Guanylate-Binding Protein 1 Regulates Infection-Induced Autophagy through TBK1 Phosphorylation

Figure 1

GBP1 localization around the autophagosome depending on guanine nucleotide recycling and lipidation. (a) Confocal micrographs of the GBP family around an autophagosome in GAS-infected cells. HeLa cells expressing the indicated EmGFP-GBPs (green) and mCherry-LC3 (red) were infected with GAS for 4 h. Cellular and bacterial DNA was stained with DAPI (cyan). All images are representative of three independent experiments. Insets: enlargements of the indicated areas. Scale bar: 10 μm. (b) Quantification of cells containing the GBP-positive autophagosome among GAS-infected cells; cells were manually counted by observing immunofluorescence using confocal microscopy. Data are presented as the from three independent experiments (100 infected cells were examined in each experiment). Of the seven GBP homologs, only data of autophagosome-localized GBPs are shown. (c) Confocal micrograph of GBP1 mutants and the autophagosome in GAS-infected cells. HeLa cells cotransfected with EmGFP-GBP1 mutants and mCherry-LC3 were infected with GAS for 4 h. Cellular and bacterial DNA was stained with DAPI. All images are representative of three independent experiments. Insets: enlargements of indicated areas. Scale bar: 10 μm. (d) Quantification of cells containing the GBP1 mutant-positive autophagosome in GAS-infected cells. Cells were manually counted by observing immunofluorescence using confocal microscopy. Data are presented as the from three independent experiments (50 infected cells were examined in each experiment). Asterisks indicate statistically significant differences () as determined by two-tailed Student’s -test. (e) Quantification of cells containing GBP1-positive GAS in HeLa WT and ATG5-knockout cells [57]. Cells were manually counted by observing immunofluorescence using confocal microscopy. Data are presented as the from three independent experiments (50 infected cells were examined in each experiment).

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