Significance of a Novel Light-Regulated Apyrase for Plant Growth and Development

9603884 Roux植物腺苷三磷酸双磷酸酶（形式上是一种水解NTP/NDP的酶）位于细胞壁和细胞核中的检测为研究该酶的功能提供了基础。 这种酶是光诱导的。 蛋白质在壁空间或细胞核中的定位由钙/钙调蛋白依赖性信号传导过程调节，并结合DNA和钙调蛋白。 转反义腺苷三磷酸双磷酸酶基因拟南芥表现出发育异常，这可以通过外部添加ATP来介导。 基于这些发现的假设假定酶在分生组织中的作用，其调节依赖于光和控制游离钙量的内部激素变化的细胞生长。 本文从免疫细胞学定位、基因敲除实验、转基因植物的生理生化研究等不同角度对转基因植物的功能特性进行了探讨。 最近有文献记载的一个方面是，这种酶在经历凋亡性死亡的细胞中是丰富的，例如在发育中的木质部导管中的细胞中。 这项工作结合了几种方法来对一种独特的酶进行功能表征，这种酶具有作为发育决定（包括凋亡细胞死亡）的主要参与者的所有特征。

9603884 Roux The detection of a plant apyrase, formally an enzyme that hydrolyzes NTPs/NDPs, to be located both in the cell wall and in the nucleus provides the basis for a proposal to study the function of the enzyme. The enzyme is light-induced. Localization of the protein in either wall space or nucleus is regulated by a calcium/calmodulin-dependent signaling process and binds DNA and calmodulin. Transgenic antisense-apyrase Arabidopsis show developmental abnormalities which can be mediated by the external addition of ATP. The hypothesis based on such findings assumes a role for the enzyme in meristematic tissues that regulates cell growth dependent on light and internal hormonal changes that control amounts of free calcium. The proposed work approaches the functional characterization from different angles: immunocytological localization, knock-out experiments, and biochemical and physiological studies in transgenic plants. One aspect, documented very recently, is that the enzyme is abundant in cells that are undergoing apoptotic death, for example in cells in developing xylem vessels. The work combines several approaches to a functional characterization of a unique enzyme that has all the characteristics as a major player in developmental decisions, including apoptotic cell death.