Galectin-3 binding protein promotes cell motility in colon cancer by stimulating the shedding of protein tyrosine phosphatase kappa by proprotein convertase 5

► The ectodomain of PTPκ is cleaved by a processed form of proprotein convertase 5 (PC5A) in WiDr colon cancer cells. ► Galectin-3 binding protein facilitates PTPκ shedding by decreasing the availability of cell surface-bound galectin-3. ► Galectin-3 binding protein promotes cancer cell migration by activating the PTPk shedding. ► The ratio of galectin-3 binding protein to galectin-3 can be a molecular indicator for colon cancer progression.