TY - JOUR
T1 - LC3 and GATE-16 N Termini Mediate Membrane Fusion Processes Required for Autophagosome Biogenesis
AU - Weidberg, Hilla
AU - Shpilka, Tomer
AU - Shvets, Elena
AU - Abada, Adi
AU - Shimron, Frida
AU - Elazar, Zvulun
PY - 2011/4/19
Y1 - 2011/4/19
N2 - Autophagy is a unique membrane trafficking pathway describing the formation and targeting of double membrane autophagosomes to the vacuole/lysosome. The biogenesis of autophagosomes and their delivery to the vacuole/lysosome depend on multiple membrane fusion events. Using a cell-free system, we have investigated the ability of LC3 and GATE-16, two mammalian Atg8 orthologs, to mediate membrane fusion. We found that both proteins promote tethering and membrane fusion, mediated by the proteins' N-terminal α helices. We further show that short, 10 amino acid long synthetic peptides derived from the N terminus of LC3 or GATE-16 are sufficient to promote membrane fusion. Our data indicate that the fusion activity of LC3 is mediated by positively charged amino acids, whereas the activity of GATE-16 is mediated by hydrophobic interactions. Finally, we demonstrate that LC3 and GATE-16 N termini in general and specific residues needed for the fusion activity are essential for the proteins role in autophagosome biogenesis.
AB - Autophagy is a unique membrane trafficking pathway describing the formation and targeting of double membrane autophagosomes to the vacuole/lysosome. The biogenesis of autophagosomes and their delivery to the vacuole/lysosome depend on multiple membrane fusion events. Using a cell-free system, we have investigated the ability of LC3 and GATE-16, two mammalian Atg8 orthologs, to mediate membrane fusion. We found that both proteins promote tethering and membrane fusion, mediated by the proteins' N-terminal α helices. We further show that short, 10 amino acid long synthetic peptides derived from the N terminus of LC3 or GATE-16 are sufficient to promote membrane fusion. Our data indicate that the fusion activity of LC3 is mediated by positively charged amino acids, whereas the activity of GATE-16 is mediated by hydrophobic interactions. Finally, we demonstrate that LC3 and GATE-16 N termini in general and specific residues needed for the fusion activity are essential for the proteins role in autophagosome biogenesis.
UR - http://www.scopus.com/inward/record.url?scp=79954544250&partnerID=8YFLogxK
U2 - 10.1016/j.devcel.2011.02.006
DO - 10.1016/j.devcel.2011.02.006
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C2 - 21497758
AN - SCOPUS:79954544250
SN - 1534-5807
VL - 20
SP - 444
EP - 454
JO - Developmental Cell
JF - Developmental Cell
IS - 4
ER -