[HTML][HTML] Active ERK/MAP kinase is targeted to newly forming cell–matrix adhesions by integrin engagement and v‐Src

VJ Fincham, M James, MC Frame, SJ Winder - The EMBO journal, 2000 - embopress.org
VJ Fincham, M James, MC Frame, SJ Winder
The EMBO journal, 2000embopress.org
Integrin engagement generates cellular signals leading to the recruitment of structural and
signalling molecules which, in concert with rearrangements of the actin cytoskeleton, leads
to the formation of focal adhesion complexes. Using antisera reactive either with total ERK or
with phosphorylated/activated forms of ERK, in rat embryo fibroblasts and embryonic avian
cells that express v‐Src, we found that active ERK is targeted to newly forming focal
adhesions after integrin engagement or activation of v‐Src. UO126, an inhibitor of MAP …
Abstract
Integrin engagement generates cellular signals leading to the recruitment of structural and signalling molecules which, in concert with rearrangements of the actin cytoskeleton, leads to the formation of focal adhesion complexes. Using antisera reactive either with total ERK or with phosphorylated/activated forms of ERK, in rat embryo fibroblasts and embryonic avian cells that express v‐Src, we found that active ERK is targeted to newly forming focal adhesions after integrin engagement or activation of v‐Src. UO126, an inhibitor of MAP kinase kinase 1 (MEK1), suppressed focal adhesion targeting of active ERK and cell spreading. Also, integrin engagement and v‐Src induced myosin light chain kinase (MLCK)‐dependent phosphorylation of myosin light chain downstream of the MEK/ERK pathway, and MLCK and myosin activities are required for the focal adhesion targeting of ERK. The translocation of active ERK to newly forming focal adhesions may direct specificity towards appropriate downstream targets that influence adhesion assembly. These findings support a role for ERK in the regulation of the adhesion/cytoskeletal network and provide an explanation for the role of ERK in cell motility.
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