Centre INRS-Institut Armand-Frappier, Institut National de la Recherche Scientifique, Laval, Québec, Canada H7V 1B7.
Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada H3A 0C7.
Small GTPases. 2020 May;11(3):167-173. doi: 10.1080/21541248.2017.1387686. Epub 2018 Jan 2.
The small GTPase Rab7 is the main regulator of membrane trafficking at late endosomes. This small GTPase regulates endosome-to-trans Golgi Network trafficking of sorting receptors, membrane fusion of late endosomes to lysosomes, and autophagosomes to lysosomes during autophagy. Rab7, like all Rab GTPases, binds downstream effectors coordinating several divergent pathways. How cells regulate these interactions and downstream functions is not well understood. Recent evidence suggests that Rab7 function can be modulated by the combination of several post-translational modifications that facilitate interactions with one effector while preventing binding to another one. In this review, we discuss recent data on how phosphorylation, palmitoylation and ubiquitination modulate the ability of this small GTPase to orchestrate membrane trafficking at the late endosomes.
小GTP酶Rab7是晚期内体膜运输的主要调节因子。这种小GTP酶在自噬过程中调节分拣受体从内体到反式高尔基体网络的运输、晚期内体与溶酶体的膜融合以及自噬体与溶酶体的膜融合。Rab7与所有Rab GTP酶一样，结合下游效应器以协调多种不同的途径。细胞如何调节这些相互作用和下游功能尚不清楚。最近的证据表明，Rab7的功能可以通过几种翻译后修饰的组合来调节，这些修饰促进与一种效应器的相互作用，同时防止与另一种效应器结合。在这篇综述中，我们讨论了关于磷酸化、棕榈酰化和泛素化如何调节这种小GTP酶在晚期内体中协调膜运输能力的最新数据。
