ATG13 (Autophagy Related 13) is a key regulator of autophagy, a critical cellular process for degrading and recycling damaged organelles and protein aggregates. The ATG13 protein is part of the ULK1 complex (ULK1-ATG13-FIP200-ATG101), which initiates autophagosome formation in response to cellular energy status and nutrient availability. This protein plays a crucial role in neuronal health and is implicated in neurodegenerative diseases through its function in mitophagy and aggregate clearance. [@mizushima2009]
ATG13 (Autophagy Related 13) is a key regulator of autophagy, a critical cellular process for degrading and recycling damaged organelles and protein aggregates. The ATG13 protein is part of the ULK1 complex (ULK1-ATG13-FIP200-ATG101), which initiates autophagosome formation in response to cellular energy status and nutrient availability. This protein plays a crucial role in neuronal health and is implicated in neurodegenerative diseases through its function in mitophagy and aggregate clearance. [@mizushima2009]
<div class="infobox infobox-protein">
<table>
<tr><th colspan="2" style="background:#e8f4f8; text-align:center; font-size:1.1em;">Autophagy Related 13 Protein</th></tr>
<tr><td><strong>Protein Name</strong></td><td>ATG13</td></tr>
<tr><td><strong>Gene</strong></td><td><a href="/genes/atg13">ATG13</a></td></tr>
<tr><td><strong>UniProt ID</strong></td><td><a href="https://www.uniprot.org/uniprot/Q9UQL6">Q9UQL6</a></td></tr>
<tr><td><strong>PDB Structures</strong></td><td>5C6Z, 5ZVN, 5G0F</td></tr>
<tr><td><strong>Molecular Weight</strong></td><td>52 kDa</td></tr>
<tr><td><strong>Subcellular Localization</strong></td><td>Cytoplasm, Autophagosome</td></tr>
<tr><td><strong>Protein Family</strong></td><td>ATG13 family</td></tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/aging" style="color:#ef9a9a">Aging</a>, <a href="/wiki/als" style="color:#ef9a9a">Als</a>, <a href="/wiki/atherosclerosis" style="color:#ef9a9a">Atherosclerosis</a>, <a href="/wiki/cancer" style="color:#ef9a9a">Cancer</a>, <a href="/wiki/cardiovascular" style="color:#ef9a9a">Cardiovascular</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">108 edges</a></td>
</tr>
</table>
</div>
ATG13 is a 459 amino acid protein with an intrinsically disordered region that serves as a scaffold for the ULK1 complex. The protein contains an LC3-interacting region (LIR) that binds to LC3/GABARAP proteins during autophagy initiation. ATG13 also has a domain that interacts with FIP200 and ATG101 to form the stable ULK1 complex. [@ganley2011]
| Feature | Location | Function |
|---------|----------|----------|
| ULK1-binding domain | N-terminus | Binds and activates ULK1 kinase |
| FIP200-interacting region | Central | Scaffold for complex formation |
| ATG101-binding site | Central | Stabilizes ULK1 complex |
| LIR (LC3-interacting region) | aa 350-400 | Binds LC3/GABARAP proteins |
| Multiple phosphorylation sites | Throughout | Regulation by mTOR/AMPK |
ATG13 is a critical regulator of autophagy initiation. As part of the ULK1 complex (ULK1-ATG13-FIP200-ATG101), ATG13 senses cellular energy status via [AMPK](/mechanisms/ampk-signaling-pathway) and nutrient status via [mTOR](/mechanisms/mtor-signaling-pathway). When nutrients are scarce or energy is low, ATG13 promotes ULK1 kinase activation, leading to downstream autophagy induction. [@itakura2012]
Complex regulation:
In [neurons](/entities/neurons), ATG13-mediated autophagy is essential for: [@hong2017]
Dysregulation of ATG13 contributes to neurodegenerative diseases through impaired autophagy: [@nixon2014]
ATG13 plays a direct role in mitophagy through its interaction with the PINK1-PARKIN pathway: [@wang2019]
| Target | Agent | Mechanism | Status |
|--------|-------|-----------|--------|
| mTOR inhibitors | Rapamycin, Everolimus | Induce autophagy via ATG13/ULK1 | Approved |
| ULK1 activators | AZD8055, Torin1 | Activate autophagy initiation | Research |
| Autophagy inducers | Trehalose, Spermidine, Lithium | Multiple pathways | Preclinical |