Nonmuscle myosin IIA and IIB differentially contribute to intrinsic and directed migration of human embryonic lung fibroblasts

Biochem Biophys Res Commun. 2018 Mar 25;498(1):25-31. doi: 10.1016/j.bbrc.2018.02.171. Epub 2018 Feb 24.


Nonmuscle myosin II (NMII) plays an essential role in directional cell migration. In this study, we investigated the roles of NMII isoforms (NMIIA and NMIIB) in the migration of human embryonic lung fibroblasts, which exhibit directionally persistent migration in an intrinsic manner. NMIIA-knockdown (KD) cells migrated unsteadily, but their direction of migration was approximately maintained. By contrast, NMIIB-KD cells occasionally reversed their direction of migration. Lamellipodium-like protrusions formed in the posterior region of NMIIB-KD cells prior to reversal of the migration direction. Moreover, NMIIB KD led to elongation of the posterior region in migrating cells, probably due to the lack of load-bearing stress fibers in this area. These results suggest that NMIIA plays a role in steering migration by maintaining stable protrusions in the anterior region, whereas NMIIB plays a role in maintenance of front-rear polarity by preventing aberrant protrusion formation in the posterior region. These distinct functions of NMIIA and NMIIB might promote intrinsic and directed migration of normal human fibroblasts.

Keywords: Cell migration; Cytoskeleton; Migratory cell polarity; Nonmuscle myosin II.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line
  • Cell Movement*
  • Cell Polarity
  • Cell Shape
  • Embryo, Mammalian / cytology*
  • Fibroblasts / cytology*
  • Gene Knockdown Techniques
  • Humans
  • Nonmuscle Myosin Type IIA / metabolism*
  • Nonmuscle Myosin Type IIB / metabolism*
  • Phosphorylation
  • Pseudopodia / metabolism
  • Stress Fibers / metabolism


  • Nonmuscle Myosin Type IIA
  • Nonmuscle Myosin Type IIB