Mughal S, Al-Bader A A, Cuschieri A, Kharbat B
Department of Anatomy, Faculty of Medicine, University of Kuwait.
Cell Tissue Res. 1987 Nov;250(2):349-54. doi: 10.1007/BF00219079.
HeLa cells in a monolayer culture were synchronized to S, G2 and mitotic phases by use of excess (2.5 mM) deoxythymidine double-block technique. The localizations of Ca2++-activated adenosine triphosphatase (ATPase) at different phases of the cell cycle were studied using light- and electron-microscopic histochemical techniques, and microphotometric comparisons of the densities of reaction products. Enzyme reaction product was always localized in the endoplasmic reticulum, nuclear membrane, mitochondria and Golgi apparatus, but there were qualitative and quantitative differences related to the phases of the cell cycle. In S phase the activity was mainly concentrated in a perinuclear area of the cytoplasm whereas in G2 and mitosis the activity was scattered throughout the cell. The total activity per cell was maximal in G2, was less in S phase and least in mitosis. Activity in the mitochondria and endoplasmic reticulum was distinctly less in mitosis than in other phases of the cell cycle. The mitochondrial ATPase differed from the ATPase at other sites in ion dependence and sensitivity to oligomycin. The results suggest that there may be several distinct ATPases in proliferating cells.
单层培养的HeLa细胞通过使用过量（2.5 mM）脱氧胸苷双阻断技术同步至S期、G2期和有丝分裂期。利用光学和电子显微镜组织化学技术以及反应产物密度的显微光度比较，研究了Ca2++激活的三磷酸腺苷酶（ATP酶）在细胞周期不同阶段的定位。酶反应产物总是定位于内质网、核膜、线粒体和高尔基体，但与细胞周期阶段相关存在定性和定量差异。在S期，活性主要集中在细胞质的核周区域，而在G2期和有丝分裂期，活性分散在整个细胞中。每个细胞的总活性在G2期最高，在S期较低，在有丝分裂期最低。线粒体和内质网中的活性在有丝分裂期明显低于细胞周期的其他阶段。线粒体ATP酶在离子依赖性和对寡霉素的敏感性方面与其他部位的ATP酶不同。结果表明，增殖细胞中可能存在几种不同的ATP酶。
