The sigma-1 receptors bind diverse kinds of psychoactive compounds, including @entity2072 , and translocate upon stimulation by these compounds. However, the exact intracellular localization and dynamics of sigma-1 receptors have been unclear. We recently found that sigma-1 receptors specifically localize on @entity165 -enriched loci on the endoplasmic reticulum (ER) membrane that function as neutral lipid storage sites (i.e., ER lipid droplets or ER-LDs) from which neutral lipids bud out to form cytosolic lipid droplets. By combining immunocytochemistry and real-time monitoring of enhanced yellow fluorescent protein (EYFP)-tagged sigma-1 receptors (Sig-1R-EYFP) in living cells, we characterized the @entity37021 translocation in this study. @entity12586 , a selective @entity37021 agonist, causes a significant decrease of sigma-1 receptors in ER-LDs and a diffused distribution of sigma-1 receptors over the entire endoplasmic reticulum reticular network in @entity19 cells. In the presence of @entity37021 agonists, Sig-1R-EYFP move out from ER-LDs and slide along the endoplasmic reticulum network toward nuclear envelope and the @entity527 . Fluorescence recovery after photobleaching analysis demonstrates that Sig-1R-EYFP on endoplasmic reticulum reticular network are highly mobile compared with those in ER-LDs. A sucrose gradient fractionation study shows that @entity12586 shifts sigma-1 receptors from ER-LD membranes to higher density membranes. These results indicate that sigma-1 receptors localize on ER-LDs and upon stimulation translocate on continuous endoplasmic reticulum reticular network toward peripheries of cells. Because sigma-1 receptors specifically target ER lipid storage sites and compartmentalize neutral lipids therein, these results suggest that sigma-1 receptors' dynamic translocation might affect lipid transport and distribution in neuronal cells.

Intracellular dynamics of sigma-1 receptors (sigma(1) binding sites) in XXXX cells.

@entity12586 :: ('MESH:D010423', 'Chemical') :: ['(+)-pentazocine', '(+)-Pentazocine'] @entity527 :: ('MESH:D058225', 'Disease') :: ['tip of neurites'] @entity19 :: ('10090', 'Species') :: ['NG108-15'] @entity2072 :: ('MESH:D003042', 'Chemical') :: ['cocaine'] @entity37021 :: ('18391(Tax:10090)', 'Gene') :: ['sigma-1 receptor'] @entity165 :: ('MESH:D002784', 'Chemical') :: ['cholesterol']
@entity19 :: (10090,Species) :: ['NG108-15']
