Journal: iScience

Article Title: Centrosomal P4.1-associated protein is a novel regulator of ESCRT pathway function during endosome maturation

doi: 10.1016/j.isci.2026.114659

Figure Lengend Snippet: CPAP depletion disrupts Rab5-to-Rab7 conversion (A) HeLa cells expressing control or CPAP shRNA were treated with untagged EGF for 60 min, stained for Rab5 and Rab7, and imaged by Airyscan super-resolution microscopy. Left: maximum intensity-projection images of Z stacks; middle: single Z-plane of images; right: co-localization (yellow) was quantified by determining the percentages of Rab5-positive (green) puncta containing Rab7 (red) puncta in representative single Z-planes of each cell and quantified from multiple cells across at least three experiments. (B) HeLa cells expressing control or CPAP shRNA were transfected with GFP-Rab5 and mCherry-Rab7 constructs, treated with untagged EGF for 60 min, and imaged by Airyscan super-resolution microscopy. Left: maximum intensity-projection images of Z stacks; middle: single Z-plane of images; right: co-localization (yellow) was quantified by determining the percentages of GFP-Rab5-positive (green) puncta containing mCherry-Rab7 (red) puncta in representative single Z-planes of each cell and quantified from multiple cells across at least three experiments. The object-based co-localization macro tool FIJI was employed. (C) HeLa cells stably expressing control or CPAP-shRNA were transfected with control vector (GFP), GFP-Rab7 (WT; wild-type) or GFP-Rab7 (DN; dominant negative) vector constructs, treated with AF555-EGF ligand for 60 min, and stained for CD63 to mark MVBs/late endosomes, and imaged by confocal microscopy to determine AF555-EGF and CD63 co-localization. Left top row: GFP expression in control and Rab7 construct-expressing cells; left bottom rows: representative single Z-plane of images showing ligand-bound EGFR-CD63 co-localization; right: co-localization (yellow) was quantified by determining the percentages of EGF-positive (red) puncta containing CD63 (green) puncta in representative single Z-planes of each cell and quantified from multiple cells across at least three experiments. Zoomed images correspond to the dashed inset boxes of the indicated images. Scale bars: 10 μm. p values: ∗∗∗∗<0.0001 by unpaired nonparametric Mann-Whitney test.

Article Snippet: The vector constructs expressing GFP-Rab5, GFP-Rab11, and mCherry-Rab7, GFP-Rab7-WT and GFP-Rab7-DN were purchased from Addgene. siRNA against HRS, ALIX and TSG101 were purchased from Santa Cruz Biotech.

Techniques: Expressing, Control, shRNA, Staining, Super-Resolution Microscopy, Transfection, Construct, Stable Transfection, Plasmid Preparation, Dominant Negative Mutation, Confocal Microscopy, MANN-WHITNEY

Journal: iScience

Article Title: Centrosomal P4.1-associated protein is a novel regulator of ESCRT pathway function during endosome maturation

doi: 10.1016/j.isci.2026.114659

Figure Lengend Snippet: CPAP depletion disrupts Rab5-to-Rab7 conversion (A) HeLa cells expressing control or CPAP shRNA were treated with untagged EGF for 60 min, stained for Rab5 and Rab7, and imaged by Airyscan super-resolution microscopy. Left: maximum intensity-projection images of Z stacks; middle: single Z-plane of images; right: co-localization (yellow) was quantified by determining the percentages of Rab5-positive (green) puncta containing Rab7 (red) puncta in representative single Z-planes of each cell and quantified from multiple cells across at least three experiments. (B) HeLa cells expressing control or CPAP shRNA were transfected with GFP-Rab5 and mCherry-Rab7 constructs, treated with untagged EGF for 60 min, and imaged by Airyscan super-resolution microscopy. Left: maximum intensity-projection images of Z stacks; middle: single Z-plane of images; right: co-localization (yellow) was quantified by determining the percentages of GFP-Rab5-positive (green) puncta containing mCherry-Rab7 (red) puncta in representative single Z-planes of each cell and quantified from multiple cells across at least three experiments. The object-based co-localization macro tool FIJI was employed. (C) HeLa cells stably expressing control or CPAP-shRNA were transfected with control vector (GFP), GFP-Rab7 (WT; wild-type) or GFP-Rab7 (DN; dominant negative) vector constructs, treated with AF555-EGF ligand for 60 min, and stained for CD63 to mark MVBs/late endosomes, and imaged by confocal microscopy to determine AF555-EGF and CD63 co-localization. Left top row: GFP expression in control and Rab7 construct-expressing cells; left bottom rows: representative single Z-plane of images showing ligand-bound EGFR-CD63 co-localization; right: co-localization (yellow) was quantified by determining the percentages of EGF-positive (red) puncta containing CD63 (green) puncta in representative single Z-planes of each cell and quantified from multiple cells across at least three experiments. Zoomed images correspond to the dashed inset boxes of the indicated images. Scale bars: 10 μm. p values: ∗∗∗∗<0.0001 by unpaired nonparametric Mann-Whitney test.

Article Snippet: GFP-Rab7 plasmid , Addgene , 61803.

Techniques: Expressing, Control, shRNA, Staining, Super-Resolution Microscopy, Transfection, Construct, Stable Transfection, Plasmid Preparation, Dominant Negative Mutation, Confocal Microscopy, MANN-WHITNEY

Journal: iScience

Article Title: Centrosomal P4.1-associated protein is a novel regulator of ESCRT pathway function during endosome maturation

doi: 10.1016/j.isci.2026.114659

Figure Lengend Snippet: CPAP depletion disrupts Rab5-to-Rab7 conversion (A) HeLa cells expressing control or CPAP shRNA were treated with untagged EGF for 60 min, stained for Rab5 and Rab7, and imaged by Airyscan super-resolution microscopy. Left: maximum intensity-projection images of Z stacks; middle: single Z-plane of images; right: co-localization (yellow) was quantified by determining the percentages of Rab5-positive (green) puncta containing Rab7 (red) puncta in representative single Z-planes of each cell and quantified from multiple cells across at least three experiments. (B) HeLa cells expressing control or CPAP shRNA were transfected with GFP-Rab5 and mCherry-Rab7 constructs, treated with untagged EGF for 60 min, and imaged by Airyscan super-resolution microscopy. Left: maximum intensity-projection images of Z stacks; middle: single Z-plane of images; right: co-localization (yellow) was quantified by determining the percentages of GFP-Rab5-positive (green) puncta containing mCherry-Rab7 (red) puncta in representative single Z-planes of each cell and quantified from multiple cells across at least three experiments. The object-based co-localization macro tool FIJI was employed. (C) HeLa cells stably expressing control or CPAP-shRNA were transfected with control vector (GFP), GFP-Rab7 (WT; wild-type) or GFP-Rab7 (DN; dominant negative) vector constructs, treated with AF555-EGF ligand for 60 min, and stained for CD63 to mark MVBs/late endosomes, and imaged by confocal microscopy to determine AF555-EGF and CD63 co-localization. Left top row: GFP expression in control and Rab7 construct-expressing cells; left bottom rows: representative single Z-plane of images showing ligand-bound EGFR-CD63 co-localization; right: co-localization (yellow) was quantified by determining the percentages of EGF-positive (red) puncta containing CD63 (green) puncta in representative single Z-planes of each cell and quantified from multiple cells across at least three experiments. Zoomed images correspond to the dashed inset boxes of the indicated images. Scale bars: 10 μm. p values: ∗∗∗∗<0.0001 by unpaired nonparametric Mann-Whitney test.

Article Snippet: GFP-Rab7 DN plasmid , Addgene , 12660.

Techniques: Expressing, Control, shRNA, Staining, Super-Resolution Microscopy, Transfection, Construct, Stable Transfection, Plasmid Preparation, Dominant Negative Mutation, Confocal Microscopy, MANN-WHITNEY

Journal: The EMBO Journal

Article Title: BLTP3A is associated with membranes of the late endocytic pathway and is an effector of CASM

doi: 10.1038/s44318-025-00543-9

Figure Lengend Snippet: ( A ) Fluorescence images of RPE-1 cells expressing exogenous BLTP3A-mRFP (shown in inverted grays) and (not shown) GFP-tagged wild-type Rab7 (left) or dominant negative (DN) Rab7 (T22N) (right). Scale bar, 5 μm. ( B ) CLEM of a BLTP3A-mRFP positive cluster in an RPE-1 cell expressing GFP-tagged dominant negative Rab7. Left: fluorescence image of BLTP3A-mRFP (magenta). Scale bar, 1 μm. Right: EM micrograph of the field shown at left revealing that the BLTP3A-mRFP fluorescence reflects clusters of small vesicles. Scale bar, 500 nm. ( C ) BLTP3 chimeras design. Left: Surface representation of the predicted RBG core of BLTP3A. Red and blue indicate positive and negative charges, respectively, and gray indicates hydrophobic surfaces. Right: Surface representation (top) and ribbon representation (bottom) of the “untwisted” protein showing individual RBG motifs. Bottom: Cartoon of chimeras consisting of BLTP3A (dark orange) and BLTP3B (light orange) RBG motifs. ( D ) High-magnification live fluorescence images of RPE-1 cells expressing the indicated BLTP3-mRFP constructs (magenta) and LAMP1-GFP (green). Individual channels are shown as inverted grays. Scale bar, 1 μm. ( E ) Ribbon representation of the AlphaFold prediction of a.a. 1–336 of BLTP3A. Blue indicates loops connecting adjoining RBG motifs, and gray indicates the first beta-strand of the third RBG motif. ( F ) Fluorescence images (inverted grays) of RPE-1 cells expressing BLTP3A-1-336-mRFP and either (not shown) GFP-Rab7 (left), or GFP-Rab7 T22N (right). Scale bar, 5 μm. A zoom of an area of the cell at left (dotted square) expressing BLTP3A-1-336-mRFP (magenta) is also shown, along with the Rab7 fluorescence (green), demonstrating the localization of BLTP3A-1-336-mRFP around the entire profile of lysosomes. Individual channels are shown as inverted grays. Scale bar, 2 μm. ( G ) Cartoon depicting the proposed association of BLTP3A vesicle clusters with the surface of lysosomes and the dependence of this association on Rab7.

Article Snippet: GFP-Rab7 T22N , Addgene , RRID:Addgene_28048.

Techniques: Fluorescence, Expressing, Dominant Negative Mutation, Construct