Vinexin regulates autophagy through YAP/TAZ: implications for health and disease
type: CreativeWork
description: Macroautophagy (hereafter referred to as autophagy) is a highly conserved cellular process that promotes cytoplasmic homeostasis via lysosomal degradation of proteins and organelles. Dysfunctional autophagy occurs in numerous human pathologies, including neurodegeneration and cancer. Vinexin (encoded by SORBS3) is a physiologically important adaptor protein for two main reasons: 1. SORSB3 mRNA expression increases in normal human brain ageing, 2. SORBS3 is a candidate tumour suppressor in hepatocellular carcinoma (HCC). This dissertation builds on published data from an siRNA screen for autophagy regulations under basal conditions, which indicates vinexin knockdown upregulates autophagy. I replicate this finding in multiple cell lines, before characterising the impact of siSORBS3 treatment on autophagy; autophagosome biogenesis is increased, while flux through the autophagy pathway remains intact. Having excluded several possible mechanisms suggested by the literature, I focus on the transcriptional coactivators YAP and TAZ. The rationale here is: 1. YAP/TAZ activity is implicated in autophagy, 2. YAP/TAZ and vinexin are both linked to HCC. My data show that YAP/TAZ transcriptional activity is upregulated upon vinexin depletion. Moreover, increased autophagy following siSORBS3 treatment requires YAP and TAZ. A key focus of this dissertation is the mechanism by which vinexin knockdown upregulates YAP/TAZ and hence, autophagy. This centres on altered actin cytoskeleton dynamics; an increase in F-actin structures appears to compete with YAP/TAZ for binding to angiomotins, established sequesterers of YAP/TAZ in the cytosol. In this way, siSORBS3 treatment facilitates YAP/TAZ nuclear localisation and consequent transcriptional activity. Angiomotin overexpression therefore ameliorates the increase in autophagy caused by vinexin depletion. Published RNA sequencing data is used to confirm that SORBS3 mRNA expression increases in normal brain ageing, not only in the frontal …
abstract: Macroautophagy (hereafter referred to as autophagy) is a highly conserved cellular process that promotes cytoplasmic homeostasis via lysosomal degradation of proteins and organelles. Dysfunctional autophagy occurs in numerous human pathologies, including neurodegeneration and cancer. Vinexin (encoded by SORBS3) is a physiologically important adaptor protein for two main reasons: 1. SORSB3 mRNA expression increases in normal human brain ageing, 2. SORBS3 is a candidate tumour suppressor in hepatocellular carcinoma (HCC). This dissertation builds on published data from an siRNA screen for autophagy regulations under basal conditions, which indicates vinexin knockdown upregulates autophagy. I replicate this finding in multiple cell lines, before characterising the impact of siSORBS3 treatment on autophagy; autophagosome biogenesis is increased, while flux through the autophagy pathway remains intact. Having excluded several possible mechanisms suggested by the literature, I focus on the transcriptional coactivators YAP and TAZ. The rationale here is: 1. YAP/TAZ activity is implicated in autophagy, 2. YAP/TAZ and vinexin are both linked to HCC. My data show that YAP/TAZ transcriptional activity is upregulated upon vinexin depletion. Moreover, increased autophagy following siSORBS3 treatment requires YAP and TAZ. A key focus of this dissertation is the mechanism by which vinexin knockdown upregulates YAP/TAZ and hence, autophagy. This centres on altered actin cytoskeleton dynamics; an increase in F-actin structures appears to compete with YAP/TAZ for binding to angiomotins, established sequesterers of YAP/TAZ in the cytosol. In this way, siSORBS3 treatment facilitates YAP/TAZ nuclear localisation and consequent transcriptional activity. Angiomotin overexpression therefore ameliorates the increase in autophagy caused by vinexin depletion. Published RNA sequencing data is used to confirm that SORBS3 mRNA expression increases in normal brain ageing, not only in the frontal …
author: Frake, Rebecca Astrid
language: en
keywords: Autophagy, YAP/TAZ, Brain ageing, Hepatocellular carcinoma
license: https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/ed4f807e-6664-4cea-b588-af8e8edecaed/download
license: https://www.rioxx.net/licenses/all-rights-reserved/
date published: 2018-04-28
date modified: 2026-07-22T22:24:30Z
provider: Cambridge University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Cambridge

PropertyValue
property ID: DOI
value: 10.17863/CAM.20392