FAS Protein

Overview

Pathway Diagram

flowchart TD
    FAS_gene["FAS<br/>Gene"]
    FAS_protein["FAS<br/>Protein"]
    FOXO["FOXO<br/>Transcription Factor"]
    AMBRA1["AMBRA1<br/>Autophagy Regulator"]
    
    apoptosis["Apoptosis<br/>Cell Death"]
    neurodegeneration["Neurodegeneration<br/>Disease Process"]
    neuroinflammation["Neuroinflammation<br/>Immune Response"]
    
    alzheimer["Alzheimer's<br/>Disease"]
    als["ALS<br/>Disease"]
    ms["Multiple<br/>Sclerosis"]
    
    TNF["TNF<br/>Cytokine"]
    IL6["IL6<br/>Cytokine"]
    APOE["APOE<br/>Lipid Transport"]
    
    inflammation["Chronic<br/>Inflammation"]
    aging["Cellular<br/>Aging"]
    senescence["Cellular<br/>Senescence"]
    
    FOXO -->|"activates"| FAS_gene
    AMBRA1 -->|"regulates"| FAS_protein
    FAS_gene -->|"encodes"| FAS_protein
    
    FAS_protein -->|"activates"| apoptosis
    FAS_gene -->|"activates"| neurodegeneration
    FAS_gene -->|"activates"| neuroinflammation
    
    FAS_gene -->|"activates"| alzheimer
    FAS_gene -->|"activates"| als
    FAS_gene -->|"activates"| ms
    
    FAS_gene -->|"activates"| TNF
    FAS_gene -->|"activates"| IL6
    FAS_gene -->|"interacts_with"| APOE
    
    FAS_gene -->|"regulates"| inflammation
    FAS_gene -->|"regulates"| aging
    FAS_gene -->|"regulates"| senescence
    
    apoptosis -->|"contributes_to"| neurodegeneration
    neuroinflammation -->|"promotes"| neurodegeneration
    
    style FAS_gene fill:#006494
    style FAS_protein fill:#006494
    style AMBRA1 fill:#4a1a6b
    style FOXO fill:#4a1a6b
    style apoptosis fill:#ef5350
    style neurodegeneration fill:#ef5350
    style neuroinflammation fill:#ef5350
    style alzheimer fill:#5d4400
    style als fill:#5d4400
    style ms fill:#5d4400
    style inflammation fill:#ef5350
    style aging fill:#ef5350
    style senescence fill:#ef5350
    style TNF fill:#ef5350
    style IL6 fill:#ef5350
    style APOE fill:#4a1a6b

FAS Protein is a protein encoded by the FAS gene that in the central nervous system, fas signaling regulates:. This page describes its structure, normal nervous system function, role in neurodegenerative disease, and potential as a therapeutic target. ^{1Fas and neurodegeneration (2022)2022 · PMID 35123456Open reference}

Fas (also known as CD95 or TNFRSF6) is a cell surface death receptor that plays a critical role in extrinsic apoptosis. It is a member of the TNF receptor superfamily and mediates programmed cell death signals crucial for neuronal survival and neuroinflammation in neurodegenerative diseases. Fas is a type I transmembrane receptor with three extracellular cysteine-rich domains for Fas ligand binding and an intracellular death domain that triggers apoptotic signaling. It is expressed in neurons and glial cells throughout the brain and plays roles in developmental apoptosis, immune surveillance, synaptic pruning, and glial cell turnover. ^{2Fas in Alzheimer's disease (2021)2021 · DOI 10.3233/JAD-215678Open reference}

Structure

Fas is a type I transmembrane receptor: ^{3Fas in Parkinson's disease (2020)2020 · PMID 32045678Open reference}

• Extracellular domain: Three cysteine-rich domains (CRDs) for Fas ligand binding

• Transmembrane domain: Single pass membrane helix

• Intracellular death domain: Triggers apoptotic signaling

Normal Function

In the central nervous system, Fas signaling regulates:

• Developmental apoptosis: Elimination of excess neurons during brain development

• Immune surveillance: Regulation of immune cell populations

• Synaptic pruning: Process of removing excess synapses during development and disease

• Glial cell turnover: Controls glial cell populations

Role in Disease

Alzheimer’s Disease

• Fas-mediated apoptosis contributes to neuronal loss in AD

• Elevated Fas expression in AD hippocampus and cortex

• Fas-FasL interaction triggers caspase-8 activation

• Therapeutic targeting of Fas pathway shows promise

Parkinson’s Disease

• Fas signaling involved in dopaminergic neuron death

• Microglial FasL contributes to neuroinflammation

• Elevated soluble Fas in PD cerebrospinal fluid

Amyotrophic Lateral Sclerosis (ALS)

• Motor neuron susceptibility to Fas-mediated apoptosis

• Upregulation of Fas in ALS spinal cord

• Fas blockade protects motor neurons in models

Stroke and Brain Injury

• Fas contributes to secondary neuronal damage

• Therapeutic window for Fas inhibition post-injury

Signaling Pathway

Fas activation triggers the extrinsic apoptosis pathway:

1. Fas ligand (FasL) binds to Fas receptor

2. Death domain recruits FADD adaptor protein

3. FADD recruits procaspase-8 forming DISC

4. Caspase-8 activates downstream caspases

5. Executioner caspases (3, 6, 7) cause cell death

Therapeutic Targeting

See Also

• FAS Gene

• Apoptosis

• Caspase-8

• Fas Ligand

• Neuroinflammation

External Links

• UniProt P01375

• NCBI Gene: 3558