Pestov Nikolay A, Kulakovskaya Tatyana V, Kulaev Igor S
Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino 142290, Moscow Region, Russia.
FEMS Yeast Res. 2004 Mar;4(6):643-8. doi: 10.1016/j.femsyr.2003.12.008.
Isolated mitochondria of Saccharomyces cerevisiae cells grown on glucose possess acid-soluble inorganic polyphosphate (polyP). Its level strongly depends on phosphate (P(i)) concentration in the culture medium. The polyP level in mitochondria showed 11-fold decrease under 0.8 mM P(i) as compared with 19.3 mM P(i). When spheroplasts isolated from P(i)-starved cells were incubated in the P(i)-complete medium, they accumulated polyP and exhibited a phosphate overplus effect. Under phosphate overplus the polyP level in mitochondria was two times higher than in the complete medium without preliminary P(i) starvation. The average chain length of polyP in mitochondria was of <15 phosphate residues at 19.3 mM P(i) in the culture medium and increased at phosphate overplus. Deoxyglucose inhibited polyP accumulation in spheroplasts, but had no effect on polyP accumulation in mitochondria. Uncouplers (FCCP, dinitrophenol) and ionophores (monensin, nigericin) inhibited polyP accumulation in mitochondria more efficiently than in spheroplasts. Fast hydrolysis of polyP was observed after sonication of isolated mitochondria. Probably, the accumulation of polyP in mitochondria depended on the proton-motive force of their membranes.
在葡萄糖上生长的酿酒酵母细胞的分离线粒体含有酸溶性无机多聚磷酸盐（多聚P）。其水平强烈依赖于培养基中的磷酸盐（P(i)）浓度。与19.3 mM P(i)相比，在0.8 mM P(i)下线粒体中的多聚P水平下降了11倍。当从P(i)饥饿细胞中分离的原生质体在P(i)完全培养基中孵育时，它们积累多聚P并表现出磷酸盐过量效应。在磷酸盐过量的情况下，线粒体中的多聚P水平比没有预先P(i)饥饿的完全培养基中的高出两倍。在培养基中19.3 mM P(i)时，线粒体中多聚P的平均链长小于15个磷酸残基，并且在磷酸盐过量时增加。脱氧葡萄糖抑制原生质体中的多聚P积累，但对线粒体中的多聚P积累没有影响。解偶联剂（FCCP、二硝基苯酚）和离子载体（莫能菌素、尼日利亚菌素）对线粒体中多聚P积累的抑制作用比对原生质体更有效。分离的线粒体超声处理后观察到多聚P的快速水解。可能，线粒体中多聚P的积累取决于其膜的质子动力。
