Activation of Rac by Asef2 promotes myosin IIdependent contractility to inhibit cell migration on type I collagen

Leólène Jean, Devi Majumdar, Mingjian Shi, Louis E. Hinkle, Nicole L. Diggins, Mingfang Ao, Joshua A. Broussard, J. Corey Evans, David P. Choma, Donna J. Webb*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

17 Scopus citations


Summary Non-muscle myosin II (MyoII) contractility is central to the regulation of numerous cellular processes, including migration. Rho is a well-characterized modulator of actomyosin contractility, but the function of other GTPases, such as Rac, in regulating contractility is currently not well understood. Here, we show that activation of Rac by the guanine nucleotide exchange factor Asef2 (also known as SPATA13) impairs migration on type I collagen through a MyoII-dependent mechanism that enhances contractility. Knockdown of endogenous Rac or treatment of cells with a Rac-specific inhibitor decreases the amount of active MyoII, as determined by serine 19 (S19) phosphorylation, and negates the Asef2-promoted increase in contractility. Moreover, treatment of cells with blebbistatin, which inhibits MyoII activity, abolishes the Asef2-mediated effect on migration. In addition, Asef2 slows the turnover of adhesions in protrusive regions of cells by promoting large mature adhesions, which has been linked to actomyosin contractility, with increased amounts of active β1 integrin. Hence, our data reveal a new role for Rac activation, promoted by Asef2, in modulating actomyosin contractility, which is important for regulating cell migration and adhesion dynamics.

Original languageEnglish (US)
Pages (from-to)5585-5597
Number of pages13
JournalJournal of cell science
Issue number24
StatePublished - Dec 15 2013


  • Actomyosin
  • Adhesion dynamics
  • Asef2
  • Guanine nucleotide exchange factor
  • Rho GTPases
  • SPATA13
  • β1 integrin

ASJC Scopus subject areas

  • Cell Biology


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