Serine phosphorylation of the secreted extracellular domain of APP.
Serine phosphorylation of the secreted extracellular domain of APP.
复制标题
DOI：
10.1006/bbrc.1993.2490
复制
发表时间：
1993-12
影响因子：
3.1
通讯作者：
J. Knops;S. Gandy;P. Greengard;I. Lieberburg;S. Sinha
中科院分区：
文献类型：
--
作者：
J. Knops;S. Gandy;P. Greengard;I. Lieberburg;S. Sinha
在稳定转染的细胞中研究了全长 APP (FL-APP) 和分泌型 APP (s-APP) 的磷酸化状态。在佛波酯不存在和存在的情况下，在成熟的全长 APP 中均检测到 32P 掺入。令人惊讶的是，32P-磷酸盐被掺入分泌的胞外域中，并且这对于用大量过量的 PNGase F 处理 [32P]-磷酸-s-APP 是稳定的，表明 N-连接寡糖位点不能解释磷酸盐掺入。 [32P]-磷酸-s-APP 的磷酸氨基酸分析结果恢复了[32P]-磷酸丝氨酸作为优势物种。 Brefeldin A 完全抑制 [32P]-磷酸 s-APP 的释放，但不抑制 32P 掺入 FL-APP，表明磷酸化发生在中央液泡途径的早期。一种新的管腔或细胞外蛋白激酶的胞外域磷酸化可能在调节 APP 的代谢命运中发挥作用。
The phosphorylation status of full-length APP (FL-APP) and secreted APP (s-APP) was investigated in stably transfected cells. 32P incorporation was detected in the mature full-length APP both in the absence and presence of phorbol ester. Surprisingly, 32P-phosphate was incorporated in the secreted ectodomain, and this was stable to treatment of the [32P]-phospho-s-APP with a large excess of PNGase F, suggesting that N-linked oligosaccharide sites do not account for phosphate incorporation. Phosphoamino acid analysis of the [32P]-phospho-s-APP resulted in the recovery of [32P]-phosphoserine as the preponderant species. Brefeldin A completely inhibited the release of [32P]-phospho s-APP, but did not inhibit the incorporation of 32P into the FL-APP, suggesting that phosphorylation occurs early in the central vacuolar pathway. It is possible that ectodomain phosphorylation by a novel luminal or extracellular protein kinase may play a role in regulating the metabolic fate of APP.