FIGURE 5.

SIK2 is essential for autophagosome processing. A, HEK293T cells were co-expressed mCherry-GFP-LC3 with siRNA targeting SIK1 or SIK2. After treatment with or without 0.2 μm bafilomycin A₁ (BFA) for 16 h, cells were fixed and analyzed by immunofluorescence and confocal microscopy (scale bar, 10 μm). B, electron microscopy images of SIK2 knockdown cells. HEK293T cells expressing control (shLuc) or SIK2-targeting (shSIK2) shRNA were subjected to transmission electron microscopy analysis. Control cells were also treated with (shLuc + BFA) or without (shLuc) 0.2 μm bafilomycin A₁ for 16 h. Bottom figures represent enlarged images of the boxed regions in the top figures. Arrow, autophagosome; M, mitochondria; N, nucleus. Scale bar, 1 μm.