Bourbon H M, Lapeyre B, Amalric F
Centre de Recherche de Biochimie et de Génétique Cellulaires du CNRS, Toulouse, France.
J Mol Biol. 1988 Apr 20;200(4):627-38. doi: 10.1016/0022-2836(88)90476-7.
Nucleolin is a multifunctional nucleolar protein involved in the synthesis, packaging and maturation of pre-rRNA in eukaryotic cells. We describe the molecular organization and complete sequence of the mouse nucleolin gene, the first higher eukaryotic gene encoding a protein that is both an RNA binding protein involved in rRNA processing and a specific nucleolar protein. The nucleolin gene extends over 9000 base-pairs and is split into 14 exons that encode the 706 amino acid residues of the protein. The promoter sequence is G + C-rich (67% G + C) with four G/C boxes, it lacks bona fide TATA and CAAT boxes and shows capping site heterogeneity. The existence of pyrimidine-rich motifs, similar to those found in the promoter of ribosomal protein genes, could be relevant to the co-regulation of genes whose products are involved in ribosome biogenesis. Nucleolin contains four RNA binding domains, each about 80 amino acid residues long, which include the 11-residue core ribonucleoprotein consensus motif. Each domain is encoded by two exons, with an intervening sequence interrupting the conserved core motif at roughly the same amino acid position. This latter result suggests that the RNA binding domains are composed of two independent subdomains, whose functions remain to be determined.
核仁素是一种多功能核仁蛋白，参与真核细胞中前体核糖体RNA（pre-rRNA）的合成、包装和成熟过程。我们描述了小鼠核仁素基因的分子结构和完整序列，它是首个编码一种既是参与rRNA加工的RNA结合蛋白又是特异性核仁蛋白的高等真核基因。核仁素基因跨度超过9000个碱基对，被分割为14个外显子，这些外显子编码该蛋白的706个氨基酸残基。其启动子序列富含G + C（67% G + C），有四个G/C盒，缺乏典型的TATA盒和CAAT盒，并且表现出帽位点异质性。富含嘧啶的基序的存在，类似于在核糖体蛋白基因启动子中发现的那些基序，可能与对其产物参与核糖体生物发生的基因的协同调控有关。核仁素包含四个RNA结合结构域，每个结构域大约有80个氨基酸残基长，其中包括11个残基的核心核糖核蛋白共有基序。每个结构域由两个外显子编码，中间序列在大致相同的氨基酸位置打断保守的核心基序。后一个结果表明，RNA结合结构域由两个独立的亚结构域组成，其功能还有待确定。
