ORAI Channels in Vascular Smooth Muscle

Maxime Guéguinou, Xuexin Zhang, Trayambak Pathak, Scott Emrich, Ryan Yoast, Mohamed Trebak

Research output: Chapter in Book/Report/Conference proceedingChapter


This chapter describes how to study the activities of the ORAI channels in synthetic Vascular Smooth Muscles (VSMCs). Using optical and electrophysiological methods, ORAI channel activity is essentially undetected in quiescent VSMCs but becomes prominent in synthetic VSMCs. In quiescent VSMCs, the expression of ORAI and STIM proteins is either very low or absent and pharmacological store depletion failed to activate store-operated Ca2+ entry (SOCE). In contrast, ORAI1 and STIM1 are upregulated in synthetic VSMCs, which are found in diseases of vessel remodeling. Atomic resolution structures of mammalian ORAI isoforms are currently undefined, but based on the drosophila structure and studies using concatenated oligomers of ORAI1, functional mammalian ORAI channels are likely hexamers. The SOCE current mediated by ORAI1 channels is termed the Ca2+ release-activated Ca2+ current. The most common Ca2+ indicator used to measure global cytosolic Ca2+ signals generated by the SOCE pathway is the indicator Fura2, originally developed by RY Tsien and collaborators.

Original languageEnglish (US)
Title of host publicationSignal Transduction and Smooth Muscle
PublisherCRC Press
Number of pages13
ISBN (Electronic)9781498774239
ISBN (Print)9781498774222
StatePublished - Jan 1 2018

All Science Journal Classification (ASJC) codes

  • General Biochemistry, Genetics and Molecular Biology
  • General Agricultural and Biological Sciences


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