Eraso P, Cid A, Serrano R
European Molecular Biology Laboratory, Heidelberg, FRG.
FEBS Lett. 1987 Nov 16;224(1):193-7. doi: 10.1016/0014-5793(87)80446-5.
The activity of the plasma membrane ATPase in growing yeast is increased by low pH and by glucose, conditions which result in a higher demand for proton pumping. The amount of enzyme is not significatively modified under these conditions. The amount of ATPase is only slightly increased by introducing extra copies of its gene in autonomous plasmids. In addition, the expression of the ATPase gene in a multi-copy plasmid causes a reduction of the copy number of the plasmid and slows growth. Therefore, overexpression of the ATPase is detrimental for the cell, justifying a regulatory mechanism based on increasing the catalytic activity and not the amount of enzyme.
生长中的酵母中质膜ATP酶的活性会因低pH值和葡萄糖而增加，这两种条件会导致对质子泵的需求增加。在这些条件下，酶的量没有明显改变。通过在自主质粒中引入其基因的额外拷贝，ATP酶的量仅略有增加。此外，ATP酶基因在多拷贝质粒中的表达会导致质粒拷贝数减少并减缓生长。因此，ATP酶的过表达对细胞有害，这证明了基于增加催化活性而非酶量的调节机制是合理的。
