小GTP酶Rab9长期以来被描述为介导内体到反式高尔基网络(TGN)运输的蛋白质,特别是甘露糖-6-磷酸受体(MPR)再循环。然而,研究表明Rab9也与内溶酶体区室的分选途径有关,从而对这一观点提出了挑战。我们最近对Rab9的时空动力学进行了表征,通过使用活细胞成像,我们发现它在早期之间的过渡阶段与CI-MPR一起进入内体途径,Rab5阳性,迟到了,Rab7a阳性,内体。更多,Rab9组成型活性突变体,Rab9Q66L,在晚期内体上积累并促进TGN的载体形成。这里,我们根据以前关于Rab9在逆行转运途径中的报道讨论我们的发现。
The small GTPase Rab9 has long been described as a protein that mediates endosome-to-trans-Golgi Network (TGN) transport, and specifically mannose-6-phospate receptor (MPR) recycling. However, studies have challenged this view by showing that Rab9 also is connected to sorting pathways toward the endolysosomal compartments. We recently characterized the spatio-temporal dynamics of Rab9 and, by using live cell imaging, we showed that it enters the endosomal pathway together with CI-MPR at the transition stage between early, Rab5-positive, and late, Rab7a-positive, endosomes. More so, the Rab9 constitutively active mutant, Rab9Q66L, accumulates on late endosomes and promotes carrier formation at the TGN. Here, we discuss our findings in light of previous reports on Rab9 in the retrograde transport pathway.