Intracellular and transcellular transport of secretory component and albumin in rat hepatocytes.
Intracellular and transcellular transport of secretory component and albumin in rat hepatocytes.
复制标题
大鼠肝细胞中分泌成分和白蛋白的细胞内和跨细胞转运。
DOI：
10.1083/jcb.97.5.1582
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发表时间：
1983
期刊：
影响因子：
--
通讯作者：
Palade,GE
中科院分区：
文献类型：
--
作者：
Sztul,ES;Howell,KE;Palade,GE
以[~ 3 H]岩藻糖和[~（35）S]半胱氨酸为代谢前体，在大鼠体内研究了肝分泌蛋白和膜蛋白的细胞内和跨细胞转运。测量血浆、胆汁和肝亚细胞组分中的掺入放射性，并通过SDS PAGE分离高尔基复合体、胆汁和血浆的标记蛋白，并通过荧光法进行鉴定。高尔基体组分中的3 H-放射性在注射后10 min达到峰值（p.i.）然后随着血浆中标记糖蛋白的出现而下降。高尔基体分泌岩藻蛋白的最大分泌发生在感染后10至20分钟之间。相反，标记蛋白从高尔基体膜亚组分的清除发生在注射后30分钟，表明膜蛋白离开高尔基复合体至少比大部分内容物蛋白晚30分钟。通过抗IgA抗体与（伊加）2共沉淀，在胆汁中鉴定出主要的80，000-道尔顿形式的分泌组分（SC）。一种针对胆汁中80，000-道尔顿肽的抗体（在兔子体内产生）识别高尔基体膜中两种较大的形式（116，000和94，000道尔顿），推测为前体。35 S-SC和35 S-白蛋白转运动力学的比较研究表明，白蛋白在胆汁中的峰值出现在注射后约45 min，而SC峰出现在感染后80分钟，表明传递到胆小管的血浆和膜蛋白的通过时间不同。
The intra- and transcellular transports of hepatic secretory and membrane proteins were studied in rats in vivo using [3H]fucose and [35S]cysteine as metabolic precursors. Incorporated radioactivity in plasma, bile, and liver subcellular fractions was measured and the labeled proteins of the Golgi complex, bile, and plasma were separated by SDS PAGE and identified by fluorography. 3H-radioactivity in Golgi fractions peaked at 10 min postinjection (p.i.) and then declined concomitantly with the appearance of labeled glycoproteins in plasma. Maximal secretion of secretory fucoproteins from Golgi occurred between 10 and 20 min p.i. In contrast, the clearance of labeled proteins from Golgi membrane subfractions occurred past 30 min p.i., indicating that membrane proteins leave the Golgi complex at least 30 min later than the bulk of content proteins. A major 80,000-dalton form of secretory component (SC) was identified in the bile by co-precipitation with (IgA)2 by an anti-IgA antibody. An antibody (raised in rabbit) against the biliary 80,000-dalton peptide recognized two larger forms (116,000 and 94,000 dalton), presumably precursors, in Golgi membranes. A comparative study of kinetics of transport of 35S-SC and 35S-albumin showed that albumin peaked in bile at approximately 45 min p.i., whereas the SC peak occurred at 80 min p.i., suggesting that the transit time differs for plasma and membrane proteins that are delivered to the bile canaliculus.