Translator Disclaimer
8 May 2017 Ca2+signaling machinery is present at intercellular junctions and structures associated with junction turnover in rat Sertoli cells
Kevin Lyon, Arlo Adams, Matthew Piva, Parisa Asghari, Edwin D. Moore, A. Wayne Vogl
Author Affiliations +
Abstract

The endoplasmic reticulum (ER) in Sertoli cells is a component of unique adhesion junctions (ectoplasmic specializations—ESs) and is closely associated with structures termed tubulobulbar complexes (TBCs) that internalize intercellular junctions during sperm release and during the translocation of spermatocytes through the blood-testis barrier. A role for the ER in Ca2+ regulation at ESs and TBCs has been suspected, but evidence for this function has proved elusive. Using electron microscopy, we define two new ER-plasma membrane (PM) contact sites in apical Sertoli cell processes. One of these sites occurs at TBCs where flattened lamellar cisternae of ER envelope the swollen bulb regions of the complexes, and where the gap between adjacent membranes is 12 nm. The other is at the periphery of apical processes where the gap between membranes is 13–14 nm. Using immunolocalization at the light and electron microscopic levels, we demonstrate that Ca2+ regulatory machinery is present at the ESs attached to spermatid heads, and at ER-PM contacts. Sarco/endoplasmic reticulum Ca2+-ATPase 2 (ATP2A2, SERCA2) is present at ESs; transient receptor potential channel subfamily M member 6 (TRPM6), Homer1 (HOMER1), and inositol 1,4,5-trisphosphate receptor (ITPR, IP3R) are present at ER-PM contacts associated with TBC bulbs; and stromal interacting molecule 1 (STIM1), Orai1 (ORAI1), and ATP2A2 are present at the ER-PM contacts around the margins of Sertoli cell apical processes. In Sertoli cells, the molecular machinery associated with ER generated Ca2+ fluxes is present in regions and structures directly related to junction remodeling—a process necessary for sperm release.

Summary Sentence

Calcium may be a regulator of junction turnover in rat testis.

© The Authors 2017. Published by Oxford University Press on behalf of Society for the Study of Reproduction. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com
Kevin Lyon, Arlo Adams, Matthew Piva, Parisa Asghari, Edwin D. Moore, and A. Wayne Vogl "Ca2+signaling machinery is present at intercellular junctions and structures associated with junction turnover in rat Sertoli cells," Biology of Reproduction 96(6), 1288-1302, (8 May 2017). https://doi.org/10.1093/biolre/iox042
Received: 28 March 2017; Accepted: 8 May 2017; Published: 8 May 2017
JOURNAL ARTICLE
15 PAGES

This article is only available to subscribers.
It is not available for individual sale.
+ SAVE TO MY LIBRARY

SHARE
ARTICLE IMPACT
RIGHTS & PERMISSIONS
Get copyright permission
Back to Top