ATG9B

ATG9B

Overview

Atg9B plays an important role in the study of neurodegenerative diseases. This page provides comprehensive information about this topic, including its mechanisms, significance in disease processes, and therapeutic implications.

<div class="infobox infobox-gene"> [@kishiitakura2014]
<div class="infobox-header">Gene Information</div> [@nishimura2020]
<div class="infobox-content"> [@stavoe2019] Symbol: ATG9B Full Name: Autophagy Related 9B (Autophagy-related protein 9B) Chromosomal Location: 7q36.1 NCBI Gene ID: [285525](https://www.ncbi.nlm.nih.gov/gene/285525) OMIM: [619384](https://www.omim.org/entry/619384) Ensembl ID: ENSG00000154997 UniProt ID: [Q7Z6Z8](https://www.uniprot.org/uniprot/Q7Z6Z8) Gene Family: ATG9 family Molecular Weight: ~77 kDa Aliases: EPT1, FLJ00134, SEO1
</div>
</div>

Introduction

ATG9B ([Autophagy](/entities/autophagy) Related 9B) is a gene encoding a key autophagy protein that plays essential roles in autophagosome biogenesis. ATG9B is a paralog of [ATG9A](/genes/atg9a) and shares significant functional homology with its counterpart. The gene is located on chromosome 7q36.1 and encodes a multipass transmembrane protein that is unique among autophagy-related proteins due to its integral membrane nature.

ATG9B is a critical component of the autophagy machinery, functioning as a scaffold protein that recruits other ATG proteins to the site of autophagosome formation. It is expressed in various tissues with particular abundance in the brain, liver, and endocrine tissues.

ATG9B

Overview

Atg9B plays an important role in the study of neurodegenerative diseases. This page provides comprehensive information about this topic, including its mechanisms, significance in disease processes, and therapeutic implications.

<div class="infobox infobox-gene"> [@kishiitakura2014]
<div class="infobox-header">Gene Information</div> [@nishimura2020]
<div class="infobox-content"> [@stavoe2019] Symbol: ATG9B Full Name: Autophagy Related 9B (Autophagy-related protein 9B) Chromosomal Location: 7q36.1 NCBI Gene ID: [285525](https://www.ncbi.nlm.nih.gov/gene/285525) OMIM: [619384](https://www.omim.org/entry/619384) Ensembl ID: ENSG00000154997 UniProt ID: [Q7Z6Z8](https://www.uniprot.org/uniprot/Q7Z6Z8) Gene Family: ATG9 family Molecular Weight: ~77 kDa Aliases: EPT1, FLJ00134, SEO1
</div>
</div>

Introduction

ATG9B ([Autophagy](/entities/autophagy) Related 9B) is a gene encoding a key autophagy protein that plays essential roles in autophagosome biogenesis. ATG9B is a paralog of [ATG9A](/genes/atg9a) and shares significant functional homology with its counterpart. The gene is located on chromosome 7q36.1 and encodes a multipass transmembrane protein that is unique among autophagy-related proteins due to its integral membrane nature.

ATG9B is a critical component of the autophagy machinery, functioning as a scaffold protein that recruits other ATG proteins to the site of autophagosome formation. It is expressed in various tissues with particular abundance in the brain, liver, and endocrine tissues.

Protein Structure

The ATG9B protein contains several distinctive features:

Transmembrane Domains

• Six transmembrane helices: Spanning the membrane multiple times
• N-terminal cytosolic domain: Contains linear sorting motifs
• C-terminal cytosolic domain: Functions in protein-protein interactions
• Lumenal loops: Form the core of the autophagosome

Functional Regions

• MIT domain: Microtubule-interacting and transport domain
• LC3-interacting region (LIR): Binds LC3/GABARAP family proteins
• Phosphorylation sites: Multiple serine/threonine residues for regulation

Biological Function

Autophagosome Formation

ATG9B is essential for autophagosome biogenesis through several mechanisms:

Cellular Processes

ATG9B participates in:

• Macroautophagy: Bulk degradation of cytoplasmic components
• Selective autophagy: Receptor-mediated degradation of specific cargoes
• ER-phagy: Endoplasmic reticulum turnover
• Mitophagy: Mitochondrial quality control

Tissue-Specific Functions

• Brain: Regulates neuronal autophagy, relevant to neurodegenerative diseases
• Liver: Controls hepatic autophagy and metabolism
• Pancreas: Modulates pancreatic β-cell function
• Immune cells: Regulates immune cell homeostasis

Expression Pattern

ATG9B shows tissue-specific expression:

• High expression: Brain ([cortex](/brain-regions/cortex), [hippocampus](/brain-regions/hippocampus), cerebellum), liver, pancreas
• Moderate expression: Heart, skeletal muscle, kidney
• Low expression: Lung, spleen, peripheral blood cells

Role in Neurodegenerative Diseases

Alzheimer's Disease (AD)

ATG9B dysfunction contributes to Alzheimer's disease pathogenesis:

Parkinson's Disease (PD)

In Parkinson's disease, ATG9B:

• Regulates mitophagy of damaged mitochondria
• Controls [α-synuclein](/proteins/alpha-synuclein) clearance
• Protects dopaminergic [neurons](/entities/neurons) from stress
• May be affected by [LRRK2](/entities/lrrk2) mutations

Amyotrophic Lateral Sclerosis (ALS)

ATG9B dysfunction in ALS:

• Impairs autophagy of protein aggregates
• Contributes to motor neuron degeneration
• May interact with [TDP-43](/mechanisms/tdp-43-proteinopathy) pathology

Huntington's Disease

In Huntington's disease:

• ATG9B regulates mutant [huntingtin](/proteins/huntingtin) clearance
• Autophagy defects contribute to disease progression
• Therapeutic targeting of autophagy is under investigation

Autophagy Machinery

ATG9B interacts with core autophagy proteins:

| Protein | Interaction | Function |
|---------|-------------|----------|
| [ATG2A/B](/genes/ATG2A) | Direct | Lipid transfer |
| [ATG18/WIPI2](/genes/wipi2) | Direct | Phagosome expansion |
| [LC3/GABARAP](/proteins/map1lc3a-protein) | Via LIR | Autophagosome formation |
| [ATG14](/genes/atg14) | Direct | Autophagosome nucleation |
| [ULK1](/genes/ulk1) | Indirect | Initiation complex |

See Also

• [ATG9A](/genes/atg9a) - Related autophagy protein
• [Autophagy in Neurodegeneration](/mechanisms/autophagy-lysosome-neurodegeneration)mechanisms/autophagy-lysosomal-pathway)
• [Alzheimer's Disease](/diseases/alzheimers-disease)
• [Parkinson's Disease](/diseases/parkinsons-disease)
• [Mitophagy](/mechanisms/mitophagy)
• [Genes Index](/genes)

External Links

• [NCBI Gene: ATG9B](https://www.ncbi.nlm.nih.gov/gene/285525) - Gene database
• [UniProt: ATG9B](https://www.uniprot.org/uniprot/Q7Z6Z8) - Protein database
• [PubMed: ATG9B](https://pubmed.ncbi.nlm.nih.gov/?term=ATG9B+autophagy+neurodegenerative) - Literature search

Overview

Atg9B plays an important role in the study of neurodegenerative diseases. This page provides comprehensive information about this topic, including its mechanisms, significance in disease processes, and therapeutic implications.

Background

The study of Atg9B 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.

References