Cargo selection by the COPII budding machinery during export from the ER.
Cargo selection by the COPII budding machinery during export from the ER.
复制标题
DOI：
10.1083/jcb.141.1.61
复制
发表时间：
1998-04-06
影响因子：
7.8
通讯作者：
Balch, WE
中科院分区：
文献类型：
--
作者：
Aridor, M;Weissman, J;Bannykh, S;Nuoffer, C;Balch, WE
货物选择性地以COPII囊泡的形式从ER出口。为了分析COPII在内质网选择性转运中的作用，我们从大鼠肝细胞浆中纯化了哺乳动物COPII复合体的成分，然后分析了它们在货物选择和内质网输出中的作用。纯化的哺乳动物Sec23-24复合体由85kD(Sec23)蛋白和120kD(SEC24)蛋白组成。虽然Sec23-24复合体或单体Sec23亚基被发现是Sar1激活后被招募到细胞膜上的最小胞浆成分，但哺乳动物Sec13-31复合体的加入是完成发芽所必需的。为了确定货物和外套成分之间可能的蛋白质相互作用，我们将谷胱甘肽-S-转移酶标记的Sar1或GST-Sec23招募到内质网微粒体中。随后，我们使用谷胱甘肽-琼脂糖珠溶解和重新分离标记的亚基，以探测与货物的相互作用。我们发现，激活的Sar1与Sec23或Sec23-24复合体结合是必要的，并且足以高效地将1型跨膜货运蛋白水泡性口炎病毒糖蛋白恢复到洗涤剂可溶的预芽蛋白复合体中，该复合体排除了内质网驻留蛋白。用哺乳动物Sec13-31复合体补充这些最低限度的货物招募条件，可以将选定的货物输出到COPII囊泡中。Cargo与部分COPII外壳相互作用的能力表明，这些蛋白质在萌发前在ER膜上启动货物分选，并确立了依赖GTPase的外壳招募在货物选择中的作用。
Cargo is selectively exported from the ER in COPII vesicles. To analyze the role of COPII in selective transport from the ER, we have purified components of the mammalian COPII complex from rat liver cytosol and then analyzed their role in cargo selection and ER export. The purified mammalian Sec23–24 complex is composed of an 85-kD (Sec23) protein and a 120-kD (Sec24) protein. Although the Sec23–24 complex or the monomeric Sec23 subunit were found to be the minimal cytosolic components recruited to membranes after the activation of Sar1, the addition of the mammalian Sec13–31 complex is required to complete budding. To define possible protein interactions between cargo and coat components, we recruited either glutathione-S-transferase (GST)–tagged Sar1 or GST– Sec23 to ER microsomes. Subsequently, we solubilized and reisolated the tagged subunits using glutathione-Sepharose beads to probe for interactions with cargo. We find that activated Sar1 in combination with either Sec23 or the Sec23–24 complex is necessary and sufficient to recover with high efficiency the type 1 transmembrane cargo protein vesicular stomatitis virus glycoprotein in a detergent-soluble prebudding protein complex that excludes ER resident proteins. Supplementing these minimal cargo recruitment conditions with the mammalian Sec13–31 complex leads to export of the selected cargo into COPII vesicles. The ability of cargo to interact with a partial COPII coat demonstrates that these proteins initiate cargo sorting on the ER membrane before budding and establishes the role of GTPase-dependent coat recruitment in cargo selection.
登录
查看更多内容
影响因子：
64.5
作者：
BALCH, WE;MCCAFFERY, JM;FARQUHAR, MG
通讯作者：
FARQUHAR, MG
影响因子：
7.8
作者：
ESPENSHADE, P;GIMENO, RE;KAISER, CA
通讯作者：
KAISER, CA
影响因子：
64.8
作者：
Kuehn, MJ;Herrmann, JM;Schekman, R
通讯作者：
Schekman, R
Rab1和Ca2+是将载体内质网融合到高尔基体转运的载体囊泡所必需的。
影响因子：
7.8
作者：
Pind, S N;Nuoffer, C;McCaffery, J M;Plutner, H;Davidson, H W;Farquhar, M G;Balch, W E
通讯作者：
Balch, W E
Zeta-cop是涂层囊泡组件所必需的。
影响因子：
7.8
作者：
Kuge, O;Hara-Kuge, S;Orci, L;Ravazzola, M;Amherdt, M;Tanigawa, G;Wieland, F T;Rothman, J E
通讯作者：
Rothman, J E