Fig. 6: Glycan interaction with ErbB4 JM-a.

a Interactions of peptides derived from JM-a- or JM-b-specific sequences with glycans in a mammalian glycan array from CFG. For details, see Supplementary Fig. 13. b An example of a structure of a complex type N-glycan. Core structure and binding sites for indicated lectins are shown. c, d Densitometric quantifications (mean ± SEM) of data from Western analyses of STAT5a (c) and STAT5b (d) phosphorylation (on Y694/699) in COS-7 cells expressing ErbB4 JM-a (c) or JM-b (d). Cells were treated or not with the indicated lectins and stimulated with NRG1. n = 3–5 independent experiments. One way ANOVA. e, f Growth of serum-starved HC11 cells cultured in the presence of the indicated lectin and either NRG-1 (e) or insulin (f). Cell confluence was measured using live cell imaging with IncuCyte. ***P < 0.001 as compared to the treatment with ligand in the absence of lectin. n = 18–27 wells examined over three independent experiments. Brown–Forsyte and Welch ANOVA. g Mass-spectrometry analysis of proteins interacting with biotinylated PHA-L lectin in the indicated cell lines. h, i Proximity ligation assay (PLA) of association of wild-type (wt) or H631E mutant ErbB4 JM-a with endogenous β1 integrin in COS-7 cells treated or not with DSL or STL. Quantification of the data is shown in panel i. n = 12–15 cells examined over two independent experiments. Kruskal-Wallis ANOVA. Benjamini, Krieger, and Yekutieli adjusted P-values. j, k STED super-resolution immunofluorescence analysis of colocalization of endogeously expressed β1 integrin (green) and ectopically expressed wild-type or H631E mutant ErbB4 JM-a (red) in COS-7 cells treated or not with the indicated lectins. The boxes highlight regions of interest that are magnified below. Panel k depicts the quantification of co-localization of ErbB4- and β1 integrin-specific signals at the cell surface where each dot represents the correlation of the signals in one cell. n = 14 cells examined over two independent experiments. One-way ANOVA. Benjamini, Krieger, and Yekutieli adjusted P-values. In the boxplots the line represents the median, the box the interquartile range and whiskers the whole range of values. P-values were Benjamini, Krieger, and Yekutieli adjusted. Source data are provided as a Source Data file.