Fig. 2: RAB10⁺ tubular membrane reservoirs are PM-associated.

a Representative images of WT Henle 407 cells transfected with GFP-RAB10 and stained for CellMask. XZ section was chosen to depict RAB10⁺ tubules’ colocalization with CellMask. Mander’s correlation coefficient (MCC) values for the relationship between CellMask (channel 1) and GFP-RAB10 (channel 2) were calculated to indicate colocalizations (M1 = 0.61 ± 0.12, M2 = 0.54 ± 0.12, and mean ± SD). b Line plot profile of the white arrow in the XZ section in (a). In this and the following panels, arb. units (arbitrary units) indicate the signal densities along the chosen white arrow. c Representative images of RAB10⁺ tubules in Henle 407 cells positive for indicated plasma membrane (PM) markers and identified as deep PM reservoirs. White arrows and boxes indicate RAB10⁺ deep PM invaginations. In this and the following panels, MCC values were calculated to indicate colocalizations between two channels (the left panel as channel 1 and the right panel as channel 2). For FM 4-64 (channel 1) and GFP-RAB10 (channel 2), M1 = 0.56 ± 0.11 and M2 = 0.52 ± 0.07. For PM-mCherry and GFP-RAB10, M1 = 0.58 ± 0.07 and M2 = 0.53 ± 0.08. For WGA and GFP-RAB10, M1 = 0.57 ± 0.07 and M2 = 0.53 ± 0.06. For 2PH-PLCδ-GFP and Td-RAB10, M1 = 0.59 ± 0.05 and M2 = 0.51 ± 0.10. d Line plot profiles of the white arrows in the insets in (c). e Quantifications of RAB10⁺ tubules in Henle 407 cells were positive for indicated PM markers and identified as deep PM reservoirs. n = 3 Independent experiments with 100 cells examined in each experiment. f Representative images of WT Henle 407 cells transfected with PM-mCherry and stained for endogenous RAB10. The inset (lower panel) was chosen to depict endogenous RAB10+ tubules’ colocalization with PM-mCherry. MCC values for PM-mCherry and endogenous RAB10 are M1 = 0.52 ± 0.08 and M2 = 0.51 ± 0.10. g Line plot profile of the white arrow in the inset in (f). Data shown are means ± SD. Scale bars, 10 μm. Source data are provided as a Source Data file.