Abstract
During autophagy, the transmembrane protein Atg27 facilitates transport of the major autophagy membrane protein Atg9 to the preautophagosomal structure (PAS). To better understand the function of Atg27 and its relationship with Atg9, Atg27 trafficking and localization were examined. Atg27 localized to endosomes and the vacuolar membrane, in addition to previously described PAS, Golgi and Atg9-positive structures. Atg27 vacuolar membrane localization was dependent on the adaptor AP-3, which mediates direct transport from the trans-Golgi to the vacuole. The four C-terminal amino acids (YSAV) of Atg27 comprise a tyrosine sorting motif. Mutation of the YSAV abrogated Atg27 transport to the vacuolar membrane and affected its distribution in TGN/endosomal compartments, while PAS localization was normal. Also, in atg27(ΔYSAV) or AP-3 mutants, accumulation of Atg9 in the vacuolar lumen was observed upon autophagy induction. Nevertheless, PAS localization of Atg9 was normal in atg27(ΔYSAV) cells. The vacuole lumen localization of Atg9 was dependent on transport through the multivesicular body, as Atg9 accumulated in the class E compartment and vacuole membrane in atg27(ΔYSAV) vps4Δ but not in ATG27 vps4Δ cells. We suggest that Atg27 has an additional role to retain Atg9 in endosomal reservoirs that can be mobilized during autophagy. The transmembrane protein Atg27 facilitates transport of the major autophagy membrane protein, Atg9, to the preautophagosomal structure (PAS). This new study demonstrates that Atg27 has a tyrosine-sorting motif in its cytoplasmic tail that mediates its localization to the vacuole membrane by the AP-3 adaptor pathway. Moreover, this motif is also important for preventing Atg9 delivery to the vacuole lumen via the MVB pathway, suggesting that Atg27 retains Atg9 in endosomal reservoirs for mobilization during autophagy.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 365-378 |
| Number of pages | 14 |
| Journal | Traffic |
| Volume | 16 |
| Issue number | 4 |
| DOIs | |
| State | Published - Apr 1 2015 |
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Keywords
- AP-3
- Atg27
- Atg9
- Autophagy
- Cytoplasm to vacuole transport
- Endosome
- Preautophagosomal structure
- Trans-Golgi network
- Tyrosine sorting motif
- Vacuole
ASJC Scopus subject areas
- Biochemistry
- Cell Biology
- Structural Biology
- Molecular Biology
- Genetics
Cite this
Atg27 tyrosine sorting motif is important for its trafficking and Atg9 localization. / Segarra, Verónica A.; Boettner, Douglas R.; Lemmon, Sandra.
In: Traffic, Vol. 16, No. 4, 01.04.2015, p. 365-378.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Atg27 tyrosine sorting motif is important for its trafficking and Atg9 localization
AU - Segarra, Verónica A.
AU - Boettner, Douglas R.
AU - Lemmon, Sandra
PY - 2015/4/1
Y1 - 2015/4/1
N2 - During autophagy, the transmembrane protein Atg27 facilitates transport of the major autophagy membrane protein Atg9 to the preautophagosomal structure (PAS). To better understand the function of Atg27 and its relationship with Atg9, Atg27 trafficking and localization were examined. Atg27 localized to endosomes and the vacuolar membrane, in addition to previously described PAS, Golgi and Atg9-positive structures. Atg27 vacuolar membrane localization was dependent on the adaptor AP-3, which mediates direct transport from the trans-Golgi to the vacuole. The four C-terminal amino acids (YSAV) of Atg27 comprise a tyrosine sorting motif. Mutation of the YSAV abrogated Atg27 transport to the vacuolar membrane and affected its distribution in TGN/endosomal compartments, while PAS localization was normal. Also, in atg27(ΔYSAV) or AP-3 mutants, accumulation of Atg9 in the vacuolar lumen was observed upon autophagy induction. Nevertheless, PAS localization of Atg9 was normal in atg27(ΔYSAV) cells. The vacuole lumen localization of Atg9 was dependent on transport through the multivesicular body, as Atg9 accumulated in the class E compartment and vacuole membrane in atg27(ΔYSAV) vps4Δ but not in ATG27 vps4Δ cells. We suggest that Atg27 has an additional role to retain Atg9 in endosomal reservoirs that can be mobilized during autophagy. The transmembrane protein Atg27 facilitates transport of the major autophagy membrane protein, Atg9, to the preautophagosomal structure (PAS). This new study demonstrates that Atg27 has a tyrosine-sorting motif in its cytoplasmic tail that mediates its localization to the vacuole membrane by the AP-3 adaptor pathway. Moreover, this motif is also important for preventing Atg9 delivery to the vacuole lumen via the MVB pathway, suggesting that Atg27 retains Atg9 in endosomal reservoirs for mobilization during autophagy.
AB - During autophagy, the transmembrane protein Atg27 facilitates transport of the major autophagy membrane protein Atg9 to the preautophagosomal structure (PAS). To better understand the function of Atg27 and its relationship with Atg9, Atg27 trafficking and localization were examined. Atg27 localized to endosomes and the vacuolar membrane, in addition to previously described PAS, Golgi and Atg9-positive structures. Atg27 vacuolar membrane localization was dependent on the adaptor AP-3, which mediates direct transport from the trans-Golgi to the vacuole. The four C-terminal amino acids (YSAV) of Atg27 comprise a tyrosine sorting motif. Mutation of the YSAV abrogated Atg27 transport to the vacuolar membrane and affected its distribution in TGN/endosomal compartments, while PAS localization was normal. Also, in atg27(ΔYSAV) or AP-3 mutants, accumulation of Atg9 in the vacuolar lumen was observed upon autophagy induction. Nevertheless, PAS localization of Atg9 was normal in atg27(ΔYSAV) cells. The vacuole lumen localization of Atg9 was dependent on transport through the multivesicular body, as Atg9 accumulated in the class E compartment and vacuole membrane in atg27(ΔYSAV) vps4Δ but not in ATG27 vps4Δ cells. We suggest that Atg27 has an additional role to retain Atg9 in endosomal reservoirs that can be mobilized during autophagy. The transmembrane protein Atg27 facilitates transport of the major autophagy membrane protein, Atg9, to the preautophagosomal structure (PAS). This new study demonstrates that Atg27 has a tyrosine-sorting motif in its cytoplasmic tail that mediates its localization to the vacuole membrane by the AP-3 adaptor pathway. Moreover, this motif is also important for preventing Atg9 delivery to the vacuole lumen via the MVB pathway, suggesting that Atg27 retains Atg9 in endosomal reservoirs for mobilization during autophagy.
KW - AP-3
KW - Atg27
KW - Atg9
KW - Autophagy
KW - Cytoplasm to vacuole transport
KW - Endosome
KW - Preautophagosomal structure
KW - Trans-Golgi network
KW - Tyrosine sorting motif
KW - Vacuole
UR - http://www.scopus.com/inward/record.url?scp=84926076454&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84926076454&partnerID=8YFLogxK
U2 - 10.1111/tra.12253
DO - 10.1111/tra.12253
M3 - Article
C2 - 25557545
AN - SCOPUS:84926076454
VL - 16
SP - 365
EP - 378
JO - Traffic
JF - Traffic
SN - 1398-9219
IS - 4
ER -