Ent3p and Ent5p exhibit cargo-specific functions in trafficking proteins between the trans-golgi network and the endosomes in yeast
Ent3p and Ent5p exhibit cargo-specific functions in trafficking proteins between the trans-golgi network and the endosomes in yeast
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DOI：
10.1091/mbc.e06-11-1000
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发表时间：
2007-05-01
影响因子：
3.3
通讯作者：
Schekman, Randy
中科院分区：
文献类型：
--
作者：
Copic, Alenka;Starr, Trevor L.;Schekman, Randy
磷酸肌醇结合蛋白Ent 3 p和Ent 5 p是酿酒酵母（Saccharomycescerevisiae）中蛋白质从高尔基体网络（trans-Golgi network，TGN）转运到液泡所必需的。这两种蛋白质都与单体网格蛋白接头Gga 2 p相互作用，但Ent 5 p也与网格蛋白接头蛋白1（AP-1）复合物相互作用，这有助于蛋白质如Chs 3 p在TGN的保留。当ENT 3和ENT 5都发生突变时，Chs 3 p从细胞内储库转移到细胞表面。然而，Ent 3 p和Ent 5 p不是AP-1功能所必需的，而是它们似乎与AP-1平行作用以将蛋白质如Chs 3 p保留在TGN。它们具有网格蛋白衔接子的所有特性，因为它们既可以与网格蛋白结合，也可以与货物蛋白结合。与AP-1一样，Ent 5 p与Chs 3 p结合，而Ent 3 p促进Gga 2 p与内体突触融合蛋白Pep 12 p之间的相互作用。因此，Ent 3 p在Gga依赖性转运至晚期内体中具有额外的功能。Ent 3 p也促进Gga 2 p和网格蛋白之间的关联;然而，Ent 5 p可以部分替代该功能。我们得出结论，网格蛋白衔接子AP-1，Ent 3 p，Ent 5 p和Ggas以不同的方式合作，以分选TGN和内体之间的蛋白质。
The phosphoinositide-binding proteins Ent3p and Ent5p are required for protein transport from the trans-Golgi network (TGN) to the vacuole in Saccharomyces cerevisiae. Both proteins interact with the monomeric clathrin adaptor Gga2p, but Ent5p also interacts with the clathrin adaptor protein 1 (AP-1) complex, which facilitates retention of proteins such as Chs3p at the TGN. When both ENT3 and ENT5 are mutated, Chs3p is diverted from an intracellular reservoir to the cell surface. However, Ent3p and Ent5p are not required for the function of AP-1, but rather they seem to act in parallel with AP-1 to retain proteins such as Chs3p at the TGN. They have all the properties of clathrin adaptors, because they can both bind to clathrin and to cargo proteins. Like AP-1, Ent5p binds to Chs3p, whereas Ent3p facilitates the interaction between Gga2p and the endosomal syntaxin Pep12p. Thus, Ent3p has an additional function in Gga-dependent transport to the late endosome. Ent3p also facilitates the association between Gga2p and clathrin; however, Ent5p can partially substitute for this function. We conclude that the clathrin adaptors AP-1, Ent3p, Ent5p, and the Ggas cooperate in different ways to sort proteins between the TGN and the endosomes.