Tags: Protein.
The sigma-1 receptor (σ1R) one of two sigma receptor subtypes is a chaperone protein at the Endoplasmic reticulum (ER) that modulates calcium signaling through the IP3 receptor. In humans the σ1 receptor is encoded by the SIGMAR1 gene.The σ1 receptor is a transmembrane protein expressed in many different tissue types. It is particularly concentrated in certain regions of the central nervous system.