Galectin-3 modulates the polarized surface delivery of β1-integrin in epithelial cells

• Published in: Journal of cell science Vol. 131; no. 11; p. jcs213199
• Main Authors: Hönig, Ellena, Ringer, Karina, Dewes, Jenny, von Mach, Tobias, Kamm, Natalia, Kreitzer, Geri, Jacob, Ralf
• Format: Journal Article
• Language: English
• Published: England The Company of Biologists Ltd 01.06.2018
• Subjects: Cell proliferation; Cell surface; Epithelial cells; Galectin-3; Glycoproteins; Integrins; Machinery and equipment; Morphogenesis; Organelles; Sodium; Supplements; Endocytosis; Apical transport; Cell polarity; Galectin-3; Beta1-integrin
• ISSN: 0021-9533; 1477-9137
• DOI: 10.1242/jcs.213199

Epithelial cells require a precise intracellular transport and sorting machinery in order to establish and maintain their polarized architecture. This machinery includes beta-galactoside binding galectins for glycoprotein targeting to the apical membrane. Galectin-3 sorts cargo destined for the apical plasma membrane into vesicular carriers. After delivery of cargo to the apical milieu, galectin-3 recycles back into sorting organelles. We analyzed the role of galectin-3 in the polarized distribution of β1-integrin in MDCK cells. Integrins are located primarily at the basolateral domain of epithelial cells. We demonstrate that a minor pool of β1-integrin interacts with galectin-3 at the apical plasma membrane. Knockdown of galectin-3 decreases apical delivery of β1-integrin. This loss is restored by supplementation with recombinant galectin-3 and galectin-3 overexpression. Our data suggest that galectin-3 targets newly synthesized β1-integrin to the apical membrane and promotes apical delivery of β1-integrin internalized from the basolateral membrane. In parallel, galectin-3 knockout results in a reduction in cell proliferation and an impairment in proper cyst development. Our results suggest that galectin-3 modulates the surface distribution of β1-integrin and affects the morphogenesis of polarized cells.