Sigma-1 receptor

SIGMAR1
Available structures
PDB	Ortholog search: PDBe RCSB
List of PDB id codes
	5HK1, 5HK2, 6DJZ, 6DK0, 6DK1
Identifiers
Aliases	SIGMAR1, ALS16, OPRS1, SIG-1R, SR-BP, SR-BP1, SRBP, hSigmaR1, sigma1R, DSMA2, sigma non-opioid intracellular receptor 1
External IDs	OMIM: 601978; MGI: 1195268; HomoloGene: 39965; GeneCards: SIGMAR1; OMA:SIGMAR1 - orthologs
Gene location (Human)
Chr.	Chromosome 9 (human)
End	34,637,844 bp
Gene location (Mouse)
Chr.	Chromosome 4 (mouse)
End	41,756,157 bp
RNA expression pattern
	Top expressed in
	right lobe of liver; ; stromal cell of endometrium; ; right coronary artery; ; ectocervix; ; left uterine tube; ; right adrenal gland; ; right adrenal cortex; ; canal of the cervix; ; left adrenal gland; ; left coronary artery;
	Top expressed in
	left lobe of liver; ; tail of embryo; ; epiblast; ; lip; ; embryo; ; right kidney; ; yolk sac; ; embryo; ; superior frontal gyrus; ; primary visual cortex;
	More reference expression data
	n/a
Gene ontology
Molecular function	G protein-coupled opioid receptor activity; identical protein binding; signaling receptor activity;
Cellular component	postsynaptic membrane; cell projection; endoplasmic reticulum membrane; membrane; growth cone; lipid droplet; plasma membrane; synapse; integral component of plasma membrane; cell junction; nuclear inner membrane; nuclear outer membrane; nucleus; nuclear envelope; endoplasmic reticulum; integral component of membrane; cytoplasmic vesicle; postsynaptic density;
Biological process	lipid transport; regulation of neuron apoptotic process; nervous system development; G protein-coupled opioid receptor signaling pathway; protein homotrimerization; signal transduction; cell death in response to hydrogen peroxide;
	Sources:Amigo / QuickGO
Orthologs
	10280
	18391
	ENSG00000147955
	ENSMUSG00000036078
	Q99720
	O55242
NM_001282205; NM_001282206; NM_001282207; NM_001282208; NM_001282209;
	NM_005866; NM_147157; NM_147158; NM_147159; NM_147160
NM_011014; NM_001286538; NM_001286539; NM_001286540; NM_001286541;
	NM_001286542; NM_001286551; NM_001286605
NP_001269134; NP_001269135; NP_001269136; NP_001269137; NP_001269138;
	NP_005857; NP_671513
NP_001273467; NP_001273468; NP_001273469; NP_001273470; NP_001273471;
	NP_001273480; NP_001273534; NP_035144
	Wikidata
View/Edit Human	View/Edit Mouse

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. It has been implicated in several phenomena, including cardiovascular function, schizophrenia, clinical depression, the effects of cocaine abuse, bipolar disorder, and cancer. Much is known about the binding affinity of hundreds of synthetic compounds to the σ₁ receptor.

An endogenous ligand for the σ₁ receptor has yet to be conclusively identified, but tryptaminergic trace amines and neuroactive steroids have been found to activate the receptor. Especially progesterone, but also testosterone, pregnenolone sulfate, N,N-dimethyltryptamine (DMT) and dehydroepiandrosterone sulfate (DHEA-S) bind to the σ₁ receptor.