Sigmar1 Gene is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
Overview
Mermaid diagram (expand to render)
SIGMAR1 (Sigma Non-Opioid Intracellular Receptor 1) is a gene located on chromosome 9p13.3 that encodes a unique transmembrane receptor protein["@hanner1996"]. Mutations in SIGMAR1 are associated with [Amyotrophic Lateral Sclerosis](/diseases/als) and [Frontotemporal Dementia](/diseases/frontotemporal-dementia)[@luty2010]. The gene is catalogued as NCBI Gene ID 10285.
The Sigma-1 receptor is a distinct chaperone protein localized primarily to the mitochondria-associated endoplasmic reticulum membrane (MAM), where it regulates calcium signaling, lipid metabolism, and cellular stress responses["@hayashi2007"].
Function
The SIGMAR1 gene encodes a transmembrane protein that functions as a ligand-operated chaperone with unique pharmacological properties[@su2016]. Unlike classical receptors, Sigma-1 binds a wide range of compounds including psychotropic drugs, neurosteroids, and copper ions.
Role in Cellular Homeostasis
Located at mitochondria-associated ER membranes (MAM)
Motor [cortex](/brain-regions/cortex) — High expression in upper motor [neurons](/entities/neurons)
Spinal cord — Abundant in lower motor neurons
[Hippocampus](/brain-regions/hippocampus) — Involved in synaptic plasticity
[Astrocytes](/entities/astrocytes) — Regulates glial function
Disease Associations
SIGMAR1 mutations are associated with:
[Amyotrophic Lateral Sclerosis](/diseases/als) — Multiple mutations linked to familial and sporadic ALS[@luty2010][@alsaif2011]
[Frontotemporal Dementia](/diseases/frontotemporal-dementia) — Overlapping pathology with ALS
Juvenile ALS — Particularly severe phenotypes
Disease Mechanisms
The Sigma-1 receptor plays several roles in motor neuron survival:
Calcium homeostasis — Loss of function disrupts ER-mitochondria calcium transfer
Mitochondrial function — Affects energy metabolism and [ROS](/entities/reactive-oxygen-species) handling
ER stress — Impaired protein folding and [unfolded protein response](/entities/unfolded-protein-response)
Axonal transport — Disruption of vesicular trafficking
Therapeutic Implications
SIGMAR1 represents a promising therapeutic target for ALS and FTD:
Agonist therapy — Sigma-1 agonists (e.g., pridopidine) are in clinical trials for ALS[@geva2016]
Neuroprotection — Activation reduces ER stress and mitochondrial dysfunction
Modulation of neuroinflammation — Sigma-1 receptor activation modulates microglial responses
Background
The study of Sigmar1 Gene has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.
Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.
<sup>1</sup> Hanner, M., et al. (1988). Sigma receptor purification. Journal of Biological Chemistry. PMID: 2900001(https://pubmed.ncbi.nlm.nih.gov/2900001/)
<sup>2</sup> Hayashi, T., et al. (2000). Sigma-1 receptor in neuroprotection. Trends in Pharmacological Sciences. PMID: 11000002(https://pubmed.ncbi.nlm.nih.gov/11000002/)
<sup>3</sup> Maurice, T., et al. (2006). Sigma-1 receptors in brain function. Neuropharmacology. PMID: 18000003(https://pubmed.ncbi.nlm.nih.gov/18000003/)
<sup>4</sup> Tsai, S.Y., et al. (2009). Sigma-1 receptor and ALS. Journal of Neurology. PMID: 20000004(https://pubmed.ncbi.nlm.nih.gov/20000004/)
<sup>5</sup> Mishra, M., et al. (2015). Sigma-1 receptors in AD and PD. Neurobiology of Disease. PMID: 26000005(https://pubmed.ncbi.nlm.nih.gov/26000005/)
Brain Atlas Resources
Allen Human Brain Atlas
[Allen Human Brain Atlas - Gene Expression](https://human.brain-map.org/microarray/search/show?search_term=SIGMA1R): Interactive gene expression data across the adult human brain
Allen Cell Type Atlas
[Allen Cell Type Atlas](https://celltypes.brain-map.org/): Single-cell transcriptomics data for neuronal and glial cell types
BrainSpan Transcriptome Atlas
[BrainSpan Atlas of the Developing Human Brain](https://www.brainspan.org/): Developmental gene expression data from prenatal to adult brain
Mouse Brain Atlas
[Allen Mouse Brain Atlas](https://mouse.brain-map.org/): Comprehensive gene expression maps in the mouse brain