Okorokov L A, Kuranova E V, Silva R dos S
Departamento de Bioquímica Médica, Universidade Federal do Rio de Janeiro, Brazil.
FEMS Microbiol Lett. 1997 Jan 1;146(1):39-46. doi: 10.1111/j.1574-6968.1997.tb10168.x.
Several lines of evidence are presented to show that the Ca(2+)-ATPase activity of total yeast membranes is due to the reticulum (R) type of Ca(2+)-ATPase: (1) Neither calmodulin nor low concentrations of calmodulin antagonists change Ca2+ uptake; (2) removal of plasma membranes (PM) following Con A treatment of spheroplasts (SP) does not significantly alter Ca2+ uptake by the remaining membranes, but increases its specific activity 3.5-fold; (3) after incubation of membranes with [gamma-32P]ATP, SDS-PAGE shows the formation of acyl phosphate intermediates with molecular masses of around 100, 180-190 and 205 kDa; formation of these acyl phosphates requires Ca2+ and is blocked by cyclopiazonic acid, La3+ ions and in the absence of Ca2+. The data on fractionation of yeast membranes are consistent with the suggestion that both the ER and the Golgi are equipped with Ca(2+)-ATPase(s).
有几条证据表明，酵母总膜的Ca(2+)-ATP酶活性归因于内质网（R）型Ca(2+)-ATP酶：（1）钙调蛋白和低浓度的钙调蛋白拮抗剂均不改变Ca2+摄取；（2）用刀豆球蛋白A处理原生质球（SP）后去除质膜（PM），不会显著改变剩余膜的Ca2+摄取，但会使其比活性增加3.5倍；（3）膜与[γ-32P]ATP孵育后，SDS-PAGE显示形成分子量约为·100、180-190和205 kDa的酰基磷酸中间体；这些酰基磷酸的形成需要Ca2+，并被环匹阿尼酸、La3+离子阻断，且在无Ca2+的情况下也会被阻断。酵母膜分级分离的数据与内质网和高尔基体均配备有Ca(2+)-ATP酶的观点一致。
