GPX4 Gene - Glutathione Peroxidase 4

Introduction

Pathway Diagram

flowchart TD
    GPX4["GPX4<br/>Glutathione Peroxidase 4"]
    SLC7A11["SLC7A11<br/>Cystine/Glutamate<br/>Antiporter"]
    AUTOPHAGY["AUTOPHAGY<br/>Cellular Degradation<br/>Pathway"]
    FERROPTOSIS["FERROPTOSIS<br/>Iron-dependent<br/>Cell Death"]
    REDOX_HOMEOSTASIS["REDOX HOMEOSTASIS<br/>Cellular Antioxidant<br/>Balance"]
    LIPID_PEROXIDATION["LIPID PEROXIDATION<br/>Membrane Damage"]
    ALZHEIMER["Alzheimer's Disease<br/>Neurodegeneration"]
    ALS["Amyotrophic Lateral<br/>Sclerosis"]
    MS["Multiple Sclerosis<br/>Demyelination"]
    DEMENTIA["Dementia<br/>Cognitive Decline"]
    ISCHEMIA["Cerebral Ischemia<br/>Stroke"]
    NEURONAL_DEATH["NEURONAL DEATH<br/>Cell Loss"]
    GSH["Glutathione<br/>Antioxidant"]
    IRON_METABOLISM["Iron Metabolism<br/>Dysregulation"]

    SLC7A11 -->|"regulates"| GPX4
    GSH -->|"cofactor"| GPX4
    GPX4 -->|"inhibits"| FERROPTOSIS
    GPX4 -->|"maintains"| REDOX_HOMEOSTASIS
    GPX4 -->|"prevents"| LIPID_PEROXIDATION
    AUTOPHAGY -->|"degrades"| GPX4
    IRON_METABOLISM -->|"promotes"| FERROPTOSIS
    FERROPTOSIS -->|"causes"| NEURONAL_DEATH
    LIPID_PEROXIDATION -->|"triggers"| FERROPTOSIS
    NEURONAL_DEATH -->|"leads_to"| ALZHEIMER
    NEURONAL_DEATH -->|"leads_to"| ALS
    NEURONAL_DEATH -->|"leads_to"| MS
    NEURONAL_DEATH -->|"leads_to"| DEMENTIA
    ISCHEMIA -->|"activates"| FERROPTOSIS
    GPX4 -->|"therapeutic_target"| ALS
    GPX4 -->|"therapeutic_target"| MS

    style GPX4 fill:#006494
    style SLC7A11 fill:#4a1a6b
    style GSH fill:#1b5e20
    style REDOX_HOMEOSTASIS fill:#1b5e20
    style FERROPTOSIS fill:#ef5350
    style LIPID_PEROXIDATION fill:#ef5350
    style NEURONAL_DEATH fill:#ef5350
    style ALZHEIMER fill:#5d4400
    style ALS fill:#5d4400
    style MS fill:#5d4400
    style DEMENTIA fill:#5d4400
    style ISCHEMIA fill:#5d4400
    style AUTOPHAGY fill:#4a1a6b
    style IRON_METABOLISM fill:#4a1a6b

Gpx4 Gene Glutathione Peroxidase 4 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

GPX4 (Glutathione Peroxidase 4) encodes a unique glutathione peroxidase that reduces lipid hydroperoxides to their corresponding alcohols, making it the central enzyme preventing ferroptosis - an iron-dependent, lipid peroxidation-driven form of cell death. Unlike other GPX family members, GPX4 directly reduces complex lipid peroxides within cellular membranes.

Molecular Function

Enzymatic Activity

GPX4 catalyzes the reduction of lipid hydroperoxides using glutathione (GSH):

• Substrates: Phospholipid hydroperoxides (PLOOH), cholesterol hydroperoxides, lipid peroxides

• Co-substrate: Glutathione (two molecules per reaction)

• Products: Corresponding alcohols, oxidized glutathione (GSSG)

• Selenocysteine: Contains a selenocysteine at the active site, conferring high catalytic efficiency

Unique Substrate Specificity

What distinguishes GPX4 from other glutathione peroxidases:

1. Reduces lipid peroxides in membranes and lipoproteins

2. Works directly on phospholipid bilayers

3. Prevents ferroptotic cell death

4. Essential for survival of cells with high lipid content (neurons)

Expression Pattern

Brain Expression

GPX4 is expressed in various neural cell types:

• Neurons: High expression, especially in pyramidal neurons of cortex and hippocampus

• Astrocytes: Moderate expression, supports antioxidant defense

• Oligodendrocytes: Critical for myelin protection (high lipid content)

• Microglia: Expression in activated states

Regional Distribution

• Hippocampus: High expression in CA1-CA3 pyramidal neurons

• Cortex: Moderate to high expression in cortical layers

• Cerebellum: Purkinje cells show high expression

• Substantia Nigra: Dopaminergic neurons express GPX4

Disease Associations

Amyotrophic Lateral Sclerosis (ALS)

• GPX4 activity is reduced in ALS motor neurons

• ^{2*Ferroptosis: A regulated necrosis driven by lipid peroxidation*. Nature Reviews Drug DiscoveryFerroptosis: A regulated necrosis driven by lipid peroxidation · PMID 32877946Open reference}(/entities/ferroptosis) is implicated as a cell death mechanism

• Lipid peroxidation markers are elevated in ALS patients

• GPX4 overexpression protects motor neurons in models

• Selenoproteins are dysregulated in ALS

Parkinson’s Disease

• GPX4 expression is decreased in substantia nigra

• Lipid peroxidation is a hallmark of PD

• Iron accumulation in PD brains promotes ferroptosis

• Enhancing GPX4 may protect dopaminergic neurons

Alzheimer’s Disease

• Aβ induces lipid peroxidation in neurons

• GPX4 activity declines with age and in AD

• Ferroptosis may contribute to neuronal loss

• Therapeutic strategies aim to boost GPX4

Epilepsy

• GPX4 deficiency increases seizure susceptibility

• Ferroptosis may contribute to seizure-induced neuronal damage

Therapeutic Targeting

GPX4 Activators

Indirect Modulators

Genetic Variants

• Selenocysteine variants: Affect enzyme activity

• Polymorphisms: Associated with disease risk

• Knockout models: Embryonic lethal in mice (essential gene)

Research Directions

• Develop small molecule GPX4 activators

• Understand cell-type specific GPX4 regulation

• Explore gene therapy approaches

• Identify ferroptosis biomarkers

Key Publications

Background

The study of Gpx4 Gene Glutathione Peroxidase 4 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.

See Also

• Ferroptosis Pathway

• SLC7A11 Gene

• Oxidative Stress Pathway

• ALS Gene List

• Parkinson’s Disease Genes

• Alzheimer’s Disease Genes

External Links

• NCBI Gene: GPX4

• UniProt: P36969

• Ensembl: ENSG00000167468

• GeneCards: GPX4