Journal: Cancer Communications
Article Title: Cytoplasmic YAP1‐mediated ESCRT‐III assembly promotes autophagic cell death and is ubiquitinated by NEDD4L in breast cancer
doi: 10.1002/cac2.12417
Figure Lengend Snippet: YAP1 bound to VPS4B and CHMP2B and promoted CHMP2B‐VPS4B assembly. (A) PPI network of autophagy‐related genes that interact with YAP1. The three genes labeled in pink (VPS25, VPS4B, and CHMP3) belong to the ESCRT‐III complex. (B) SKBR3 cells were transfected with YAP1 overexpression plasmid, MDA‐MB‐231 cells were transfected with siYAP1 , and mRNA expression levels of ESCRT‐III subunits were determined by qRT‐PCR. (C) VPS4B and CHMP2B expression levels were detected via WB in MDA‐MB‐231 and SKBR3 cells after YAP1 overexpression. (D) Left panel: magnified view of CHMP2B‐YAP1‐VPS4B binding. The R87–P99 residues of YAP1 were embedded in the binding region of CHMP2B and VPS4B; YAP1 serves as an anchor protein, stabilizing CHMP2B‐VPS4B binding. Right panel: the side chain phenyl ring of YAP1 (F95) interacts through π stacking with the imidazole ring of VPS4B (H36) and the phenyl ring of VPS4B (Y40). The amino group of the YAP1 side chain (R87) forms a hydrogen bond with the hydroxyl group of CHMP2B (D129). (E) MDA‐MB‐231 and SKBRS parent cell lysates were immunoprecipitated with anti‐YAP1, anti‐VPS4B, or anti‐CHMP2B antibodies, and YAP1 binding to VPS4B and CHMP2B was examined with WB analysis. (F) Upper panel: IF staining shows the co‐localization and subcellular localization of YAP1 (red) and VPS4B (green) in MDA‐MB‐231 and SKBR3 cells. DAPI labelled with blue fluorescent signal was used to mark the nucleus, while red fluorescent signal was used to label YAP1 and green fluorescent signal was used to label VPS4B. Lower panel: IF staining shows the co‐localization and subcellular localization of YAP1 (green) and CHMP2B (red) in MDA‐MB‐231 and SKBR3 cells. DAPI labelled with blue fluorescent signal was used to mark the nucleus, while red fluorescent signal was used to label CHMP2B and green fluorescent signal was used to label YAP1. (G) MDA‐MB‐231 and SKBR3 cells transfected with vector control or YAP1 overexpression plasmid were immunoprecipitated with anti‐VPS4B or anti‐CHMP2B antibody, and WB analysis was used to detect CHMP2B and VPS4B. Overexpression of YAP1 increased the interactions of VPS4B and CHMP2B. (H) MDA‐MB‐231 cells transfected with negative control or siYAP1 were immunoprecipitated with anti‐VPS4B or anti‐CHMP2B antibody, and WB analysis was used to detect CHMP2B and VPS4B. Downregulation of YAP1 weakened the interaction of VPS4B and CHMP2B. (I) MCF7 cells transfected with vector control or 3 truncated mutants of YAP1 were immunoprecipitated with anti‐Flag antibody, YAP1(1‐159aa) binds to VPS4B and CHMP2B. Blue arrows represent Flag‐specific bands. (J) MCF7 cells transfected with vector control or mutants of YAP1 were immunoprecipitated with anti‐Flag antibody; YAP1(F95) binds to VPS4B, and YAP1 (R87) binds to CHMP2B. Each experiment was repeated three times, and data are shown as the mean ± standard deviation. Abbreviations: PPI, protein‐protein interaction; ESCRT, endosomal sorting complexes required for transport; YAP1, Yes1‐associated transcriptional regulator; qRT‐PCR, quantitative real‐time PCR; WB, Western blotting; IP, immunoprecipitation; VPS4B, vacuolar protein sorting 4 homolog B; CHMP2B, charged multivesicular body protein 2B; IgG, immunoglobulin G; IF, immunofluorescence staining; DAPI, 4',6‐diamidino‐2‐phenylindole.
Article Snippet: YAP1 (HG17690‐UT), CHMP2B (HG14596‐UT), and NEDD4L (HG17684‐UT) overexpression plasmids were purchased from Sino Biological Inc. (Beijing, China).
Techniques: Labeling, Transfection, Over Expression, Plasmid Preparation, Expressing, Quantitative RT-PCR, Binding Assay, Immunoprecipitation, Staining, Negative Control, Standard Deviation, Real-time Polymerase Chain Reaction, Western Blot, Immunofluorescence