Panel A shows fluorescence microscopy images and zoomed insets comparing Col1A1-mNeonGreen condensates with lysotracker-labeled lysosomal structures. Panel B shows fluorescence microscopy images and zoomed insets illustrating Col1A1-mNeonGreen condensates and Bip chaperone localization patterns. Panel C shows fluorescence microscopy images and enlarged insets comparing organized Col1A1 condensates and disorganized Col1A1 regions with Bip localization. Panel D shows fluorescence intensity profile graphs comparing Col1A1 and Bip fluorescence distributions across selected intracellular regions. The horizontal axes represent distance in micrometers, while the vertical axes represent Col1A1 and Bip fluorescence intensity values in arbitrary units. Panel E shows a scatter plot comparing Manders colocalization coefficients between Bip and Col1A1 under condensate and disorganized conditions. The vertical axis represents Bip to Col1A1 colocalization values, while the horizontal axis represents organizational categories.
PC1 in condensates is not targeted for degradation. (A) Fluorescence images of LX-2 cells stably expressing Col1A1-mNG (green) stained with LysoTracker Red (magenta) (top), and zoomed inset (bottom) showing that lysosomes are not in the vicinity of PC1 condensates. Images are stills corresponding to Video 5 (scale bar: 10 µm; inset: 2 µm). (B) Fluorescence images of fixed LX-2 cells stably expressing Col1A1-mNG (green) and stained using antibodies against the chaperone Bip (magenta) (top), and zoomed inset (bottom) showing Bip is excluded from PC1 condensates (scale bar: 10 µm; inset: 2 µm). (C) Fluorescence images of fixed LX-2 cells stably expressing Col1A1-mNG (green) and stained using antibodies against Bip (magenta) showing a cell with PC1 condensates (1) and another with disorganized PC1 (2) (top), and zoomed insets of regions corresponding to 1 and 2 (bottom) (scale bars: 10 µm; inset: 2 µm). (D) Fluorescence intensity profiles corresponding to the dashed white lines in zoomed insets 1 and 2 of D for Col1A1-mNG (green) and anti-Bip (magenta) in PC1 condensates and disorganized PC1 highlighting increased Bip accumulation in disorganized PC1 patches. (E) Manders’ colocalization coefficient M2 for Col1A1-mNG and anti-Bip in cells with either PC1 condensates or disorganized PC1. A total of 15 cells with PC1 condensates and seven cells with disorganized PC1 from two independent experiments were analyzed (****P < 0.0001).