Stabilization of cortical actin induces internalization of transient receptor potential 3 (Trp3)-associated caveolar Ca2+ signaling complex and loss of Ca2+ influx without disruption of Trp3-inositol trisphosphate receptor association

J Biol Chem. 2001 Nov 9;276(45):42401-8. doi: 10.1074/jbc.M106956200. Epub 2001 Aug 27.

Abstract

Ca(2+) influx via plasma membrane Trp3 channels is proposed to be regulated by a reversible interaction with inositol trisphosphate receptor (IP(3)R) in the endoplasmic reticulum. Condensation of the cortical actin layer has been suggested to physically disrupt this interaction and inhibit Trp3-mediated Ca(2+) influx. This study examines the effect of cytoskeletal reorganization on the localization and function of Trp3 and key Ca(2+) signaling proteins. Calyculin-A treatment resulted in formation of condensed actin layer at the plasma membrane; internalization of Trp3, Galpha(q/11), phospholipase Cbeta, and caveolin-1; and attenuation of 1-oleoyl-2-acetyl-sn-glycerol- and ATP-stimulated Sr(2+) influx. Importantly, Trp3 and IP(3)R-3 remained co-localized inside the cell and were co-immunoprecipitated. Jasplakinolide also induced internalization of Trp3 and caveolin-1. Pretreatment of cells with cytochalasin D or staurosporine did not affect Trp3 but prevented calyculin-A-induced effects. Based on these data, we suggest that Trp3 is assembled in a caveolar Ca(2+) signaling complex with IP(3)R, SERCA, Galpha(q/11), phospholipase Cbeta, caveolin-1, and ezrin. Furthermore, our data demonstrate that conditions which stabilize cortical actin induce loss of Trp3 activity due to internalization of the Trp3-signaling complex, not disruption of IP(3)R-Trp3 interaction. This suggests that localization of the Trp3-associated signaling complex, rather than Trp3-IP(3)R coupling, depends on the status of the actin cytoskeleton.

MeSH terms

  • Actins / physiology*
  • Calcium / metabolism*
  • Calcium Channels / analysis
  • Calcium Channels / metabolism*
  • Calcium Signaling*
  • Calcium-Transporting ATPases / analysis
  • Caveolae / chemistry*
  • Caveolin 1
  • Caveolins / analysis
  • Cells, Cultured
  • Cytoskeleton / physiology
  • Humans
  • Inositol 1,4,5-Trisphosphate Receptors
  • Marine Toxins
  • Oxazoles / pharmacology
  • Potassium Iodide / pharmacology
  • Receptors, Cytoplasmic and Nuclear / analysis
  • Receptors, Cytoplasmic and Nuclear / metabolism*
  • Sarcoplasmic Reticulum Calcium-Transporting ATPases
  • TRPC Cation Channels
  • Type C Phospholipases / physiology

Substances

  • Actins
  • CAV1 protein, human
  • Calcium Channels
  • Caveolin 1
  • Caveolins
  • ITPR1 protein, human
  • Inositol 1,4,5-Trisphosphate Receptors
  • Marine Toxins
  • Oxazoles
  • Receptors, Cytoplasmic and Nuclear
  • TRPC Cation Channels
  • TRPC3 cation channel
  • Potassium Iodide
  • calyculin A
  • Type C Phospholipases
  • Sarcoplasmic Reticulum Calcium-Transporting ATPases
  • Calcium-Transporting ATPases
  • Calcium