Syntaxin 1A is delivered to the apical and basolateral domains of epithelial cells: the role of munc-18 proteins.
Syntaxin 1A is delivered to the apical and basolateral domains of epithelial cells: the role of munc-18 proteins.
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突触融合蛋白 1A 被递送至上皮细胞的顶端和基底外侧区域：munc-18 蛋白的作用。
DOI：
10.1242/jcs.114.18.3323
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发表时间：
2001
影响因子：
4
通讯作者：
Patrizia Rosa
中科院分区：
文献类型：
--
作者：
J. Rowe;Federico Calegari;Elena Taverna;Renato Longhi;Patrizia Rosa
SNARE（可溶性N-乙基-马来酰亚胺敏感因子附着蛋白受体）蛋白组装成紧密的核心复合物，促进载体囊泡与靶区室的融合。这类蛋白质的成员在所有真核细胞中表达，并分布在不同的亚细胞区室中。SNARE分选到其生理作用位点的分子机制仍然知之甚少。在这里，我们分析了上皮细胞中的突触融合蛋白1A的转运。与以前的数据一致，我们发现突触融合蛋白1A不被转运到质膜，而是在MDCK和Caco-2细胞中过表达时保留在细胞内。munc-18-1共转染后，其向细胞表面的递送恢复。此外，munc-18的普遍存在的同种型munc-18-2的过表达也能够拯救t-SNARE的转运。syntaxin 1A和munc-18之间的相互作用发生在生物合成途径中，并且是促进t-SNARE从高尔基复合体退出所必需的。这使我们能够研究syntaxin 1A在极化细胞中的靶向作用。极化单层的共聚焦分析表明，突触融合蛋白1A被传递到顶端和基底外侧域独立的munc-18蛋白在共转染实验中使用。在搜索突触融合蛋白1A分选到细胞表面的机制时，我们发现一部分蛋白质包含在非离子去污剂不溶性复合物中。我们的研究结果表明，munc-18蛋白质的限制，但在运输syntaxin 1A从高尔基复合体的上皮细胞表面的重要因素。他们还建议存在共显性的顶端和基底外侧分选信号的syntaxin 1A序列。
SNARE (Soluble N-ethyl-maleimide sensitive factor Attachment protein Receptor) proteins assemble in tight core complexes, which promote fusion of carrier vesicles with target compartments. Members of this class of proteins are expressed in all eukaryotic cells and are distributed in distinct subcellular compartments. The molecular mechanisms underlying sorting of SNAREs to their physiological sites of action are still poorly understood. Here have we analyzed the transport of syntaxin1A in epithelial cells. In line with previous data we found that syntaxin1A is not transported to the plasma membrane, but rather is retained intracellularly when overexpressed in MDCK and Caco-2 cells. Its delivery to the cell surface is recovered after munc-18-1 cotransfection. Furthermore, overexpression of the ubiquitous isoform of munc-18, munc-18-2, is also capable of rescuing the transport of the t-SNARE. The interaction between syntaxin 1A and munc-18 occurs in the biosynthetic pathway and is required to promote the exit of the t-SNARE from the Golgi complex. This enabled us to investigate the targeting of syntaxin1A in polarized cells. Confocal analysis of polarized monolayers demonstrates that syntaxin1A is delivered to both the apical and basolateral domains independently of the munc-18 proteins used in the cotranfection experiments. In search of the mechanisms underlying syntaxin 1A sorting to the cell surface, we found that a portion of the protein is included in non-ionic detergent insoluble complexes. Our results indicate that the munc-18 proteins represent limiting but essential factors in the transport of syntaxin1A from the Golgi complex to the epithelial cell surface. They also suggest the presence of codominant apical and basolateral sorting signals in the syntaxin1A sequence.
影响因子：
7.5
作者：
Fanning, AS;Anderson, JM
通讯作者：
Anderson, JM
DOI：
10.1073/pnas.91.6.2003
发表时间：
1994-03-15
影响因子：
11.1
作者：
GARCIA, EP;GATTI, E;DECAMILLI, P
通讯作者：
DECAMILLI, P