Evans D E, Theodoulou F L, Williamson I M, Boyce J M
School of Biological and Molecular Sciences, Oxford Brooks University, Headington, UK.
Symp Soc Exp Biol. 1994;48:43-59.
Active calcium transport in higher plant cell membranes involves both H(+)-linked antiport (at the tonoplast) and direct (P-type) calcium pumping ATPases. Both systems act to remove calcium from the cytoplasm either by pumping it into intracellular stores or into the apoplast. This chapter considers recent advances in our knowledge of the calcium-pumping ATPases of the plant cell, located both at the plasma membrane and in intracellular membranes. Progress in characterising the types of Ca2+ pump in plant cells is particularly important as it becomes increasingly clear that designations applicable to other eukaryotic Ca2+ pumps ('PM-type' and 'SR/ER type') are much less relevant for plant cells. Responses of plant Ca2+ pumps to mammalian Ca2+ pump inhibitors and differences in estimated relative molecular mass also underline the differences between plant and animal Ca2+ pumps. Molecular cloning has resulted in the identification of an SR/ER type Ca2+ pump in plants strongly homologous to that of mammals. These advances are put into the context of research aims in characterising the function and mechanisms of the plant Ca2+ pumps, and their role not only in regulating cytosolic free calcium concentrations, but also in providing intracellular signalling pools and in the regulation of secretion is discussed.
高等植物细胞膜中的主动钙转运涉及H⁺偶联反向转运（液泡膜处）和直接（P型）钙泵ATP酶。这两种系统都通过将钙泵入细胞内储存库或质外体来将钙从细胞质中移除。本章探讨了我们对位于质膜和细胞内膜中的植物细胞钙泵ATP酶认识的最新进展。随着越来越清楚地认识到适用于其他真核生物钙泵（“质膜型”和“肌浆网/内质网型”）的命名对植物细胞的相关性要小得多，鉴定植物细胞中钙泵类型的进展尤为重要。植物钙泵对哺乳动物钙泵抑制剂的反应以及估计相对分子质量的差异也突显了植物和动物钙泵之间的差异。分子克隆已导致在植物中鉴定出一种与哺乳动物的肌浆网/内质网型钙泵高度同源的钙泵。这些进展被置于研究目标的背景下，以表征植物钙泵的功能和机制，并且讨论了它们不仅在调节胞质游离钙浓度方面的作用，还在提供细胞内信号池和分泌调节方面的作用。
