Role of lipid rafts in the interaction between hTRPC1, Orai1 and STIM1

Channels (Austin). 2008 Nov-Dec;2(6):401-3. doi: 10.4161/chan.2.6.7055. Epub 2008 Nov 23.

Abstract

Store-operated Ca2+ entry (SOCE) is a mechanism regulated by the filling state of the intracellular Ca2+ stores that requires the participation of the Ca2+ sensor STIM1, which communicates the Ca2+ content of the stores to the plasma membrane Ca2+-permeable channels. We have recently reported that Orai1 mediates the communication between STIM1 and the Ca2+ channel hTRPC1. This event is important to confer hTRPC1 store depletion sensitivity, thus supporting the functional role of the STIM1-Orai1-hTRPC1 complex in the activation of SOCE. Here we have explored the relevance of lipid rafts in the formation of the STIM1-Orai1-hTRPC1 complex and the activation of SOCE. Disturbance of lipid raft domains, using methyl-beta-cyclodextrin, reduces the interaction between endogenously expressed Orai1 and both STIM1 and hTRPC1 upon depletion of the intracellular Ca2+ stores and attenuates thapsigargin-evoked Ca2+ entry. These findings suggest that TRPC1, Orai1 and STIM1 form a heteromultimer associated with lipid raft domains and regulated by the intracellular Ca2+ stores.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Calcium / metabolism
  • Calcium Channels / metabolism*
  • Humans
  • Membrane Microdomains* / chemistry
  • Membrane Microdomains* / metabolism
  • Membrane Proteins / metabolism*
  • Multiprotein Complexes / metabolism
  • Neoplasm Proteins / metabolism*
  • ORAI1 Protein
  • Protein Binding
  • Stromal Interaction Molecule 1
  • TRPC Cation Channels / metabolism*

Substances

  • Calcium Channels
  • Membrane Proteins
  • Multiprotein Complexes
  • Neoplasm Proteins
  • ORAI1 Protein
  • ORAI1 protein, human
  • STIM1 protein, human
  • Stromal Interaction Molecule 1
  • TRPC Cation Channels
  • transient receptor potential cation channel, subfamily C, member 1
  • Calcium