Taguchi Tomohiko, Misaki Ryo
Institute for Molecular Bioscience; University of Queensland; Brisbane, Queensland Australia.
Small GTPases. 2011 Mar;2(2):82-84. doi: 10.4161/sgtp.2.2.15245.
We recently showed that palmitoylated Ras proteins (H-Ras and N-Ras) localize intracellularly at recycling endosomes (REs) and that REs act as a way-station for Ras proteins as they move along the post-Golgi exocytic pathway to the plasma membrane (PM). Palmitoylation is essential for H-Ras/N-Ras targeting to REs. H-Ras requires two palmitoyl groups for RE targeting. A lack of either or both palmitoyl groups causes H-Ras to be mislocalized to the endoplasmic reticulum (ER), the Golgi apparatus, or the PM. In this commentary, we summarize recent progress about the Ras trafficking cycle between the endomembranes (endosomes/ER/Golgi) and the PM. We further discuss (1) the critical determinants of RE targeting of lipidated proteins and (2) possible Ras-mediated signaling pathways that originate from REs.
我们最近发现，棕榈酰化的Ras蛋白（H-Ras和N-Ras）在细胞内定位于再循环内体（REs），并且当Ras蛋白沿着高尔基体后分泌途径移动到质膜（PM）时，REs充当它们的中转站。棕榈酰化对于H-Ras/N-Ras靶向REs至关重要。H-Ras靶向REs需要两个棕榈酰基团。缺少任何一个或两个棕榈酰基团都会导致H-Ras错误定位于内质网（ER）、高尔基体或质膜。在这篇评论中，我们总结了关于Ras在内膜（内体/内质网/高尔基体）和质膜之间运输循环的最新进展。我们还进一步讨论了（1）脂化蛋白靶向REs的关键决定因素，以及（2）可能起源于REs的Ras介导的信号通路。
