^{1GDF15 for neuroprotection2017 · PMID 30650944Open reference}

GFRAL Protein (GDNF Receptor Alpha-Like)
Gene	[GFRAL](/genes/gfral)
UniProt	Q9GZD8
Alternative Names	GFRAL, GDNF family receptor alpha-like, GFRα3
Molecular Weight	~50 kDa
Subcellular Localization	Plasma membrane, Cytoplasm
Protein Family	GDNF receptor family (GFRα)
Associated Diseases	ALS, Als, Autoimmune, Cancer, Inflammation
KG Connections	49 edges

GFRAL Protein (GDNF Receptor Alpha-Like)

Introduction

Gfral Protein Gdnf Receptor Alpha Like 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

GFRAL (GDNF Receptor Alpha-Like) is a member of the GDNF (Glial Cell Line-Derived Neurotrophic Factor) receptor family. It was originally considered an orphan receptor but has emerged as a critical regulator of energy homeostasis and body weight through its interaction with the hormone GDF15 (Growth Differentiation Factor 15).^{2GDF15 is a stress response cytokine2016 · PMID 27260156Open reference}

While GFRAL does not directly bind GDNF, it is a high-affinity receptor for GDF15 and plays important roles in metabolic regulation that have implications for neurodegenerative diseases.^{3The GDF15-GFRAL pathway in metabolic disease2016 · PMID 27260157Open reference}

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Structure

Domain Architecture

GFRAL is a single-pass transmembrane receptor with:

• Extracellular Domain (1-400 aa): Contains multiple leucine-rich repeat (LRR) motifs and a C-terminal cysteine-rich domain (CRD) for ligand binding

• Transmembrane Domain (401-423 aa): Single pass α-helix spanning the plasma membrane

• Intracellular Domain (424-461 aa): Short cytoplasmic tail for signal transduction

Ligand Binding

GFRAL specifically binds:

• GDF15 (Growth Differentiation Factor 15): Primary ligand

• GDF15/GFRAL complex: Triggers retrograde signaling

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Normal Biological Function

Metabolic Regulation

1. Energy Homeostasis: GFRAL activation by GDF15 regulates food intake and energy expenditure

2. Body Weight Control: Central receptor for GDF15-mediated anorexigenic (appetite-suppressing) effects

3. Stress Response: GDF15-GFRAL axis is activated in response to mitochondrial stress, cellular damage, and inflammation

GDF15-GFRAL Signaling Pathway

1. GDF15 is secreted in response to cellular stress (mitochondrial dysfunction, ER stress, oxidative stress)

2. GDF15 binds to GFRAL on neurons in the area postrema and nucleus tractus solitarius

3. Activation triggers RET-independent signaling cascades

4. Results in reduced food intake, weight loss, and metabolic adaptation

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Role in Neurodegenerative Diseases

Parkinson’s Disease

The GDF15-GFRAL axis has significant implications for PD:

1. Mitochondrial Dysfunction: GDF15 is upregulated in response to mitochondrial stress in dopaminergic neurons

2. Neuroprotection: GDF15 can protect neurons from oxidative stress and apoptosis

3. Metabolic Links: GDF15 levels are altered in PD patients

4. Therapeutic Potential: GFRAL signaling may provide neuroprotective effects

Alzheimer’s Disease

1. Amyloid Stress: Aβ induces GDF15 expression in neurons

2. Inflammatory Response: GDF15 acts as a biomarker of cellular stress in AD

3. Metabolic Dysfunction: The GDF15-GFRAL axis may contribute to metabolic disturbances in AD

Amyotrophic Lateral Sclerosis

1. Motor Neuron Stress: GDF15 elevated in ALS patients and models

2. Muscle-GFRAL Signaling: May mediate muscle-nerve communication in disease

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GDF15 as a Biomarker

Diagnostic Value

• Parkinson’s Disease: GDF15 elevated in PD patients, correlates with disease severity

• Alzheimer’s Disease: Higher GDF15 levels associated with cognitive decline

• ALS: Strong predictor of disease progression

Prognostic Implications

Disease	GDF15 Level	Prognostic Value
PD	Elevated	Worse motor scores
AD	Elevated	Faster cognitive decline
ALS	Elevated	Shorter survival

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Therapeutic Implications

Targeting GFRAL Signaling

1. GFRAL Agonists: Recombinant GDF15 or GDF15 analogs for metabolic indications

2. GFRAL Antagonists: Blocking GFRAL to treat cachexia (wasting syndrome)

3. Neuroprotective Strategies: Enhancing GDF15-GFRAL signaling for neuroprotection

Challenges

• Complex tissue distribution

• Peripheral vs central nervous system effects

• Cross-talk with other neurotrophic factor pathways

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Interaction Network

GFRAL interacts with:

• GDF15: Primary ligand

• RET: Co-receptor for some GDNF family ligands (not GDF15)

• TROY: Alternative co-receptor

• SorCS2: VPS10P domain receptor

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Genetic Variants

Variant	Effect	Phenotype
rs9891289	Promoter variant	Altered GDF15 response
Rare loss-of-function	Truncation	Impaired metabolic response

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Background

The study of Gfral Protein Gdnf Receptor Alpha Like 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.

External Links

• UniProt: https://www.uniprot.org/uniprot/Q9GZD8

• NCBI Gene: https://www.ncbi.nlm.nih.gov/gene/440117

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See Also

• GFRAL Gene

• Parkinson’s Disease

• Alzheimer’s Disease

• Mitochondrial Dynamics Pathway

• GDF15 Biomarker