Filaments and phenotypes: cellular roles and orphan effects associated with mutations in cytoplasmic intermediate filament proteins

F1000Res. 2019 Sep 30;8:F1000 Faculty Rev-1703. doi: 10.12688/f1000research.19950.1. eCollection 2019.

Abstract

Cytoplasmic intermediate filaments (IFs) surround the nucleus and are often anchored at membrane sites to form effectively transcellular networks. Mutations in IF proteins (IFps) have revealed mechanical roles in epidermis, muscle, liver, and neurons. At the same time, there have been phenotypic surprises, illustrated by the ability to generate viable and fertile mice null for a number of IFp-encoding genes, including vimentin. Yet in humans, the vimentin ( VIM) gene displays a high probability of intolerance to loss-of-function mutations, indicating an essential role. A number of subtle and not so subtle IF-associated phenotypes have been identified, often linked to mechanical or metabolic stresses, some of which have been found to be ameliorated by the over-expression of molecular chaperones, suggesting that such phenotypes arise from what might be termed "orphan" effects as opposed to the absence of the IF network per se, an idea originally suggested by Toivola et al. and Pekny and Lane.

Keywords: background effects; chaperones; intermediate filament proteins; mutation; phenotypes; stress response.

Publication types

  • Review

MeSH terms

  • Animals
  • Humans
  • Intermediate Filament Proteins / genetics*
  • Intermediate Filaments / genetics*
  • Mice
  • Mutation
  • Phenotype

Substances

  • Intermediate Filament Proteins

Grant support

The author(s) declared that no grants were involved in supporting this work.