Otero R C, Gaillardin C
Laboratoire de Génétique Moléculaire et Cellulaire INRA-CNRS, Institut National Agronomique Paris-Grignon, Thiverval-Grignon, France.
Mol Gen Genet. 1996 Sep 13;252(3):311-9. doi: 10.1007/BF02173777.
In the yeast Yarrowia lipolytica the levels of the alkaline extracellular protease (AEP) and acid extracellular protease (AXP) are controlled by the pH of the growth medium. When the pH of growth medium is kept close to 4.0, levels of AXP are high and those of AEP are low, whereas at pH above 6.0 the opposite is true. Mutations which mimic the effects on the protease system of growth at alkaline pH have been identified in two genes, RPH1 and RPH2, in Y. lipolytica. Detailed genetic studies showed that mutations in these two genes are dominant in heterozygous diploids, and that their effects are additive in haploid double mutants. These mutants show that pH regulates AEP expression independently from other metabolic signals. These mutants are not detectably affected in their growth rates, nor in internal pH homeostasis.
在解脂耶氏酵母中，碱性胞外蛋白酶（AEP）和酸性胞外蛋白酶（AXP）的水平受生长培养基pH值的控制。当生长培养基的pH值保持在接近4.0时，AXP的水平较高而AEP的水平较低，而在pH值高于6.0时则相反。在解脂耶氏酵母的两个基因RPH1和RPH2中已鉴定出模拟碱性pH条件下生长对蛋白酶系统影响的突变。详细的遗传学研究表明，这两个基因中的突变在杂合二倍体中是显性的，并且它们在单倍体双突变体中的作用是累加的。这些突变体表明pH独立于其他代谢信号调节AEP的表达。这些突变体的生长速率以及内部pH稳态均未受到明显影响。
