Seroatlas · Human Serome Atlas

SIGMAR1

Sigma non-opioid intracellular receptor 1

Also known as: OPRS1, SGMR1_HUMAN, SR-BP1

Cross-references: UniProt · Ensembl · Human Protein Atlas · GeneCards · NCBI Gene

Protein identityUniProt · HPA

UniProt accession
Q99720
Gene
SIGMAR1
Ensembl
ENSG00000147955
Chromosome
9
Canonical length
223 aa
Protein class
Disease related genes, FDA approved drug targets, Human disease related genes, Predicted intracellular proteins, Predicted membrane proteins, Transporters
Quaternary structure
Homotrimer

OverviewNCBI Gene

This gene encodes a receptor protein that interacts with a variety of psychotomimetic drugs, including cocaine and amphetamines. The receptor is believed to play an important role in the cellular functions of various tissues associated with the endocrine, immune, and nervous systems. As indicated by its previous name, opioid receptor sigma 1 (OPRS1), the product of this gene was erroneously thought to function as an opioid receptor; it is now thought to be a non-opioid receptor. Mutations in this gene has been associated with juvenile amyotrophic lateral sclerosis 16. Alternative splicing of this gene results in transcript variants encoding distinct isoforms. [provided by RefSeq, Aug 2013]

Canonical amino-acid sequenceUniProt

223 residues, UniProt reviewed canonical sequence.

>Q99720|SIGMAR1
     1  MQWAVGRRWA WAALLLAVAA VLTQVVWLWL GTQSFVFQRE EIAQLARQYA GLDHELAFSR
    61  LIVELRRLHP GHVLPDEELQ WVFVNAGGWM GAMCLLHASL SEYVLLFGTA LGSRGHSGRY
   121  WAEISDTIIS GTFHQWREGT TKSEVFYPGE TVVHGPGEAT AVEWGPNTWM VEYGRGVIPS
   181  TLAFALADTV FSTQDFLTLF YTLRSYARGL RLELTTYLFG QDP

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against SIGMAR1 can act on the native protein depends on physical access: surface and secreted proteins are reachable by circulating antibodies, intracellular proteins usually are not.

Antibody reachability
Cell surface
Secreted
No
Transmembrane segments
1
Mean surface accessibility (rSASA)
0.29
Highest tissue expression
168 nTPM

Expression across tissuesHPA

Tissue

  • liver: 168 nTPM
  • esophagus: 48 nTPM
  • skin: 48 nTPM
  • blood vessel: 46 nTPM
  • adrenal gland: 46 nTPM
  • endometrium: 44 nTPM

Single-cell type

  • extravillous trophoblasts: 112 nCPM
  • hepatocytes: 108 nCPM
  • esophageal basal cells: 96 nCPM
  • migrating cytotrophoblasts: 84 nCPM
  • esophageal suprabasal cells: 61 nCPM
  • enteric transient amplifying cells: 61 nCPM

Immune cell

  • T-reg: 66 nTPM
  • memory CD4 T-cell: 63 nTPM
  • naive CD4 T-cell: 52 nTPM
  • memory CD8 T-cell: 51 nTPM
  • myeloid DC: 49 nTPM
  • MAIT T-cell: 46 nTPM

Brain region

  • hypothalamus: 42 nTPM
  • pons: 35 nTPM
  • midbrain: 33 nTPM
  • medulla oblongata: 32 nTPM
  • choroid plexus: 30 nTPM
  • white matter: 30 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about SIGMAR1.

Disease | AllUniProt

Conditions SIGMAR1 is implicated in, by any mechanism.

  • Amyotrophic lateral sclerosis 16, juvenile (ALS16) MIM:614373
  • Neuronopathy, distal hereditary motor, autosomal recessive 2 (HMNR2) MIM:605726

Disease | GeneticClinVar

27 pathogenic / likely-pathogenic of 229 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

Genetic constraint and essentialitygnomAD · DepMap

Does the body need this protein intact? Low LOEUF or a strong DepMap dependency means loss or blockade of the protein is likely to be felt.

gnomAD LOEUF (loss-of-function intolerance)
0.74
gnomAD pLI
0.17
gnomAD missense Z
1.46
DepMap mean gene effect
-0.21
DepMap dependency class
selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 7% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

Molecular functions

Cellular components

Protein domainsUniProt · Pfam · InterPro

  • ERG2/sigma1 receptor-like
  • ERG2 and Sigma1 receptor like protein

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of SIGMAR1 in the human serome: UniProt-annotated complex subunits plus reported interactors. Each links to its own Seroatlas record.

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads SIGMAR1 as an antibody target. Whether an autoantibody or antibody against SIGMAR1 could matter depends on whether native SIGMAR1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

SIGMAR1 is annotated at the cell surface, where native SIGMAR1 is exposed to circulating antibodies and is a prime autoantibody target that could block, deplete, or overstimulate it.

Annotation status

The present source text does not explicitly label SIGMAR1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/SIGMAR1. Study-independent annotations aggregated from UniProt, Human Protein Atlas, PubMed, IEDB, Pfam, InterPro, Gene Ontology, AlphaFold, gnomAD, DepMap, ClinVar, TCGA. Catalog release seroatlas-reviewed-human-uniprot-20260313.

Seroatlas is the reference for exploring autoantibody and antibody serology at the human-protein level: the autoreactome and human serome, multiplex serology (HuProt, HuScan, VirScan, PhIP-Seq).

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