Table of Contents
ISRN Cell Biology
Volume 2013, Article ID 237192, 13 pages
Review Article

A Microscopic View of the Store-Operated Calcium Entry-Pathway

Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico, DF 04510, Mexico

Received 30 August 2013; Accepted 24 September 2013

Academic Editors: S. Bruzzone and M. Estrada

Copyright © 2013 Jonathan Pacheco and Luis Vaca. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Orai and STIM are the basic components of a highly complex and regulated mechanism for Ca2+ entry into the cell, known as store-operated calcium entry (SOCE). The activation of plasma membrane G-protein-coupled receptors associated with the phospholipase C cascade results in the rapid and massive production of inositol 1,4,5-triphosphate (IP3). This second messenger triggers the massive efflux of Ca2+ from the endoplasmic reticulum and into the cytosol, resulting in the oligomerization of the stromal interacting molecule (STIM1), a sensor of ER Ca2+. STIM1 oligomers (the so-called puncta) activate Orai channels at the plasma membrane, triggering the influx of Ca2+ into the cytosol. Several microscopy techniques have been implemented to study SOCE, resulting in stunning images of protein complexes assembling in real time. However, little attention has been paid to the findings about this complex mechanism from the imaging point of view, some of which appear to produce contradictory results. In the present review we gathered all the information about SOCE obtained with imaging techniques and contrast these findings with those obtained with alternative methods.