Ezrin is a downstream effector of trafficking PKC-integrin complexes involved in the control of cell motility

TY - JOUR

T1 - Ezrin is a downstream effector of trafficking PKC-integrin complexes involved in the control of cell motility

AU - Ng, T

AU - Parsons, M

AU - Hughes, W E

AU - Monypenny, J

AU - Zicha, D

AU - Gautreau, A

AU - Arpin, M

AU - Gschmeissner, S

AU - Verveer, P J

AU - Bastiaens, P I H

AU - Parker, P J

PY - 2001/6/1

Y1 - 2001/6/1

N2 - Protein kinase C (PKC) a has been implicated in beta1 integrin-mediated cell migration. Stable expression of PKC alpha is shown here to enhance wound closure. This PKC-driven migratory response directly correlates with increased C-terminal threonine phosphorylation of ezrin/moesin/radixin (ERM) at the wound edge. Both the wound migratory response and ERM phosphorylation are dependent upon the catalytic function of PKC and are susceptible to inhibition by phosphatidylinositol 3-kinase blockade. Upon phorbol 12,13-dibutyrate stimulation, green fluorescent protein-PKC alpha and beta1 integrins co-sediment with ERM proteins in low-density sucrose gradient fractions that are enriched in transferrin receptors, Using fluorescence lifetime imaging microscopy, PKC alpha is shown to form a molecular complex with ezrin, and the PKC-co-precipitated endogenous ERR I is hyperphosphorylated at the C-terminal threonine residue, i.e, activated. Electron microscopy showed an enrichment of both proteins in plasma membrane protrusions. Finally, overexpression of the C-terminal threonine phosphorylation site mutant of ezrin has a dominant inhibitory effect on PKC alpha -induced cell migration. We provide the first evidence that PKC alpha or a PKC alpha -associated serine/threonine kinase can phosphorylate the ERM C-terminal threonine residue within a kinase-ezrin molecular complex in vivo.

AB - Protein kinase C (PKC) a has been implicated in beta1 integrin-mediated cell migration. Stable expression of PKC alpha is shown here to enhance wound closure. This PKC-driven migratory response directly correlates with increased C-terminal threonine phosphorylation of ezrin/moesin/radixin (ERM) at the wound edge. Both the wound migratory response and ERM phosphorylation are dependent upon the catalytic function of PKC and are susceptible to inhibition by phosphatidylinositol 3-kinase blockade. Upon phorbol 12,13-dibutyrate stimulation, green fluorescent protein-PKC alpha and beta1 integrins co-sediment with ERM proteins in low-density sucrose gradient fractions that are enriched in transferrin receptors, Using fluorescence lifetime imaging microscopy, PKC alpha is shown to form a molecular complex with ezrin, and the PKC-co-precipitated endogenous ERR I is hyperphosphorylated at the C-terminal threonine residue, i.e, activated. Electron microscopy showed an enrichment of both proteins in plasma membrane protrusions. Finally, overexpression of the C-terminal threonine phosphorylation site mutant of ezrin has a dominant inhibitory effect on PKC alpha -induced cell migration. We provide the first evidence that PKC alpha or a PKC alpha -associated serine/threonine kinase can phosphorylate the ERM C-terminal threonine residue within a kinase-ezrin molecular complex in vivo.

UR - http://www.scopus.com/inward/record.url?scp=17944372904&partnerID=8YFLogxK

U2 - 10.1093/emboj/20.11.2723

DO - 10.1093/emboj/20.11.2723

M3 - Article

VL - 20

SP - 2723

EP - 2741

JO - EMBO Journal

JF - EMBO Journal

IS - 11

ER -