Blog
About

  • Record: found
  • Abstract: found
  • Article: not found

Polyunsaturated fatty acids inhibit stimulated coupling between the ER Ca(2+) sensor STIM1 and the Ca(2+) channel protein Orai1 in a process that correlates with inhibition of stimulated STIM1 oligomerization.

Read this article at

ScienceOpenPublisherPMC
Bookmark
      There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

      Abstract

      Polyunsaturated fatty acids (PUFAs) have been found to be effective inhibitors of cell signaling in numerous contexts, and we find that acute addition of micromolar PUFAs such as linoleic acid effectively inhibit of Ca(2+) responses in mast cells stimulated by antigen-mediated crosslinking of FcεRI or by the SERCA pump inhibitor, thapsigargin. In contrast, the saturated fatty acid, stearic acid, with the same carbon chain length as linoleic acid does not inhibit these responses. Consistent with this inhibition of store-operated Ca(2+) entry (SOCE), linoleic acid inhibits antigen-stimulated granule exocytosis to a similar extent. Using the fluorescently labeled plasma membrane Ca(2+) channel protein, AcGFP-Orai1, together with the labeled ER Ca(2+) sensor protein, STIM1-mRFP, we monitor stimulated coupling of these proteins that is essential for SOCE with a novel spectrofluorimetric resonance energy transfer method. We find effective inhibition of this stimulated coupling by linoleic acid that accounts for the inhibition of SOCE. Moreover, we find that linoleic acid induces some STIM1-STIM1 association, while inhibiting stimulated STIM1 oligomerization that precedes STIM1-Orai1 coupling. We hypothesize that linoleic acid and related PUFAs inhibit STIM1-Orai1 coupling by a mechanism that involves perturbation of ER membrane structure, possibly by disrupting electrostatic interactions important in STIM1 oligomerization. Thisarticle is part of a Special Issue entitled Tools to study lipid functions.

      Related collections

      Author and article information

      Affiliations
      [1 ] Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, NY 14853, USA. Electronic address: dah24@cornell.edu.
      [2 ] Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, NY 14853, USA.
      Journal
      Biochim. Biophys. Acta
      Biochimica et biophysica acta
      Elsevier BV
      0006-3002
      0006-3002
      Aug 2014
      : 1841
      : 8
      24769339 S1388-1981(14)00081-X 10.1016/j.bbalip.2014.04.006 4069244 NIHMS589567

      Comments

      Comment on this article