Tomita Y, Kim D H, Magoori K, Fujino T, Yamamoto T T
Tohoku University Gene Research Center, Sendai, 981-8555, Japan.
J Biochem. 1998 Oct;124(4):784-9. doi: 10.1093/oxfordjournals.jbchem.a022180.
We report herein the identification of a novel member of the low-density lipoprotein receptor (LDLR) family termed LDLR-related protein 4 (LRP4). Murine LRP4 cDNA encodes a 1113-amino-acid type II membrane-like protein with eight ligand-binding repeats in two clusters. Southern blot analysis of genomic DNA from several different organisms suggests the presence of LRP4 homologues in chicken lacking the gene encoding apolipoprotein E, which is recognized by the ligand-binding repeats of LDLR. LRP4 transcripts were detected almost exclusively in heart in mouse and humans. Despite the presence of the ligand-binding repeats, COS cells transfected with LRP4 did not show surface-binding of beta-migrating very-low-density lipoprotein, suggesting that LRP4 plays a role in a pathway other than lipoprotein metabolism.
我们在此报告鉴定出一种低密度脂蛋白受体（LDLR）家族的新成员，称为低密度脂蛋白受体相关蛋白4（LRP4）。小鼠LRP4 cDNA编码一种1113个氨基酸的II型膜样蛋白，在两个簇中有八个配体结合重复序列。对几种不同生物体的基因组DNA进行的Southern印迹分析表明，在缺乏载脂蛋白E编码基因的鸡中存在LRP4同源物，载脂蛋白E可被LDLR的配体结合重复序列识别。在小鼠和人类中，LRP4转录本几乎只在心脏中检测到。尽管存在配体结合重复序列，但用LRP4转染的COS细胞未显示β迁移极低密度脂蛋白的表面结合，这表明LRP4在脂蛋白代谢以外的途径中发挥作用。
