Huber B E
Division of Experimental Therapy, Wellcome Research Laboratories, Research Triangle Park, North Carolina 27709.
Mol Pharmacol. 1992 Apr;41(4):639-44.
The major and minor forms of the asialoglycoprotein receptor (ASGP-R), designated in the rat as RHL-1 and RHL-2/3, respectively, have traditionally been considered to be expressed exclusively in hepatic parenchymal cells. Northern blot analysis now demonstrates that rat and mouse testis express a receptor similar to the RHL-1 ASGP-R but not the RHL-2/3 receptor. In situ hybridization studies demonstrate that late-stage mouse and rat spermatids are the testicular cells that express the RHL-1 ASGP-R. The rat spermatid RHL-1 receptor has functional binding capability, with a KD of approximately 1.4 x 10(-8) M, and similar characteristics, compared with the hepatic RHL-1 receptor, regarding ligand binding specificity and ion dependence. These findings have major implications for therapeutic procedures attempting to target cytotoxic agents or DNA to hepatocytes using the ASGP-R. In addition, these findings demonstrate that late-stage spermatids are transcriptionally active and suggest that the RHL-1 receptor may have a functional role in sperm maturation and/or fertilization.
去唾液酸糖蛋白受体（ASGP-R）的主要和次要形式，在大鼠中分别被命名为RHL-1和RHL-2/3，传统上一直被认为仅在肝实质细胞中表达。Northern印迹分析现在表明，大鼠和小鼠睾丸表达一种与RHL-1 ASGP-R相似的受体，但不表达RHL-2/3受体。原位杂交研究表明，晚期小鼠和大鼠精子细胞是睾丸中表达RHL-1 ASGP-R的细胞。大鼠精子细胞RHL-1受体具有功能结合能力，KD约为1.4×10（-8）M，与肝RHL-1受体相比，在配体结合特异性和离子依赖性方面具有相似的特征。这些发现对于试图利用ASGP-R将细胞毒性剂或DNA靶向肝细胞治疗程序具有重要意义。此外，这些发现表明晚期精子细胞具有转录活性，并提示RHL-1受体可能在精子成熟和/或受精中具有功能作用。
