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Spatial and Temporal Analysis of Active ERK in the C. elegans Germline
08:40

Spatial and Temporal Analysis of Active ERK in the C. elegans Germline

Published on: November 29, 2016

Stimulus-specific activation and actin dependency of distinct, spatially separated ERK1/2 fractions in A7r5 smooth

Susanne Vetterkind1, Robert J Saphirstein, Kathleen G Morgan

  • 1Department of Health Sciences, Boston University, Boston, Massachusetts, United States of America. svetter@bu.edu

Plos One
|February 25, 2012
PubMed

Insights

Smooth muscle cell responses to extracellular signal regulated kinases 1 and 2 (ERK1/2) depend on stimulus. Caveolin-1 mediates DPBA-induced ERK1/2 activation, while actin cytoskeleton association regulates FCS-induced proliferation.

Area of Science:

  • Cellular Biology
  • Molecular Biology
  • Cardiovascular Research

Background:

  • Extracellular signal regulated kinases 1 and 2 (ERK1/2) activation in smooth muscle cells is linked to cardiovascular disease.
  • ERK1/2 signaling can promote smooth muscle cell proliferation or regulate contraction in differentiated cells.

Purpose of the Study:

  • To identify factors determining ERK1/2 activation outcomes in smooth muscle cells.
  • To differentiate the roles of caveolin-1 and actin cytoskeleton in ERK1/2 signaling pathways.

Main Methods:

  • Utilized A7r5 smooth muscle cells stimulated with 12-deoxyphorbol 13-isobutylate 20-acetate (DPBA) for cytoskeletal remodeling and fetal calf serum (FCS) for proliferation.
  • Employed knock down experiments, immunoprecipitation, proximity ligation assays, and Triton X fractionation.
  • Investigated the effect of cytochalasin treatment on ERK1/2 phosphorylation.

Main Results:

  • Caveolin-1 mediates ERK1/2 activation by DPBA but not FCS; ERK1/2 is released from caveolin-1 upon DPBA stimulation.
  • ERK1/2 association with the actin cytoskeleton decreases after FCS stimulation but not DPBA stimulation.
  • Actin cytoskeleton is required for DPBA-induced ERK1/2 phosphorylation, as shown by cytochalasin treatment.

Conclusions:

  • Distinct ERK1/2 fractions are regulated independently by specific stimuli in smooth muscle cells.
  • The association of ERK1/2 with the actin cytoskeleton is a critical determinant of ERK1/2 signaling outcomes, influencing proliferation versus other responses.

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