摘 要：摘 要：胰岛素样生长因子-2受体(insulin-like growth factor-2 receptor, IGF-2r)和非阳离子依赖型甘露糖-6-磷酸受体(cation-independent mannose-6-phosphate receptor, CI-MPR)为同一分子，属多结构域跨膜糖蛋白。IGF-2r与阳离子依赖型M6P受体(cation-dependent mannose-6-phosphotase receptor, CD-MPR)共同介导溶酶体酶的分选和转运过程，对溶酶体的形成起重要作用。IGF-2/M6P受体除能与溶酶体酶、TGF-b前体等M6P配体结合外，还能与非糖基化的IGF-2、视黄酸等作用，调节蛋白质的转运和跨膜信号传导等活动。IGF-2r为父源性印迹(paternal imprinted)基因，基因的印迹、表达受基因印迹控制区(imprinting control region, ICR)的甲基化差异修饰所调控。IGF-2r基因表达缺失出现胎儿肥大、心脏和胎盘发育不全、围产期死亡等异常现象，证明IGF-2r在胚胎发育过程中起重要作用。
关键词：IGF-2r；M6P受体；IGF；溶酶体酶；基因印迹；胚胎发育
Abstract: Abstract: The insulin-like growth factor-II receptor is a multifunctional single transmembrane glycoprotein with multi-domain, which is identical to the cation-independent mannose-6-phosphate (M6P) receptor. The IGF-II/M6P receptor, along with the cation-dependent M6P (CD-M6P) receptor, mediates the intercellular sorting and trafficking of M6P-containing lysosomal enzymes from the trans-Golgi network (TGN) to lysosomes. In addition to lysosomal enzymes, the IGF-II/M6P receptor also binds a diverse spectrum of other M6P containing proteins, including transforming growth factor-b (TGF-b) precursor, as well as non-M6P-containing retinoic acid and IGF-2, thereby regulates a myriad of biological processes, such as protein trafficking and transmembrane signal transduction, to affect the developmental growth and metablism. IGF-2r gene is generally imprinted on the paternally inherited allele and expressed from maternal allele depending on the imprinting control region (ICR) differentially methylated. The IGF-II/M6P receptor plays a critical role in the embryonic development and is supported by the phenotypes that the disruption of the gene resulted in disproportional overgrowth, particularly of the heart and placenta during post-implantation, and perinatal lethality.
Key words: IGF-2 receptor; M6P receptor; IGF; lysosomal enzymes; gene imprinting; embryonic development
