Loss of the novel Vcp (valosin containing protein) interactor Washc4 interferes with autophagy-mediated proteostasis in striated muscle and leads to myopathy in vivo

Autophagy. 2018;14(11):1911-1927. doi: 10.1080/15548627.2018.1491491. Epub 2018 Aug 16.

Abstract

VCP/p97 (valosin containing protein) is a key regulator of cellular proteostasis. It orchestrates protein turnover and quality control in vivo, processes fundamental for proper cell function. In humans, mutations in VCP lead to severe myo- and neuro-degenerative disorders such as inclusion body myopathy with Paget disease of the bone and frontotemporal dementia (IBMPFD), amyotrophic lateral sclerosis (ALS) or and hereditary spastic paraplegia (HSP). We analyzed here the in vivo role of Vcp and its novel interactor Washc4/Swip (WASH complex subunit 4) in the vertebrate model zebrafish (Danio rerio). We found that targeted inactivation of either Vcp or Washc4, led to progressive impairment of cardiac and skeletal muscle function, structure and cytoarchitecture without interfering with the differentiation of both organ systems. Notably, loss of Vcp resulted in compromised protein degradation via the proteasome and the macroautophagy/autophagy machinery, whereas Washc4 deficiency did not affect the function of the ubiquitin-proteasome system (UPS) but caused ER stress and interfered with autophagy function in vivo. In summary, our findings provide novel insights into the in vivo functions of Vcp and its novel interactor Washc4 and their particular and distinct roles during proteostasis in striated muscle cells.

Keywords: Proteostasis; Vcp; Washc4; striated muscle; zebrafish.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Genetically Modified
  • Autophagy / genetics*
  • Embryo, Nonmammalian
  • Gene Deletion
  • HEK293 Cells
  • Humans
  • Intracellular Signaling Peptides and Proteins / genetics
  • Intracellular Signaling Peptides and Proteins / metabolism*
  • Male
  • Mice
  • Muscle, Skeletal / metabolism
  • Muscle, Skeletal / pathology
  • Muscle, Striated / metabolism*
  • Muscle, Striated / pathology
  • Muscular Diseases / genetics*
  • Muscular Diseases / metabolism*
  • Muscular Diseases / pathology
  • Protein Binding
  • Proteostasis / genetics*
  • Valosin Containing Protein / metabolism*
  • Zebrafish / embryology
  • Zebrafish / genetics
  • Zebrafish / metabolism
  • Zebrafish Proteins / genetics
  • Zebrafish Proteins / metabolism*

Substances

  • Intracellular Signaling Peptides and Proteins
  • Zebrafish Proteins
  • washc4 protein, zebrafish
  • Valosin Containing Protein

Grant support

This work was supported by the Deutsche Forschungsgemeinschaft (DFG) [RO2173/4-1 (WR), RO2173/4-2 (WR), JU2859/1–2 (SJ)]; Ministerium Wissenschaft, Forschung und Kunst Baden-Württemberg (MWK) [Juniorprofessurenprogramm 2013]; German Federal Ministry of Education and Research (BMBF) [e:Med-SYMBOL-HF grant #01ZX1407A];