Cvitanich C, Pallisgaard N, Nielsen K A, Hansen A C, Larsen K, Pihakaski-Maunsbach K, Marcker K A, Jensen E O
Laboratory of Gene Expression, Department of Molecular and Structural Biology, University of Aarhus, Gustav Wieds Vej 10, DK-8000 Aarhus C., Denmark.
Proc Natl Acad Sci U S A. 2000 Jul 5;97(14):8163-8. doi: 10.1073/pnas.090468497.
Nodulin genes are specifically expressed in the nitrogen-fixing root nodules. We have identified a novel type of DNA-binding protein (CPP1) interacting with the promoter of the soybean leghemoglobin gene Gmlbc3. The DNA-binding domain of CPP1 contains two similar Cys-rich domains with 9 and 10 Cys, respectively. Genes encoding similar domains have been identified in Arabidopsis thaliana, Caenorhabditis elegans, the mouse, and human. The domains also have some homology to a Cys-rich region present in some polycomb proteins. The cpp1 gene is induced late in nodule development and the expression is confined to the distal part of the central infected tissue of the nodule. A constitutively expressed cpp1 gene reduces the expression of a Gmlbc3 promoter-gusA reporter construct in Vicia hirsuta roots. These data therefore suggest that CPP1 might be involved in the regulation of the leghemoglobin genes in the symbiotic root nodule.
结瘤素基因在固氮根瘤中特异性表达。我们鉴定出一种新型的DNA结合蛋白（CPP1），它与大豆豆血红蛋白基因Gmlbc3的启动子相互作用。CPP1的DNA结合结构域包含两个相似的富含半胱氨酸的结构域，分别含有9个和10个半胱氨酸。在拟南芥、秀丽隐杆线虫、小鼠和人类中已鉴定出编码相似结构域的基因。这些结构域也与一些多梳蛋白中存在的富含半胱氨酸区域有一定同源性。cpp1基因在根瘤发育后期被诱导，其表达局限于根瘤中央受感染组织的远端部分。一个组成型表达的cpp1基因降低了野豌豆根中Gmlbc3启动子 - gusA报告构建体的表达。因此，这些数据表明CPP1可能参与共生根瘤中豆血红蛋白基因的调控。
