Trpm7 Protein — Trp Cation Channel M7 is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
| Attribute |
Value |
| Protein Name |
TRPM7 (Transient Receptor Potential Cation Channel M7) |
| Gene |
TRPM7 |
| UniProt ID |
Q9BXZ4 |
| Molecular Weight |
~213 kDa (2035 amino acids) |
| Subcellular Localization |
Plasma membrane, intracellular vesicles |
| Protein Family |
TRPM (Melastatin) family |
| Channel Type |
Non-selective cation channel |
| Ion Permeability |
Ca²⁺, Mg²⁺, Zn²⁺, Mn²⁺, Ni²⁺ |
TRPM7 is a bifunctional protein with unique architecture:
¶ Channel Domain
- 6 transmembrane domains (S1-S6): Form the ion channel pore
- TRP domain: Conserved feature of TRP channels
- Pore loop: Between S5 and S6, forms selectivity filter
- N-terminal cytosolic domain: Multiple MHR (MELASTATIN homology repeat) domains
- N-terminal domain length: ~700 amino acids
¶ Kinase Domain
- C-terminal alpha-kinase: ~310 amino acids
- Serine/threonine specificity: Autophosphorylation sites
- Unique among TRP channels: TRPM7 and TRPM6 are the only ones with kinases
- Substrate binding pocket: Catalytic core
- Forms homomeric channels (functional)
- May form heteromers with TRPM6 in some tissues
- Channel assembly in endoplasmic reticulum
TRPM7 has dual functions as both ion channel and kinase:
| Property |
Description |
| Gating |
Constitutively open (voltage-independent) |
| Conductance |
~40 pS for Ca²⁺ |
| Selectivity |
PCa/PNa ~3.5 |
| Regulation |
pH, Mg²⁺, ATP, oxidative stress |
Physiological Roles:
- Magnesium homeostasis: Major Mg²⁺ influx pathway
- Calcium signaling: Supplies Ca²⁺ for cellular responses
- Zinc homeostasis: Regulates neuronal Zn²⁺
- Oxidative stress response: Activated by ROS/RNS
Autophosphorylation:
- Multiple serine/threonine sites
- Required for full channel activity
- Regulated by Mg²⁺ and ATP
Substrate Phosphorylation:
- Myosin IIA: Cytoskeleton regulation
- Annexin-1: Anti-inflammatory signaling
- TRPM7 itself: Autoregulation
- Translation elongation factor eEF2
Dysregulated in motor neurons:
- Contributes to excitotoxicity
- Alters Mg²⁺ homeostasis
- May interact with ALS proteins (SOD1, FUS, TDP-43)
- Channel dysfunction leads to:
- Impaired calcium buffering
- Increased excitotoxicity
- Motor neuron death
Changed expression in AD brain:
- Contributes to calcium dysregulation
- May enhance Aβ toxicity
- Kinase domain may phosphorylate tau
- Synaptic dysfunction through Ca²⁺ dysregulation
- Links to synaptic vesicle cycling
Involved in dopaminergic neuron survival:
- Manganese (Mn²⁺) neurotoxicity: Enters via TRPM7
- Links metal exposure to PD risk
- May affect alpha-synuclein aggregation
- Dopamine oxidation interacts with channel
- Vulnerability of SNc neurons
| Condition |
TRPM7 Role |
| Stroke/ischemia |
Mediates anoxic neuronal death |
| Epilepsy |
Altered function in seizures |
| Multiple Sclerosis |
Regulates myelin repair |
| Migraine |
Trigeminal pain signaling |
| Traumatic brain injury |
Contributes to secondary damage |
| Approach |
Compound |
Status |
Notes |
| Channel blockers |
2-APB |
Research |
Non-specific |
| Channel blockers |
FTY720 |
Preclinical |
FDA-approved for MS |
| Kinase inhibitors |
沉默 |
Research |
Specificity issues |
| Mg²⁺ supplementation |
Mg²⁺ |
Clinical |
May normalize function |
- Constitutive activity makes inhibition difficult
- Ubiquitous expression causes side effects
- Channel and kinase domains can be independent
- Blood-brain barrier penetration needed
TRPM7 interacts with:
- TRPM6: Heteromer formation (kidney, some neurons)
- Myosin IIA: Phosphorylation substrate
- Annexin-1: Anti-inflammatory effects
- SRC kinase: Regulatory phosphorylation
- PLC: Gq-coupled receptor regulation
TRPM7 is expressed in:
- Brain (highest): neurons, glia
- Heart, kidney, lung
- Immune cells (T cells, macrophages)
- Cancer cell lines
In brain:
- Cerebral cortex (pyramidal neurons)
- Hippocampus (CA1, dentate gyrus)
- Substantia nigra pars compacta
- Cerebellar Purkinje cells
- Spinal cord motor neurons
- Nadler MJ, et al. (2001). LTRPC7 is a Mg.ATP-regulated magnesium channel. Nature.[1]
- Sun HS, et al. (2019). TRPM7 in neurodegeneration. Cell Calcium.[2]
- Chokshi RH, et al. (2012). TRPM7 and brain ischemia. J Cereb Blood Flow Metab.[3]
- Jiang J, et al. (2019). TRPM7 in ALS pathogenesis. Acta Neuropathol Commun.[4]
- Zhao Y, et al. (2020). TRPM7 and Alzheimer's disease. Neurobiol Aging.[5]
TRPM7 has unique selectivity profile:
- Highly permeable to Mg²⁺ (PCa/Mg ~0.9)
- Moderate Ca²⁺ permeability
- Permeable to Zn²⁺ and other transition metals
- Monovalent cation permeation (Na⁺, K⁺)
TRPM7 activity is regulated by:
- Intracellular Mg²⁺ and ATP (inhibition)
- Oxidative stress (activation)
- pH changes
- Mechanical stimuli
- Phosphorylation state
¶ Kinase Domain
The alpha-kinase domain (aa 1563-1828):
- Serine/threonine specificity
- Autophosphorylation capability
- Substrate diversity
- Drug target potential
- Motor neuron sensitivity to TRPM7 dysregulation
- Magnesium homeostasis disruption
- Calcium-mediated excitotoxicity
- Oxidative stress amplification
- Aβ-induced TRPM7 alterations
- Calcium dysregulation
- Energy metabolism impairment
- Neuronal viability impact
- Dopaminergic neuron vulnerability
- Manganese toxicity mediation
- Cellular energy crisis
- Alpha-synuclein interactions
TRPM7 is dysregulated in various cancers:
- Promotes metastasis
- Cell migration
- Invasion capability
- Therapeutic target potential
| Strategy |
Agent |
Development Stage |
| Kinase inhibitors |
TPEN |
Preclinical |
| Channel blockers |
LaCl₃ |
Preclinical |
| Mg²⁺ supplementation |
Mg²⁺ |
Supportive |
| Anti-inflammatory |
Various |
Research |
- Whole-cell patch clamp
- Inside-out patches
- Noise analysis
- Current-voltage relationships
- Site-directed mutagenesis
- Channel chimeras
- Knockdown/knockout studies
- Transgenic models
The study of Trpm7 Protein — Trp Cation Channel M7 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.
[1] Nadler MJ, et al. LTRPC7 is a Mg.ATP-regulated magnesium channel. Nature. 2001;411(6837):590-595.
[2] Sun HS, et al. TRPM7 in neurodegeneration. Cell Calcium. 2019;80:38-47.
[3] Chokshi RH, et al. TRPM7 and brain ischemia. J Cereb Blood Flow Metab. 2012;32(12):e1-e10.
[4] Jiang J, et al. TRPM7 in ALS pathogenesis. Acta Neuropathol Commun. 2019;7(1):144.
[5] Zhao Y, et al. TRPM7 and Alzheimer's disease. Neurobiol Aging. 2020;94:233-245.