Affordable Access

deepdyve-link
Publisher Website

The actin/MKL1 signalling pathway influences cell growth and gene expression through large-scale chromatin reorganization and histone post-translational modifications.

Authors
  • Flouriot, Gilles
  • Huet, Guillaume
  • Demay, Florence
  • Pakdel, Farzad
  • Boujrad, Noureddine
  • Michel, Denis
Type
Published Article
Journal
Biochemical Journal
Publisher
Portland Press
Publication Date
Jul 15, 2014
Volume
461
Issue
2
Pages
257–268
Identifiers
DOI: 10.1042/BJ20131240
PMID: 24762104
Source
Medline
License
Unknown

Abstract

In addition to soluble factors, mechanical constraints and extracellular matrix stiffness are important regulators of cell fate that are mediated by cytoskeletal modifications. The EMT (epithelial-mesenchymal transition) that occurs during normal development and malignant progression is a typical example of the phenotypic switch associated with profound actin remodelling and changes in gene expression. For instance, actin dynamics control motile cell functions in EMT, in part, through regulating the subcellular localization of the myocardin-related transcription factor MKL1 (megakaryoblastic leukaemia translocation 1), a co-activator of SRF (serum-responsive factor). In the present paper, we show that MKL1 participates also to the control of the cellular switch between growth and quiescence. Experimental disconnection between MKL1 and G-actin (globular actin), by using an MKL1 mutant or enhancing the F (filamentous)-/G-actin ratio, generates a widely open chromatin state and a global increase in biosynthetic activity, classically associated with cell growth. Conversely, G-actin accumulation favours nuclear condensation and cell quiescence. These large-scale chromatin changes rely upon extensive histone modifications, exemplified by that of H3K9 (H3 Lys9) shifting from trimethylation, a heterochromatin mark, to acetylation, a mark of euchromatin. The present study provides the first evidence for a global reversible hetero/euchromatinization phenomenon triggered by the actin/MKL1 signalling pathway.

Report this publication

Statistics

Seen <100 times