或细胞周期事件。
