Journal: Cell reports
Article Title: MAL2 mediates the formation of stable HER2 signaling complexes within lipid raft-rich membrane protrusions in breast cancer cells
doi: 10.1016/j.celrep.2021.110160
Figure Lengend Snippet: (A) Immunofluorescence staining for cholera toxin B (lipid rafts) in control and trastuzumab-resistant SKBR3 cells. Scale bars represent 10 μm. (B) Immunofluorescence staining for HER2 and MAL2 in control and trastuzumab-resistant SKBR3 cells. Scale bars represent 10 μm. (C) PLA for HER2 and MAL2 in control and trastuzumab-resistant SKBR3 cells also stained for phalloidin. Scale bars represent 10 μm. (D–F) Quantitative results from immunoprecipitation coupled with data-independent acquisition mass spectrometry (DIA-MS) in control and trastuzumab-resistant SKBR3 cells. (D) The DIA-MS Intensity (log 2 ) of HER2 and MAL2 proteins from control and trastuzumab-resistant SKBR3 cells. (E) The DIA-MS Intensity (log 2 ) for all the peptide precursor signals of HER2 in control and resistant cells. (F) The DIA-MS peak groups visualized for quantifying HER2 (VLGSGAFGTVYK) and MAL2 (VTLPAGPDILR). Peaks above and below the middle line denote the MS2 and MS1 ion traces in DIA-MS. (G) MAL2, Ezrin, and NHERF1 mRNA expression in control and trastuzumab-resistant SKBR3 cells as assessed by quantitative RT-PCR (n = 3). (H) PLA for HER2 with Ezrin (left), NHERF1 (middle), and PMCA2 (right) in control and trastuzumab-resistant SKBR3 cells also stained for phalloidin. Boxed portions are amplified at right with co-registration of PLA signal and immunofluorescence for actin (phalloidin). (I) Quantitation of PLA experiment for HER2 in combination with MAL2, Ezrin, NHERF1, or PMCA2 represented as the fluorescent intensity of amplified PLA signals associated with membrane protrusions. (J) Coimmunoprecipitation for HER2 and HSP90 in control and trastuzumab-resistant SKBR3 cells. (K) PLA for HER2 and HSP90 in control and trastuzumab-resistant SKBR3 cells also stained for phalloidin. Scale bars represent 10 μm. (L) XTT cell viability assay in control, MAL2KD-treated, and MβCD-treated trastuzumab-resistant SKBR3 and BT474 cells. (M) Immunofluorescence staining for FOXO1 in control, MAL2KD-treated, and MβCD-treated trastuzumab-resistant SKBR3 cells. (N) Immunofluorescence staining for HER2 and pAKT in control, MAL2KD-treated, and MβCD-treated trastuzumab-resistant SKBR3 cells. Scale bars represent 10 μm. (O) Diagram representing the structure of MAL2- and lipid raft-enriched membrane protrusions containing multi-protein HER2 signaling complexes. These results are representative of three independent experiments.
Article Snippet: MAL2 (NM_052886) Human Tagged ORF Clone , Origene , Cat#RC203862.
Techniques: Immunofluorescence, Staining, Control, Immunoprecipitation, Data-independent acquisition, Mass Spectrometry, Expressing, Quantitative RT-PCR, Amplification, Quantitation Assay, Membrane, Viability Assay