Xu Ruqiang, Li Qingshun Quinn
Department of Botany, Miami University, Oxford, OH 45056, USA.
Plant Mol Biol. 2003 Sep;53(1-2):37-50. doi: 10.1023/b:plan.0000009256.01620.a6.
RING zinc-finger proteins play important roles in the regulation of development in a variety of organisms. In the plant kingdom, few genes encoding RING zinc-finger proteins have been documented with visible effects on plant growth and development. A novel gene, RIE1, encoding a RING-H2 zinc-finger protein was identified in Arabidopsis thaliana and is characterized in this paper. RIE1 encodes a predicted protein product of 359 amino acids residues with a molecular mass of 40 kDa, with a RING-H2 zinc-finger motif located at the extreme end of the C-terminus. Characterization of a Dissociation (Ds) insertion line (SGT4559) and a T-DNA insertion line (SRIE1) demonstrated that disruption of RIE1 is embryo-lethal. SGT4559 heterozygous plants produced seeds with embryo development arrested from globular to torpedo stages. Some mutant seeds were rescued by embryo culture, and the mutant (rie1) plants seemed to grow normally compared to wild-type plants, except that the mutants produced only abnormal seeds. However, RIE1 was expressed in different tissues throughout the whole plant as revealed by northern blot analysis and gene fusion assay of RIE1 promoter with the beta-glucuronidase (GUS) gene. Our results indicated that RIE1 plays an essential role in seed development.
环状锌指蛋白在多种生物体的发育调控中发挥着重要作用。在植物界，很少有编码环状锌指蛋白的基因被证明对植物生长发育有明显影响。本文鉴定了拟南芥中一个编码环状H2锌指蛋白的新基因RIE1，并对其进行了表征。RIE1编码一个预测的由359个氨基酸残基组成的蛋白质产物，分子量为40 kDa，其环状H2锌指基序位于C末端的最末端。对一个解离（Ds）插入系（SGT4559）和一个T-DNA插入系（SRIE1）的表征表明，RIE1的破坏是胚胎致死的。SGT4559杂合植株产生的种子，其胚胎发育在球形期到鱼雷期之间停止。一些突变种子通过胚胎培养得以挽救，与野生型植株相比，突变体（rie1）植株似乎生长正常，只是突变体只产生异常种子。然而，通过Northern印迹分析以及RIE1启动子与β-葡萄糖醛酸酶（GUS）基因的基因融合分析表明，RIE1在整株植物的不同组织中均有表达。我们的结果表明，RIE1在种子发育中起重要作用。
