The calcium-sensing receptor changes cell shape via a beta-arrestin-1 ARNO ARF6 ELMO protein network

J Cell Sci. 2007 Aug 1;120(Pt 15):2489-97. doi: 10.1242/jcs.03469. Epub 2007 Jul 10.

Abstract

G-protein-coupled receptors (GPCRs) transduce the binding of extracellular stimuli into intracellular signalling cascades that can lead to morphological changes. Here, we demonstrate that stimulation of the calcium-sensing receptor (CaSR), a GPCR that promotes chemotaxis by detecting increases in extracellular calcium, triggers plasma membrane (PM) ruffling via a pathway that involves beta-arrestin 1, Arf nucleotide binding site opener (ARNO), ADP-ribosylating factor 6 (ARF6) and engulfment and cell motility protein (ELMO). Expression of dominant negative beta-arrestin 1 or its knockdown with siRNA impaired the CaSR-induced PM ruffling response. Expression of a catalytically inactive ARNO also reduced CaSR-induced PM ruffling. Furthermore, beta-arrestin 1 co-immunoprecipitated with the CaSR and ARNO under resting conditions. Agonist treatment did not markedly alter beta-arrestin 1 binding to the CaSR or to ARNO but it did elicit the translocation and colocalisation of the CaSR, beta-arrestin 1 and ARNO to membrane protrusions. Furthermore, ARF6 and ELMO, two proteins known to couple ARNO to the cytoskeleton, were required for CaSR-dependent morphological changes and translocated to the PM ruffles. These data suggest that cells ruffle upon CaSR stimulation via a mechanism that involves translocation of beta-arrestin 1 pre-assembled with the CaSR or ARNO, and that ELMO plays an essential role in this CaSR-signalling-induced cytoskeletal reorganisation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ADP-Ribosylation Factor 6
  • ADP-Ribosylation Factors / isolation & purification
  • ADP-Ribosylation Factors / metabolism*
  • Actins / isolation & purification
  • Actins / metabolism
  • Adaptor Proteins, Signal Transducing / isolation & purification
  • Adaptor Proteins, Signal Transducing / metabolism*
  • Arrestins / isolation & purification
  • Arrestins / metabolism*
  • Calcium / metabolism*
  • Cell Line
  • Cell Membrane / metabolism
  • Cell Movement / physiology
  • Cell Shape*
  • GTPase-Activating Proteins / isolation & purification
  • GTPase-Activating Proteins / metabolism*
  • Humans
  • Receptors, Calcium-Sensing / isolation & purification
  • Receptors, Calcium-Sensing / metabolism*
  • beta-Arrestin 1
  • beta-Arrestins

Substances

  • ADP-Ribosylation Factor 6
  • ARRB1 protein, human
  • Actins
  • Adaptor Proteins, Signal Transducing
  • Arrestins
  • ELMO1 protein, human
  • GTPase-Activating Proteins
  • Receptors, Calcium-Sensing
  • beta-Arrestin 1
  • beta-Arrestins
  • cytohesin-2
  • ADP-Ribosylation Factors
  • ARF6 protein, human
  • Calcium