OGG1 Protein

OGG1 Protein

Introduction

Ogg1 Protein is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.

<div class="infobox infobox-protein"> [@gbook2019]
<div class="infobox-header">OGG1 Protein</div> [@van2019]
<div class="infobox-content"> [@fukui2021] Gene: OGG1<br> [@wang2017] UniProt ID: O15527<br> [@kim2019] PDB ID: 2NOB, 1E3M, 1YQR<br> [@small2020] Molecular Weight: 39 kDa<br> [@wang2019] Subcellular Localization: Nucleus, Mitochondria<br> [@klungland2017] Protein Family: FPG/Nei family (DNA glycosylase)
</div>
</div>

Overview

OGG1 (8-Oxoguanine DNA Glycosylase) is a 39 kDa DNA repair enzyme that initiates the base excision repair (BER) pathway by removing 8-oxoguanine (8-oxoG) lesions from DNA. As the primary enzyme responsible for removing this mutagenic oxidative DNA damage, OGG1 is essential for preventing mutations and maintaining genomic integrity in [neurons](/entities/neurons), which are particularly vulnerable to oxidative stress due to high metabolic demand, catecholamine oxidation, and limited regenerative capacity.

Structure

OGG1 belongs to the FPG/Nei family of DNA glycosylases:

• N-terminal region: Contains mitochondrial targeting sequence (for mtOGG1 isoform)
• DNA-binding domain: Helix-hairpin-helix (HhH) motif for DNA recognition
• Catalytic domain: Contains the active site for 8-oxoG excision
• Iron-sulfur cluster: 4Fe-4S cluster required for structural stability

OGG1 Protein

Introduction

Ogg1 Protein is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.

<div class="infobox infobox-protein"> [@gbook2019]
<div class="infobox-header">OGG1 Protein</div> [@van2019]
<div class="infobox-content"> [@fukui2021] Gene: OGG1<br> [@wang2017] UniProt ID: O15527<br> [@kim2019] PDB ID: 2NOB, 1E3M, 1YQR<br> [@small2020] Molecular Weight: 39 kDa<br> [@wang2019] Subcellular Localization: Nucleus, Mitochondria<br> [@klungland2017] Protein Family: FPG/Nei family (DNA glycosylase)
</div>
</div>

Overview

OGG1 (8-Oxoguanine DNA Glycosylase) is a 39 kDa DNA repair enzyme that initiates the base excision repair (BER) pathway by removing 8-oxoguanine (8-oxoG) lesions from DNA. As the primary enzyme responsible for removing this mutagenic oxidative DNA damage, OGG1 is essential for preventing mutations and maintaining genomic integrity in [neurons](/entities/neurons), which are particularly vulnerable to oxidative stress due to high metabolic demand, catecholamine oxidation, and limited regenerative capacity.

Structure

OGG1 belongs to the FPG/Nei family of DNA glycosylases:

• N-terminal region: Contains mitochondrial targeting sequence (for mtOGG1 isoform)
• DNA-binding domain: Helix-hairpin-helix (HhH) motif for DNA recognition
• Catalytic domain: Contains the active site for 8-oxoG excision
• Iron-sulfur cluster: 4Fe-4S cluster required for structural stability

Normal Function

OGG1 functions in DNA repair:

• 8-oxoG Excision: Primary enzyme removing 8-oxoguanine from DNA
• AP Site Processing: Creates abasic site for subsequent repair by AP endonucleases
• Mutagenesis Prevention: Prevents G:C to T:A transversions during replication
• DNA Damage Signaling: 8-oxoG release can trigger stress response pathways
• Mitochondrial DNA Repair: mtOGG1 isoform repairs mitochondrial genome
• Base Excision Repair: Initiates BER pathway for oxidative DNA damage

Expression Pattern

OGG1 is ubiquitously expressed with highest levels in:

• Brain: [Hippocampus](/brain-regions/hippocampus), cerebral [cortex](/brain-regions/cortex), and substantia nigra
• Liver: High metabolic activity requiring DNA protection
• Kidney: Constant exposure to oxidative stress
• Testis: High cell division requiring genomic integrity

Role in Disease

Parkinson's Disease

• 8-oxoG accumulates in substantia nigra of PD patients[@nakabeppu2012]
• OGG1 polymorphisms increase PD risk[@gbook2019]
• Dopamine oxidation creates 8-oxoG in neurons[@van2019]
• Mitochondrial OGG1 critical for dopaminergic neuron survival[@fukui2021]
• OGG1 activity declines with age, correlating with PD onset

Alzheimer's Disease

• 8-oxoG accumulates in AD hippocampus and cortex[@wang2017]
• [Aβ](/proteins/amyloid-beta) induces oxidative DNA damage requiring OGG1[@kim2019]
• OGG1 expression upregulated but insufficient to compensate[@small2020]
• DNA repair capacity correlates with cognitive decline[@wang2019]

Huntington's Disease

• 8-oxoG accumulates in striatal neurons[@klungland2017]
• OGG1 activity impaired in HD[^10]
• Mitochondrial dysfunction increases oxidative damage
• DNA repair deficits contribute to neuronal death

Animal Models

• Ogg1 Knockout Mice: Show increased 8-oxoG accumulation in brain, age-related neurodegeneration, and increased tumor susceptibility[^11]
• Conditional Knockout: Neuron-specific Ogg1 deletion leads to progressive motor deficits
• Transgenic Models: OGG1 overexpression protects against MPTP-induced parkinsonism
• Drosophila: OGG1 homolog (ogg1) mutants show shortened lifespan and neurodegeneration

Therapeutic Targeting

| Approach | Mechanism | Status | Notes |
|----------|-----------|--------|-------|
| OGG1 activators | Enhance 8-oxoG repair | Preclinical | Small molecule screens ongoing |
| NAD+ precursors | Support BER pathway | Phase II | NR, NMN may boost OGG1 activity |
| Antioxidants | Reduce oxidative stress | Clinical | Indirect benefit |
| Mitochondrial OGG1 | Targeted delivery | Preclinical | Novel therapeutic approach |
| Gene therapy | Increase OGG1 expression | Preclinical | AAV-OGG1 in development |

Research Directions

Current research focuses on:

• Developing brain-penetrant OGG1 activators
• Understanding OGG1 regulation by post-translational modifications
• Role of OGG1 in epigenetics and DNA damage signaling
• Mitochondrial-targeted OGG1 for neuroprotection
• Biomarker potential of 8-oxoG in cerebrospinal fluid

Key Publications

See Also

• [OGG1 Gene](/proteins/ogg1-protein)
• [DNA Repair Pathways](/mechanisms/dna-repair-pathways)
• [Oxidative Stress in Neurodegeneration](/mechanisms/oxidative-stress-pathway)
• [Parkinson's Disease](/diseases/parkinsons-disease)
• [Alzheimer's Disease](/diseases/alzheimers-disease)
• [Huntington's Disease](/diseases/huntingtons)
• [Mitochondrial Dysfunction](/mechanisms/mitochondrial-dysfunction-pathway)
• [Base Excision Repair](/mechanisms/dna-repair-pathways)

External Links

• [UniProt: OGG1](https://www.uniprot.org/uniprot/O15527)
• [PDB: OGG1 Structure](https://www.rcsb.org/structure/2NOB)
• [NCBI Gene: OGG1](https://www.ncbi.nlm.nih.gov/gene/4967)
• [OMIM: OGG1](https://www.omim.org/entry/605932)

Background

The study of Ogg1 Protein 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.

Brain Atlas Resources

• [Allen Human Brain Atlas - OGG1 Expression](https://human.brain-map.org/microarray/search/show?search_term=OGG1)
• [Allen Cell Type Atlas - OGG1](https://celltypes.brain-map.org/)
• [Allen Mouse Brain Atlas - OGG1](https://mouse.brain-map.org/)
• [BrainSpan - OGG1 Developmental Expression](https://www.brainspan.org/)

References