Figure 1.

PTP1B associates with IL13Rα2. (A) Protein interaction network for IL13Rα2 in U251 cells was identified by mass spectrometry analysis. Protein position was tentatively assigned based on the existing literature. (B) Western blot analysis of the expression of PTP1B in human CRC, OC and GMB cell lines and PDXs (GBM43 and GBM6). (C) Western blot analysis of IL13Rα2 (top) and PTP1B (bottom) co-immunoprecipitated proteins in the indicated cell lines. (D) PEP-FOLD3 representation of IL13Rα2 cytoplasmic tail structure showing the Tyr₃₆₉ location. Colorectal RKO cancer cells transfected with empty vectors (mock) or vectors encoding for wild type IL13Rα2 or Y369F mutated form were lysed and subjected to (E) Western blot analysis to verify the expression of PTP1B and IL13Rα2 forms and (F) IL13Rα2 immunoprecipitation for the detection of coimmunoprecipitated PTP1B. (G) The same RKO transfectants were subjected to invasion through Matrigel. Whereas IL-13 promoted cell invasion of IL13Rα2 WT cells (*** p < 0.001), the Tyr₃₆₉ mutant significantly inhibited the invasion (◊◊◊ p < 0.001).