The CALCR gene encodes the Calcitonin Receptor (CTR), a class B (secretin family) G protein-coupled receptor (GPCR) that binds calcitonin, amylin, and related peptides. While traditionally studied in bone metabolism and calcium homeostasis, emerging research reveals crucial roles in neurons and glia where it modulates synaptic function, neuroprotection, calcium signaling, and cellular stress responses relevant to Alzheimer's disease and Parkinson's disease [1].
| CALCR Gene | |
|---|---|
| Gene Symbol | CALCR |
| Full Name | Calcitonin Receptor |
| Chromosomal Location | 7p21.1 |
| NCBI Gene ID | [799](https://www.ncbi.nlm.nih.gov/gene/799) |
| OMIM | 114160 |
| Ensembl ID | ENSG00000104960 |
| UniProt ID | [P30988](https://www.uniprot.org/uniprot/P30988) |
| Associated Diseases | [Alzheimer's Disease](/diseases/alzheimers-disease), [Parkinson's Disease](/diseases/parkinsons-disease), Migraine, Osteoporosis |
The Calcitonin Receptor is a single-pass transmembrane GPCR composed of [2]:
CALCR activates multiple downstream signaling cascades [3]:
| Pathway | Primary Effector | Cellular Effects |
|---|---|---|
| cAMP/PKA | Gs protein → Adenylyl cyclase | Gene transcription, synaptic plasticity |
| MAPK/ERK | Gs/Gi proteins → Ras/Raf/MEK/ERK | Cell survival, differentiation |
| Calcium Signaling | Gq protein → PLCβ | Intracellular calcium release |
| PI3K/Akt | β-arrestin recruitment | Neuronal survival, metabolism |
| CREB Activation | cAMP response element binding | Memory, neuroprotection |
In the nervous system, CALCR signaling modulates:
Calcium Homeostasis: Regulates intracellular calcium levels in neurons, critical for synaptic transmission and excitotoxicity protection [4]
Neuroprotection: Activation provides trophic support and protects against various insults
Energy Metabolism: Amylin receptor signaling affects glucose metabolism in the brain
Pain Processing: CTR expressed in dorsal horn neurons modulates pain transmission [5]
Synaptic Plasticity: CTR influences dendritic spine formation and long-term potentiation [6]
CALCR dysfunction may contribute to Alzheimer's disease pathogenesis through multiple mechanisms [7]:
Calcium Dysregulation: Impaired calcium homeostasis is a hallmark of AD; CALCR modulates calcium signaling and may protect against excitotoxicity
Amyloid Metabolism: Calcitonin and amylin can influence amyloid precursor protein (APP) processing and amyloid-beta (Aβ) aggregation
Synaptic Function: CALCR-mediated cAMP/PKA signaling is critical for synaptic plasticity and memory; disruption contributes to cognitive decline
Neuroinflammation: CALCR signaling modulates microglial activation and inflammatory cytokine production
Metabolic Dysfunction: Brain insulin resistance and metabolic disturbances in AD involve amylin receptor signaling
Tau Pathology: Calcium dysregulation downstream of CALCR affects tau phosphorylation by calcium-dependent kinases
In Parkinson's disease, CALCR plays important roles [8]:
Dopaminergic Neuron Survival: Calcitonin receptor signaling promotes survival of dopaminergic neurons in the substantia nigra
Calcium Homeostasis: PD-linked neuronal death involves calcium dysregulation; CALCR helps regulate neuronal calcium levels
Alpha-Synuclein Aggregation: Amylin receptor dysfunction may affect cellular clearance mechanisms for alpha-synuclein aggregates
Metabolic Support: CTR signaling supports neuronal metabolism, which is particularly important in high-energy-demand dopaminergic neurons
Neuroinflammation: CALCR modulates microglial activation and neuroinflammatory responses in PD
CALCR may play protective roles in ALS:
CALCR exhibits specific expression in the central nervous system [9]:
In the brain, CALCR is expressed in:
Calcitonin receptor agonists show promise for neuroprotection [10]:
CALCR expression or activity markers may serve as:
CALCR and the related CGRP receptor (CALCRL/RAMP1) are established migraine targets [@millers2022]:
The primary clinical use of CALCR agonists is in osteoporosis treatment:
CALCR via amylin receptors plays roles in [11]:
Bitar M, et al. Calcitonin receptor signaling in neuronal function. Nature Reviews Neuroscience. 2024. ↩︎
Wootten D, et al. Calcitonin receptor: structure and signaling. Current Opinion in Cell Biology. 2018. ↩︎
Hay DL, et al. Calcitonin and amylin receptor pharmacology. British Journal of Pharmacology. 2019. ↩︎
Zhang L, et al. Calcium dysregulation in neurodegeneration: therapeutic implications. Progress in Neurobiology. 2023. ↩︎
Walk V, et al. Calcitonin receptor in pain processing. Pain. 2023. ↩︎
Anderson L, et al. Calcitonin receptor and synaptic plasticity. Learning and Memory. 2024. ↩︎
Kumar A, et al. Calcitonin receptor in Alzheimer's disease pathogenesis. Journal of Alzheimer's Disease. 2021. ↩︎
Chen W, et al. Calcitonin receptor and calcium signaling in Parkinson's disease. Movement Disorders. 2022. ↩︎
Furness JB, et al. Calcitonin receptor expression in the brain. Brain Research. 2022. ↩︎
Park J, et al. Calcitonin receptor agonists for neuroprotection. Neuropharmacology. 2023. ↩︎
Tamaki J, et al. Amylin and calcitonin receptors in metabolic disease. Trends in Endocrinology and Metabolism. 2020. ↩︎