Biosynthesis, glycosylation, movement through the Golgi system, and transport to lysosomes by an N-linked carbohydrate-independent mechanism of three lysosomal integral membrane proteins.
Biosynthesis, glycosylation, movement through the Golgi system, and transport to lysosomes by an N-linked carbohydrate-independent mechanism of three lysosomal integral membrane proteins.
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生物合成、糖基化、通过高尔基体系统的运动，以及通过三种溶酶体整合膜蛋白的 N 连接碳水化合物独立机制转运到溶酶体。
DOI：
10.1016/s0021-9258(18)66630-x
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发表时间：
1986
期刊：
影响因子：
--
通讯作者：
Sandoval
中科院分区：
文献类型：
--
作者：
J. G. Barriocanal;Juan;Bonifacino;Lydia Yuan;Ignacio;Sandoval
使用特异性抗 LIMP 单克隆抗体，在正常大鼠肾细胞中研究了三种溶酶体整合膜蛋白 (LIMPS) 的生物合成、糖基化、通过高尔基体系统的运动、转运到溶酶体以及周转。免疫电子显微镜研究揭示了次级溶酶体、高尔基池以及位于跨高尔基池区域的包被和未包被囊泡中存在 LIMP。脉冲追踪实验记录了 27 (LIMP I)、72 (LIMP II) 和 86 kDa (LIMP III) 的 LIMP 前体以及 35-50 (LIMP I)、74 (LIMP II) 和 90-100 kDa (LIMP III) 的成熟 LIMP。关于 LIMP 获得内切糖苷酶 H 抗性的时间过程研究表明，所有三种 LIMP 在合成后 30-60 分钟内从内质网中的合成位点移动到内侧高尔基体。所有三种 LIMP 在离开高尔基体系统之前均已完全糖基化，在此过程中 LIMP I 保留在细胞器的反侧。通过独立于 N 连接碳水化合物的机制合成后，LIMP I 到达溶酶体的半衰期为 2 小时，LIMP II 和 III 到达溶酶体的半衰期为 1 小时。不含 N 连接碳水化合物的 LIMP 的半衰期比完全糖基化的 LIMP 短得多，这表明糖在保护 LIMP 免遭蛋白水解降解方面发挥着重要作用。双免疫荧光显微镜实验表明，LIMP I、LIMP II 和 LIMP III 位于相同的溶酶体中。
The biosynthesis, glycosylation, movement through the Golgi system, transport to lysosomes, and turnover of three lysosomal integral membrane proteins (LIMPSs) have been studied in normal rat kidney cells using specific anti-LIMP monoclonal antibodies. Immunoelectron microscopy studies revealed the presence of LIMPs in secondary lysosomes, Golgi cisterna, and coated and uncoated vesicles located in the trans-Golgi cisterna, area. Pulse-chase experiments recorded LIMP precursors of 27 (LIMP I), 72 (LIMP II), and 86 kDa (LIMP III) and mature LIMPs of 35-50 (LIMP I), 74 (LIMP II), and 90-100 kDa (LIMP III). Time course studies on the acquisition of endoglycosidase H resistance by LIMPs indicated that all three LIMPs moved from the site of their synthesis in the endoplasmic reticulum to the medial Golgi within 30-60 min after their synthesis. All three LIMPs were fully glycosylated before leaving the Golgi system, the process during which LIMP I was retained in the trans side of the organelle. LIMP I reached the lysosomes with a halftime of 2 h and LIMPs II and III with half-times of 1 h after their synthesis by a mechanism that was independent of N-linked carbohydrates. LIMPs free of N-linked carbohydrates displayed much shorter half-lives than fully glycosylated LIMPs, suggesting an important role of the sugars in protecting LIMPs against proteolytic degradation. Double immunofluorescence microscopy experiments showed that LIMP I, LIMP II, and LIMP III are localized in the same lysosomes.