Homeostatic regulation of the PI(4,5)P2-Ca2+ signaling system at ER-PM junctions

Chi Lun Chang, Jen Liou

Research output: Contribution to journalArticle

23 Scopus citations

Abstract

The phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2)-Ca2+ signaling system is important for cell activation in response to various extracellular stimuli. This signaling system is initiated by receptor-induced hydrolysis of PI(4,5)P2 in the plasma membrane (PM) to generate the soluble second messenger inositol 1,4,5-trisphosphate (IP3). IP3 subsequently triggers the release of Ca2+ from the endoplasmic reticulum (ER) store to the cytosol to activate Ca2+-mediated responses, such as secretion and proliferation. The consumed PM PI(4,5)P2 and ER Ca2+ must be quickly restored to sustain signaling responses, and to maintain the homeostasis of PI(4,5)P2 and Ca2+. Since phosphatidylinositol (PI), the precursor lipid for PM PI(4,5)P2, is synthesized in the ER membrane, and a Ca2+ influx across the PM is required to refill the ER Ca2+ store, efficient communications between the ER and the PM are critical for the homeostatic regulation of the PI(4,5)P2-Ca2+ signaling system. This review describes the major findings that established the framework of the PI(4,5)P2-Ca2+ signaling system, and recent discoveries on feedback control mechanisms at ER-PM junctions that sustain the PI(4,5)P2-Ca2+ signaling system. Particular emphasis is placed on the characterization of ER-PM junctions where efficient communications between the ER and the PM occur, and the activation mechanisms of proteins that dynamically localize to ER-PM junctions to provide the feedback control during PI(4,5)P2-Ca2+ signaling, including the ER Ca2+ sensor STIM1, the extended synaptotagmin E-Syt1, and the PI transfer protein Nir2. This article is part of a Special Issue entitled: The cellular lipid landscape edited by Tim Levine and Anant K. Menon.

Original languageEnglish (US)
JournalBiochimica et Biophysica Acta - Molecular and Cell Biology of Lipids
DOIs
StateAccepted/In press - Dec 10 2015

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Keywords

  • ER-PM junctions
  • ESyt1
  • Nir2
  • PI cycle
  • PI(4,5)P-Ca signaling
  • SOCE

ASJC Scopus subject areas

  • Cell Biology
  • Molecular Biology

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