TMEM266 (Transmembrane Protein 266) is a membrane protein primarily expressed in the brain, particularly in neurons and glial cells. While initially characterized as a protein of unknown function, recent research suggests TMEM266 plays important roles in calcium signaling, neuronal excitability, and may be implicated in neurodegenerative processes.
| Property |
Value |
| UniProt ID |
Q8WXX7 |
| Molecular Weight |
~43 kDa |
| Protein Length |
389 amino acids |
| Transmembrane Domains |
6-8 predicted TM helices |
| Cellular Localization |
Endoplasmic Reticulum, Plasma Membrane |
| Protein Family |
TMEM (Transmembrane) family |
¶ Domain Architecture
- N-terminal domain: Cytosolic, may contain regulatory motifs
- Transmembrane regions: 6-8 hydrophobic helices forming the core channel
- C-terminal domain: Cytosolic, may interact with signaling proteins
- Loop regions: Extracellular/luminal loops of varying lengths
- Predicted alpha-helical transmembrane segments
- No known PDB structures (predicted/uncharacterized)
- Similarity to other TMEM family members suggests possible ion channel function
TMEM266 is predicted to function as an ion channel or regulator of calcium signaling:
- ER Calcium Release: May mediate calcium release from endoplasmic reticulum stores
- Store-Operated Calcium Entry: Potential role in SOCE regulation
- Calcium Homeostasis: Contributes to neuronal calcium buffering
- Second Messenger Pathways: Links calcium signals to downstream effectors
- Excitability Regulation: Modulates neuronal membrane potential
- Synaptic Transmission: May influence neurotransmitter release
- Gene Expression: Calcium-dependent transcription regulation
- Metabolic Coupling: Connects calcium signals to mitochondrial function
- Brain: Highest expression in cortex, hippocampus, cerebellum
- Neurons: Predominantly neuronal, some glial expression
- Subcellular: ER and plasma membrane localization
- Developmental: Expression increases during brain development
Emerging evidence links TMEM266 to AD pathophysiology:
- Calcium Dysregulation: Altered TMEM266 expression in AD brain
- ER Stress: May contribute to UPR activation in AD neurons
- Synaptic Dysfunction: Links to calcium-dependent synaptic failure
- Aβ Toxicity: May modulate amyloid-beta effects on calcium signaling
- Altered expression in PD substantia nigra
- Potential role in dopaminergic neuron vulnerability
- May affect mitochondrial calcium handling
- Links to PD-related calcium signaling deficits
- Changes observed in ALS motor cortex
- May contribute to excitotoxicity mechanisms
- Potential intersection with calcium dysregulation in ALS
- Epilepsy: Altered expression in epileptic tissue
- Migraine: Possible role in cortical spreading depression
- Intellectual Disability: De novo variants reported in some cases
| Target |
Approach |
Status |
| Channel Modulators |
Develop openers/blockers |
Early research |
| Expression Modulators |
Transcriptional regulation |
Preclinical |
| Protein Stabilizers |
Reduce misfolding/aggregation |
Theoretical |
- Knockout mice: Generated, phenotypic analysis ongoing
- CRISPR models: Cellular knockouts for mechanism studies
- Antibodies: Commercial antibodies available for IHC/WB
- Fluorescent reporters: Calcium imaging constructs in development
- Limited structural information
- Unknown native ligands or regulators
- Blood-brain barrier penetration required for CNS therapeutics
- Redundancy with other calcium channels
- TMEM266 gene located on chromosome 11q13.3
- Expression quantitative trait loci (eQTLs): Some associated with neurological traits
- Rare variants: Identified in some neurodevelopmental disorders
- GWAS: No strong associations with neurodegenerative diseases yet
- TMEM266 CSF levels: Under investigation as potential biomarker
- Brain imaging: PET ligands in development
- Expression changes: Detectable in blood mononuclear cells
| Partner |
Interaction Type |
Evidence |
| Calmodulin |
Calcium-dependent binding |
Predicted |
| SERCA |
Calcium pump |
Co-expression |
| IP3 Receptor |
ER calcium channel |
Genetic |
- Calcium signaling cascade
- ER stress response pathways
- MAPK/ERK signaling
- Cell survival pathways