Hamada T, Hasunuma K, Komatsu S
Department of Molecular Biology, National Institute of Agrobiological Resources, Tsukuba, Japan.
Biol Pharm Bull. 1999 Feb;22(2):122-6. doi: 10.1248/bpb.22.122.
The molecular mechanism of light signal perception was analyzed using stem sections of etiolated rice (Oryza sativa L.) seedlings irradiated with red light from a fluorescent lamp. The membrane and cytosol fractions were labeled by 40 nM [gamma-32P]ATP for 10 s at 0 degrees C and proteins were separated by two-dimensional polyacrylamide gel electrophoresis. Phosphorylation of three proteins with molecular weights of 16, 17 and 18 kDa in the rice increased with the intensity of red light irradiation (50 micromol/m2/s) for 16 min. Most of the phosphorylation activity was present in the cytosol fraction. The three proteins cross-reacted with the anti-nucleoside diphosphate (NDP) kinase antibody. Phosphorylation of these proteins was correlated with changes in the activity of NDP kinase. These proteins phosphorylated histone III-S, a substrate for measuring the protein kinase activity. By phospho-amino acid analysis, phosphoserine was found present in the phosphorylated proteins. These rapidly phosphorylated proteins would thus appear to have the features of NDP kinase.
利用来自荧光灯的红光照射黄化水稻（Oryza sativa L.）幼苗的茎段，分析光信号感知的分子机制。在0℃下，用40 nM [γ-32P]ATP对膜和胞质溶胶组分进行10 s标记，然后通过二维聚丙烯酰胺凝胶电泳分离蛋白质。水稻中分子量为16、17和18 kDa的三种蛋白质的磷酸化随着红光照射强度（50 μmol/m2/s）持续16分钟而增加。大部分磷酸化活性存在于胞质溶胶组分中。这三种蛋白质与抗核苷二磷酸（NDP）激酶抗体发生交叉反应。这些蛋白质的磷酸化与NDP激酶活性的变化相关。这些蛋白质使组蛋白III-S磷酸化，组蛋白III-S是用于测量蛋白激酶活性的底物。通过磷酸氨基酸分析，发现磷酸化蛋白质中存在磷酸丝氨酸。因此，这些快速磷酸化的蛋白质似乎具有NDP激酶的特征。
