| Claim/Function | Evidence type | Key experimental details/quantitative results | Cellular location | Source (authors, year, journal, DOI URL) |
|---|---|---|---|---|
| SPBC660.08/mug167 is the bona fide **S. pombe Atg38** and a **PtdIns3K/PI3K complex I** subunit | AP-MS/co-purification, domain analysis | SPBC660.08 co-purified with Vps34, Vps15, Atg6, and **Atg14**, but not the complex II-specific subunit **Vps38**; protein architecture reported as N-terminal **MIT** domain plus C-terminal coiled-coil, matching Atg38 family assignment | Autophagy-specific PI3K complex at the PAS/phagophore | Yu et al., 2020, *Autophagy*, https://doi.org/10.1080/15548627.2020.1713644 (pqac-00000000, pqac-00000025) |
| Atg38 is an auxiliary/regulatory PI3K complex I subunit with conserved **MIT** and C-terminal homodimerization/coiled-coil regions | HDX-MS, X-ray crystallography, EM, SEC-MALS | Structural work showed Atg38 binds complex I through its **MIT** domain; the C-terminal region forms a homodimeric “mushroom-like” structure and supports PAS localization/complex association; yeast complex I engages **one Atg38 homodimer** | Base of PI3K complex I; PAS/autophagic puncta | Ohashi et al., 2016, *Autophagy*, https://doi.org/10.1080/15548627.2016.1226736 (pqac-00000015, pqac-00000016, pqac-00000019) |
| Atg38 directly binds **Atg8** through an **AIM** | Co-IP, GST pull-down, yeast two-hybrid, mutagenesis | AIM mapped to a conserved region around **aa 173-185**; **F178** and **V181** are critical; deleting **aa 176-181** or mutating **F178A/V181A** abolished or strongly weakened Atg8 binding; reciprocal **Atg8 P52A/R67A** mutations weakened binding | PAS/phagophore assembly site (Atg8-positive puncta) | Yu et al., 2020, *Autophagy*, https://doi.org/10.1080/15548627.2020.1713644 (pqac-00000002, pqac-00000004, pqac-00000027) |
| Atg38 localization to starvation-induced puncta depends on the autophagy machinery and supports recruitment to Atg8-positive structures | Fluorescence microscopy/colocalization | Atg38 formed starvation-induced puncta that colocalized with Atg8; **Atg14** was required for Atg38 puncta formation, consistent with complex I-dependent PAS targeting | PAS/phagophore | Yu et al., 2020, *Autophagy*, https://doi.org/10.1080/15548627.2020.1713644 (pqac-00000002, pqac-00000027) |
| **Atg38-Atg8 interaction** establishes a positive feedback loop that increases PAS accumulation of PI3K complex I and downstream Atg factors | Mutagenesis, fluorescence microscopy, FLIP | AIM-disrupting mutations did **not** alter upstream PAS factors (**Atg13, Atg9**) but reduced PAS accumulation of **Atg14** and downstream factors **Atg18b, Atg24b, Atg2, Atg5, Atg16, Atg8**; authors conclude the primary defect is reduced PAS accumulation of Atg38 itself | PAS/phagophore | Yu et al., 2020, *Autophagy*, https://doi.org/10.1080/15548627.2020.1713644 (pqac-00000000, pqac-00000003, pqac-00000006) |
| Loss of Atg38 or disruption of its Atg8 AIM reduces autophagic flux | CFP-Atg8 processing, Pho8Δ60, Tdh1-YFP processing | **atg38Δ** blocked starvation-induced **CFP-Atg8** processing and abolished starvation-induced increase in **Pho8Δ60** activity; **Atg38[AIM mut]** gave about **50% of WT** autophagic flux in the **Tdh1-YFP** processing assay | Vacuole-directed autophagic pathway; PAS-phagophore initiation step | Yu et al., 2020, *Autophagy*, https://doi.org/10.1080/15548627.2020.1713644 (pqac-00000002, pqac-00000004, pqac-00000027) |
| The Atg38-Atg8 interaction promotes normal **autophagosome size** | TEM, FLIP, mutagenesis | In an **fsc1Δ** background, average autophagosome diameter was **451 nm** with WT Atg38 versus **271 nm** with **Atg38[AIM mut]**; reported sample sizes included **n=45** and **n=30** in the size analyses | Autophagosome/phagophore | Yu et al., 2020, *Autophagy*, https://doi.org/10.1080/15548627.2020.1713644 (pqac-00000003, pqac-00000004) |
| AIM-dependent Atg8 binding is the key autophagy-promoting function tested in this study | Rescue by engineered interaction | Inserting an exogenous AIM (**3×EEEWEEL**) into **Atg38[AIM mut]** restored autophagy and autophagosome size to near-WT levels, showing that Atg8 binding per se is functionally important | PAS/phagophore | Yu et al., 2020, *Autophagy*, https://doi.org/10.1080/15548627.2020.1713644 (pqac-00000004) |
| In **S. pombe**, Atg38 is incorporated into PI3K complex I through **Vps34** | Pil1 co-tethering assay, ternary/quaternary interaction mapping | Pil1 assays showed **Atg38-Vps34** association; CFP-Vps34 could bridge **Vps15** and **Atg38**, indicating Vps34 links Atg38 to the rest of complex I; Vps34 **aa 1-250** mediated Vps15 interaction, whereas **aa 251-801** mediated Atg38 binding | PI3K complex I at the PAS | Yu et al., 2021, *Journal of Cell Science*, https://doi.org/10.1242/jcs.258774 (pqac-00000023, pqac-00000024, pqac-00000028, pqac-00000029) |
| A short conserved Atg38 region centered on **F157** is required for Vps34 binding | Mutagenesis, Pil1 co-tethering, quantitative colocalization | Deleting **aa 153-160** or mutating **F157A** largely blocked the **Atg38-Vps34** interaction; colocalization was quantified by **PCC (mean ± s.d., n=10 cells)** in the assay framework | PI3K complex I/PAS | Yu et al., 2021, *Journal of Cell Science*, https://doi.org/10.1242/jcs.258774 (pqac-00000023, pqac-00000024, pqac-00000026) |
| Disrupting the Atg38-Vps34 interface impairs autophagy, and forced linkage to Vps34 rescues function | Pho8Δ60 autophagy assay, fusion-rescue experiment | **Atg38F157A** diminished starvation-induced **Pho8Δ60** activation (assayed after **4 h nitrogen starvation**; normalized to +N = 1); **fusion of Vps34 to Atg38F157A** restored autophagic activity, supporting a direct incorporation role for the Vps34-Atg38 interaction | PAS/autophagy initiation pathway | Yu et al., 2021, *Journal of Cell Science*, https://doi.org/10.1242/jcs.258774 (pqac-00000023, pqac-00000024, pqac-00000026) |
| Atg38 has a relatively specific autophagy role rather than a broad vacuolar sorting defect | Phenotypic assays | **atg38Δ** cells showed autophagy defects but were reported as not temperature sensitive, with normal vacuole size and no Cpy1 mistargeting, supporting a relatively specific defect in autophagy initiation/efficiency | Autophagy pathway, not general vacuolar trafficking | Yu et al., 2020, *Autophagy*, https://doi.org/10.1080/15548627.2020.1713644 (pqac-00000002) |
| Current fission-yeast consensus places Atg38 as the fifth subunit of PI3K complex I and highlights a species-specific mechanism | Review synthesis from primary data | Review notes that in **S. pombe**, unlike budding yeast and mammals, Atg38 binds **directly to Vps34** and also carries an **AIM/LIR** that creates a positive-feedback loop to enhance PAS accumulation of PI3K complex I and downstream factors | PAS/phagophore, autophagy initiation machinery | Xu & Du, 2022, *Cells*, https://doi.org/10.3390/cells11071086; Ohashi, 2021, *Autophagy*, https://doi.org/10.1080/15548627.2021.1872240 (pqac-00000006, pqac-00000011, pqac-00000017, pqac-00000018) |


*Table: This table summarizes experimentally supported functional annotation for Schizosaccharomyces pombe Atg38/O94427, including complex I membership, interaction interfaces, localization, autophagy phenotypes, and rescue experiments. It highlights the main primary evidence and key quantitative findings useful for gene/protein annotation.*