Zagon I S, Verderame M F, Zimmer W E, McLaughlin P J
Department of Neuroscience and Anatomy, The Pennsylvania State University, College of Medicine, 500 University Drive, Hershey, PA 17033, USA.
Brain Res Mol Brain Res. 2000 Dec 8;84(1-2):106-14. doi: 10.1016/s0169-328x(00)00232-1.
The native opioid growth factor (OGF), [Met(5)]-enkephalin, is a tonic inhibitory peptide that modulates cell proliferation and tissue organization during development, cancer, cellular renewal, wound healing, and angiogenesis. OGF action is mediated by a receptor mechanism. The receptor for OGF, OGFr, has been cloned and sequenced in humans and rats. Using primers based on the rat OGFr cDNA, and a mouse embryo expressed sequence tag, the full-length 2.1 kb mouse OGFr cDNA was sequenced. The open reading frame was found to encode a protein of 634 amino acids, and 14 imperfect repeats of 9 amino acids each were a prominent feature. The molecular weight of OGFr was calculated as 70679, and the isoelectric point was 4.5. Northern blot analysis revealed a 2.1 kb OGFr mRNA transcript in adult mouse brain, heart, lung, liver, kidney, and triceps surae muscle. The amino acids for mouse and rat OGFr were 93% similar and 91% identical, but the mouse and human shared only a 70% similarity and a 58% identity. These results emphasize the molecular validity of OGFr, and explain the interaction of OGF with respect to normal and abnormal growth in mouse cells and tissues.
天然阿片样生长因子（OGF），即[Met(5)]-脑啡肽，是一种具有滋补抑制作用的肽，在发育、癌症、细胞更新、伤口愈合和血管生成过程中调节细胞增殖和组织构建。OGF的作用由一种受体机制介导。OGF的受体OGFr已在人和大鼠中被克隆和测序。利用基于大鼠OGFr cDNA的引物以及一个小鼠胚胎表达序列标签，对全长2.1 kb的小鼠OGFr cDNA进行了测序。发现开放阅读框编码一个由634个氨基酸组成的蛋白质，且有14个由9个氨基酸组成的不完全重复序列，这是一个显著特征。计算得出OGFr的分子量为70679，等电点为4.5。Northern印迹分析显示在成年小鼠的脑、心脏、肺、肝脏、肾脏和腓肠肌中有一个2.1 kb的OGFr mRNA转录本。小鼠和大鼠OGFr的氨基酸相似性为93%，同一性为91%，但小鼠和人类的相似性仅为70%，同一性为58%。这些结果强调了OGFr的分子有效性，并解释了OGF在小鼠细胞和组织正常及异常生长方面的相互作用。
