pcmv mcherry rab5  (Addgene inc)

Journal: bioRxiv

Article Title: Branched actin constrains endosomal cargo to control sorting and fission

doi: 10.64898/2026.03.10.710749

Figure Lengend Snippet: Branched actin inhibition, but not formin inhibition, decreases actin at RAB5 QL endosomes. (A-P) . HeLa cells were transfected with mCherry-RAB5 Q79L and were either ( A-D ) untreated or treated with ( E-H ) 25 µM SMIFH2, ( I-L ) 300 µM CK-689, or ( M-P ) 300 µM CK-666 for 20 min. Cells were fixed and co-stained with cortactin and phalloidin to visualize the actin network. (Q) . Quantification of ( A-P ). RAB5 Q79L endosomes that colocalized with phalloidin or cortactin were counted as a percentage of total RAB5 Q79L endosomes. Quantification represents 15 images from three independent experiments. A two-tailed Mann-Whitney nonparametric test was used to determine significance between treatment groups. Data comparisons without error bars are not significant ( p > 0.05).

Article Snippet: The mCherry-RAB5 Q79L (35138, Addgene) plasmid was used to generate enlarged endosomes.

Techniques: Inhibition, Transfection, Staining, Two Tailed Test, MANN-WHITNEY

Journal: bioRxiv

Article Title: Branched actin constrains endosomal cargo to control sorting and fission

doi: 10.64898/2026.03.10.710749

Figure Lengend Snippet: Transferrin is bounded by cortactin at endosomes. (A-L) . HeLa cells were transfected with mCherry-RAB5 Q79L and were incubated with ( A-C ) no inhibitor, ( D-F ) 25 µM SMIFH2, ( G-I ) 300 µM CK-689, or ( J-L ) 300 µM CK-666 for 4 min. Following the pre-treatment, cells were incubated with Tf-488 (and their respective inhibitor) for 6 min of uptake. (M-P) . Representative fluorescence intensity profiles of endosomes from ( M ) untreated, ( N ) SMIFH2-treated cells, ( O ) CK-689-treated cells, or ( P ) CK-666-treated cells. The intensity profile of Tf is in green, and the intensity profile of cortactin is in magenta. Tf vertices above 130% that occur within 20 degrees of a cortactin value above 130% are represented with a red circle; these peaks are “bounded”. Tf vertices above 130% that are not within 20 degrees of a cortactin value above 130% are represented with a grey circle and are “not bounded”. (Q). The percentage of “bounded” Tf peaks was quantified from fluorescence intensity profiles (as represented in ( M-P )). Quantification is from three independent experiments, and from 37 endosomes for the untreated group, 43 endosomes for SMIFH2-treated, 38 endosomes for CK-689-treated, and 37 endosomes from the CK-666-treated group. Statistical significance was determined using a two-tailed unpaired t -test (ns: p > 0.05). (R, S) . Representative models for the quantification and results of the experiment. A circle was drawn around the endosome membrane (red) that intersects with the regions of Tf (green) and cortactin (magenta), and fluorescence intensity at each degree around the circle was measured. ( R ) Untreated cells have Tf in confined regions on the endosome and are adjacent to regions of cortactin ∼60% of the time. ( S ) CK-666-treated cells have regions of Tf that are broader and “not bounded” by cortactin.

Article Snippet: The mCherry-RAB5 Q79L (35138, Addgene) plasmid was used to generate enlarged endosomes.

Techniques: Transfection, Incubation, Fluorescence, Two Tailed Test, Membrane

Journal: bioRxiv

Article Title: Branched actin constrains endosomal cargo to control sorting and fission

doi: 10.64898/2026.03.10.710749

Figure Lengend Snippet: Tf occupies less discrete regions on the endosome when branched actin is inhibited. (A-L) . HeLa cells were transfected with mCherry-RAB5 Q79L and were incubated with ( A-C ) no inhibitor, ( D-F ) 25 µM SMIFH2, ( G-I ) 300 µM CK-689, or ( J-L ) 300 µM CK-666 for 4 min. Following the pre-treatment, cells were incubated with Tf-488 (and their respective inhibitor) for 6 min of uptake. Untreated, SMIFH2-treated, and CK-689-treated cells show Tf localized to discrete regions on the endosome (yellow arrows). CK-666-treated cells have broader regions of Tf on the endosome (blue arrows). (M). Model for quantification. A circle (blue) was drawn around the endosome membrane (red) that intersects with the regions of Tf, and the fluorescence intensity at each degree around the circle was measured. (N-Q) . Representative fluorescence intensity profiles of Tf on the endosome from ( N ) untreated, ( O ) SMIFH2-treated, ( P ) CK-689-treated, and ( Q ) CK-666-treated cells. The profiles depicted are from the endosomes indicated with a magenta-colored star ( A-L ). (R). Tf-containing regions from the fluorescence intensity profiles ( N-Q ) were identified, and the fluorescence values ± 20 degrees from the maximum were normalized. These normalized profiles of Tf-containing regions are Tf “peaks”. The graph shows the average profile of 72 Tf peaks from 37 endosomes for the control group, 70 peaks from 43 endosomes from SMIFH2-treated cells, 73 peaks from 38 endosomes from CK-689-treated cells, and 70 peaks from 37 endosomes from CK-666-treated cells. Data are from three independent experiments. The average profile of Tf peaks in the CK-666-treated cells is broader (less discrete) than the other treatment groups. See table in Figure EV3 for statistical information.

Article Snippet: The mCherry-RAB5 Q79L (35138, Addgene) plasmid was used to generate enlarged endosomes.

Techniques: Transfection, Incubation, Membrane, Fluorescence, Control

Journal: bioRxiv

Article Title: Branched actin constrains endosomal cargo to control sorting and fission

doi: 10.64898/2026.03.10.710749

Figure Lengend Snippet: EGF segregation on the endosome is affected by branched actin inhibition. (A-L) . HeLa cells were transfected with mCherry-RAB5 Q79L and were incubated with ( A-C ) no inhibitor, ( D-F ) SMIFH2, ( G-I ) CK-689, or ( J-L ) CK-666 for 4 min. Following the pre-treatment, cells were incubated with EGF-488 (and the respective inhibitor) for 17 min of uptake. Untreated, SMIFH2-treated, and CK-689-treated cells show EGF localized to discrete regions on the endosome (yellow arrows). CK-666-treated cells have broader regions of EGF on the endosome (blue arrows). (M-P) . Representative fluorescence intensity profiles of EGF on the endosome from the ( M ) untreated, ( N ) SMIFH2-treated, ( O ) CK-689-treated, and ( P ) CK-666 treated cells. The profiles depicted are from the endosomes indicated with a magenta star in ( A-L ). (Q) . EGF-containing regions from the fluorescence intensity profiles ( M-P ) were identified, and the fluorescence values ± 20 degrees from the maximum were normalized. These normalized profiles of EGF-containing regions are EGF “peaks”. The graph shows the average profile of 84 EGF peaks from 47 endosomes that were analyzed for the control group, 86 peaks from 51 endosomes from SMIFH2-treated cells, 72 peaks from 39 endosomes from CK-689-treated cells, and 86 peaks from 49 endosomes from CK-666-treated cells. Data are from three independent experiments. The average profile of EGF peaks in the CK-666-treated cells is broader (less discrete) than the other treatment groups. See table in Figure EV4 for statistical information.

Article Snippet: The mCherry-RAB5 Q79L (35138, Addgene) plasmid was used to generate enlarged endosomes.

Techniques: Inhibition, Transfection, Incubation, Fluorescence, Control

Journal: bioRxiv

Article Title: Branched actin constrains endosomal cargo to control sorting and fission

doi: 10.64898/2026.03.10.710749

Figure Lengend Snippet: The degradative and retrieval subdomains on endosomes coalesce upon branched actin inhibition. (A-F) . HeLa cells were transfected with mCherry-RAB5 Q79L and were co-incubated with EGF-488 and anti-CD59 antibody for 20 min. During the last 5 min of uptake, either ( A-C ) no inhibitor or ( D-F ) 300 µM CK-666 was added to the media. Pearson’s and Manders’ correlation coefficients for each representative image are listed. (G). ImageJ was used to calculate Pearson’s correlation coefficient for 47 ROIs in the untreated group and 42 ROIs in the CK-666-treated group from three independent experiments. Statistical significance was determined using an unpaired two-tailed t -test. (H, I) . ImageJ was used to calculate Manders’ correlation coefficients (M1 and M2) for 47 ROIs in the untreated group and 42 ROIs in the CK-666-treated group from three independent experiments. Statistical significance was determined using an unpaired two-tailed t -test.

Article Snippet: The mCherry-RAB5 Q79L (35138, Addgene) plasmid was used to generate enlarged endosomes.

Techniques: Inhibition, Transfection, Incubation, Two Tailed Test