Hasunuma Kohji, Yabe Naoto, Yoshida Yusuke, Ogura Yasunobu, Hamada Tohru
Kihara Institute for Biological Research, Graduate School of Integrated Science, Yokohama City University Maioka-cho, Totsuka-ku, Yokohama, Japan.
J Bioenerg Biomembr. 2003 Feb;35(1):57-65. doi: 10.1023/a:1023493823368.
The putative functions of NDP (nucleoside diaphosphate) kinases from various organisms focusing to fungi and plants are described. The biochemical reactions catalyzed by NDP kinase are as follows. (i) Phosphotransferring activity from mainly ATP to cognate NDPs generating nucleoside triphosphates (NTPs). (ii) Autophosphorylation activity from ATP and GTP. (iii) Protein kinase (phosphotransferring) activity phosphorylating such as myelin basic protein. NDP kinase could function to provide NTPs as a housekeeping enzyme. However, recent works proved possible functions of the NDP kinases in the processes of signal transduction in various organisms, as described below. 1) By use of the extracts of the mycelia of a filamentous fungus Neurospora crassa blue-light irradiation could increase the phosphorylation of a 15-kDa protein, which was purified and identified to be NDP kinase (NDK-1). By use of the etiolated seedlings of Pisum sativum cv Alaska and Oryza sativa red-light irradiation of intact plants increased the phosphorylation of NDP kinase. However, successive irradiation by red-far-red reversed the reaction, indicating that phytochrome-mediated light signals are transduced to the phosphorylation of NDP kinase. 2) NDP kinase localizing in mitochondria is encoded by nuclear genome and different from those localized in cytoplasm. NDP kinase in mitochondria formed a complex with succinyl CoA synthetase. 3) In Spinicia oleraceae two different NDP kinases were detected in the chloroplast, and in Pisum sativum two forms of NDP kinase originated from single species of mRNA could be detected in the choloroplast. However, the function of NDP kinases in the choloroplast is not yet known. 4) In Neurospora crassa a Pro72His mutation in NDP kinase (ndk-1Pro72His) deficient in the autophosphorylation and protein kinase activity resulted in lacking the light-induced polarity of perithecia. In wild-type directional light irradiation parallel to the solid medium resulted in the formation of the perithecial beak at the top of perithecia, which was designated as "light-induced polarity of perithecia." In wild-type in darkness the beak was formed at random places on perithecia, and in ndkPro72His mutant the perithecial beak was formed at random places even under directional light illumination. The introduction of genomic DNA and cDNA for ndk-1 demonstrated that the wild-type DNAs suppressed the mutant phenotype. With all these results except for the demonstration in Neurospora, most of the phenomena are elusive and should be solved in the molecular levels concerning with NDP kinases.
本文描述了来自各种生物体（重点是真菌和植物）的核苷二磷酸（NDP）激酶的假定功能。NDP激酶催化的生化反应如下：（i）主要从ATP向同源NDP进行磷酸转移活性，生成核苷三磷酸（NTP）；（ii）来自ATP和GTP的自磷酸化活性；（iii）使髓鞘碱性蛋白等发生磷酸化的蛋白激酶（磷酸转移）活性。NDP激酶可能作为一种管家酶发挥作用以提供NTP。然而，如下所述，最近的研究证明了NDP激酶在各种生物体信号转导过程中可能具有的功能。1）利用丝状真菌粗糙脉孢菌的菌丝体提取物，蓝光照射可增加一种15 kDa蛋白的磷酸化，该蛋白经纯化后鉴定为NDP激酶（NDK - 1）。利用豌豆品种阿拉斯加和水稻的黄化幼苗，完整植株的红光照射可增加NDP激酶的磷酸化。然而，连续的红光 - 远红光照射可使该反应逆转，这表明光敏色素介导的光信号被转导至NDP激酶的磷酸化过程。2）定位于线粒体的NDP激酶由核基因组编码，与定位于细胞质的NDP激酶不同。线粒体中的NDP激酶与琥珀酰辅酶A合成酶形成复合物。3）在菠菜叶绿体中检测到两种不同的NDP激酶，在豌豆叶绿体中可检测到源自单一mRNA的两种形式的NDP激酶。然而，叶绿体中NDP激酶的功能尚不清楚。4）在粗糙脉孢菌中，NDP激酶（ndk - 1Pro72His）中Pro72His突变导致自磷酸化和蛋白激酶活性缺陷，从而使子囊壳缺乏光诱导极性。在野生型中，平行于固体培养基的定向光照射会导致子囊壳顶部形成子囊喙，这被称为“子囊壳的光诱导极性”。在野生型黑暗条件下，喙在子囊壳的随机位置形成，而在ndkPro72His突变体中，即使在定向光照下，子囊喙也在随机位置形成。导入ndk - 1的基因组DNA和cDNA表明野生型DNA可抑制突变体表型。除了在粗糙脉孢菌中的证明外，所有这些结果中的大多数现象都难以捉摸，应在与NDP激酶相关的分子水平上加以解决。
