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Updated: May 12, 2025
14:08
Study of Protein-protein Interactions in Autophagy Research
Published on: September 9, 2017
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TRIM22 functions as a scaffold protein for autophagy initiation
Hyungsun Park1, Hansol Heo2, Yeongseo Song1
1Program in Biomedical Science & Engineering, Inha University, Incheon, Republic of Korea.
Animal Cells and Systems
|May 8, 2025
Summary
Tripartite motif protein 22 (TRIM22) acts as a scaffold, promoting autophagy initiation by assembling key protein complexes. This expands its known role in autophagosome-lysosome fusion, revealing TRIM22
Area of Science:
- Cell Biology
- Molecular Biology
- Autophagy Regulation
Background:
- Tripartite motif (TRIM) family proteins are crucial regulators of autophagy.
- TRIM22 was known to mediate autophagosome-lysosome fusion.
- The role of TRIM22 in earlier autophagy stages, specifically initiation, was unexplored.
Purpose of the Study:
- To investigate the function of TRIM22 in autophagy initiation.
- To elucidate the molecular mechanisms underlying TRIM22's role in autophagy.
Main Methods:
- Overexpression of TRIM22 in cell lines.
- Analysis of autophagy markers (LC3-II) and autophagic flux.
- Co-immunoprecipitation and domain mapping to identify protein interactions.
- Assessment of TRIM22 variant function in cell lines and primary neurons.
Main Results:
- TRIM22 overexpression enhanced autophagic flux without affecting mTOR or AMPK.
- TRIM22 interacts with ULK1 and class III PI3K complex components via distinct domains.
- TRIM22 functions as a scaffold protein, recruiting ULK1 and PI3K complexes to autophagosome formation sites.
- The Alzheimer's disease-associated variant R321K retained autophagy initiation function.
Conclusions:
- TRIM22 plays a dual role in autophagy, regulating both initiation and fusion.
- TRIM22 acts as a scaffold protein to promote autophagy initiation by assembling key complexes.
- These findings reveal novel mechanisms of TRIM protein regulation across multiple autophagy stages.
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