Department of Biology, National and Kapodistrian University of Athens, Panepistimioupolis, 15784, Greece.
Department of Biology, National and Kapodistrian University of Athens, Panepistimioupolis, 15784, Greece
Genetics. 2018 Aug;209(4):1121-1138. doi: 10.1534/genetics.118.301240. Epub 2018 Jun 20.
The AP-1 complex is essential for membrane protein traffic via its role in the pinching-off and sorting of secretory vesicles (SVs) from the -Golgi and/or endosomes. While its essentiality is undisputed in metazoa, its role in simpler eukaryotes seems less clear. Here, we dissect the role of AP-1 in the filamentous fungus and show that it is absolutely essential for growth due to its role in clathrin-dependent maintenance of polar traffic of specific membrane cargoes toward the apex of growing hyphae. We provide evidence that AP-1 is involved in both anterograde sorting of RabE-labeled SVs and RabA/B-dependent endosome recycling. Additionally, AP-1 is shown to be critical for microtubule and septin organization, further rationalizing its essentiality in cells that face the challenge of cytoskeleton-dependent polarized cargo traffic. This work also opens a novel issue on how nonpolar cargoes, such as transporters, are sorted to the eukaryotic plasma membrane.
AP-1 复合物对于通过其在从 -高尔基体和/或内体出芽和分选分泌小泡 (SV) 中的作用对于膜蛋白运输是必不可少的。虽然它在后生动物中的重要性是毋庸置疑的，但它在更简单的真核生物中的作用似乎不太清楚。在这里，我们剖析了 AP-1 在丝状真菌中的作用，并表明由于其在网格蛋白依赖性维持特定膜货物向生长菌丝顶端的极性运输中的作用，AP-1 对于生长是绝对必需的。我们提供的证据表明，AP-1 参与了 RabE 标记的 SV 的正向分拣以及 RabA/B 依赖性内体再循环。此外，AP-1 对于微管和隔膜的组织也至关重要，这进一步证明了其在面临细胞骨架依赖性极性货物运输挑战的细胞中的重要性。这项工作还提出了一个新问题，即如何将非极性货物（如转运蛋白）分拣到真核质膜上。
