Instituto de Investigaciones Biomédicas Alberto Sols, Department of Experimental Models of Human Diseases, Consejo Superior de Investigaciones Científicas (CSIC)/Universidad Autónoma Madrid (UAM), 28029-Madrid, Spain.
Instituto de Investigaciones Biomédicas Alberto Sols, Department of Experimental Models of Human Diseases, Consejo Superior de Investigaciones Científicas (CSIC)/Universidad Autónoma Madrid (UAM), 28029-Madrid, Spain
Dis Model Mech. 2019 Feb 22;12(2):dmm036681. doi: 10.1242/dmm.036681.
Members of the VPS13 family are associated with various human diseases. In particular, the loss of function of VPS13A leads to chorea-acanthocytosis (ChAc), a rare neurodegenerative disease without available curative treatments. Autophagy has been considered a promising therapeutic target because the absence of VPS13A causes a defective autophagy flux. However, the mechanistic details of this deficiency are unknown. Here, we identified Rab7A as an interactor of one of the VPS13 family members in and showed that this interaction is conserved between the human homologs VPS13A and RAB7A in HeLa cells. As RAB7A is a key player in endosome trafficking, we addressed the possible function of VPS13A in endosome dynamics and lysosome degradation. Our results suggest that the decrease in autophagy observed in the absence of VPS13A may be the result of a more general defect in endocytic trafficking and lysosomal degradation. Unexpectedly, we found that VPS13A is closely localized to mitochondria, suggesting that the role of VPS13A in the endolysosomal pathway might be related to inter-organelle communication. We show that VPS13A localizes at the interface between mitochondria-endosomes and mitochondria-endoplasmic reticulum and that the presence of membrane contact sites is altered in the absence of VPS13A. Based on these findings, we propose that therapeutic strategies aimed at modulating the endolysosomal pathway could be beneficial in the treatment of ChAc.This article has an associated First Person interview with the first author of the paper.
VPS13 家族的成员与各种人类疾病有关。特别是 VPS13A 的功能丧失会导致舞蹈棘红细胞增多症(ChAc),这是一种罕见的神经退行性疾病,目前尚无有效的治疗方法。自噬已被认为是一种很有前途的治疗靶点,因为 VPS13A 的缺失会导致自噬流缺陷。然而,这种缺陷的机制细节尚不清楚。在这里,我们鉴定了 Rab7A 是 中的一个 VPS13 家族成员的相互作用蛋白,并表明在 HeLa 细胞中,这种相互作用在人类同源物 VPS13A 和 RAB7A 之间是保守的。由于 RAB7A 是内体运输的关键参与者,我们研究了 VPS13A 在内涵体动力学和溶酶体降解中的可能功能。我们的结果表明,在缺乏 VPS13A 的情况下观察到的自噬减少可能是内吞作用运输和溶酶体降解更普遍缺陷的结果。出乎意料的是,我们发现 VPS13A 与线粒体密切定位,这表明 VPS13A 在内体溶酶体途径中的作用可能与细胞器间的通讯有关。我们表明 VPS13A 定位于线粒体-内涵体和线粒体-内质网的界面,并且在缺乏 VPS13A 的情况下膜接触位点的存在发生改变。基于这些发现,我们提出靶向调节内体溶酶体途径的治疗策略可能有益于 ChAc 的治疗。本文有该论文第一作者的相关第一人称采访。