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

9603884 Roux检测到位于细胞壁和细胞核中的植物apyrase，其形式上是一种降解ntps/ndp的酶，为研究该酶的功能的提议提供了基础。这种酶是光诱导的。该蛋白在壁隙或细胞核中的定位受钙/钙调蛋白依赖的信号过程调节，并与DNA和钙调蛋白结合。转基因反义apyrase拟南芥表现出发育异常，这种异常可以通过外源的三磷酸腺苷来调节。基于这些发现的假说认为，这种酶在分生组织中扮演着一个角色，它依赖于光线和控制游离钙含量的内部激素变化来调节细胞生长。这项工作从不同的角度探讨了转基因植物的功能特征：免疫细胞学定位，基因敲除实验，以及转基因植物的生化和生理研究。最近有文献记载的一个方面是，这种酶在正在经历凋亡性死亡的细胞中含量丰富，例如在发育中的木质部导管的细胞中。这项工作结合了几种方法来描述一种独特的酶的功能特征，这种酶具有作为发育决定的主要参与者的所有特征，包括细胞凋亡。

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.