Galectin-3 interacts with membrane lipids and penetrates the lipid bilayer.
The precise mechanism by which galectin-3 and other cytosolic proteins that lack signal peptides are secreted is yet to be elucidated. In the present analyses, we determined that galectin-3, a beta-galactoside binding protein, can interact directly with membrane lipids in solid phase binding assays. More interestingly, we determined by spectrophotometric methods that it can spontaneously penetrate the lipid bilayer of liposomes in either direction. These findings suggest that galectin-3 on its own has the capacity to traverse the lipid bilayer. Whereas the situation is rather simplified in liposomes, the interaction of galectin-3 with the plasma membrane may involve cholesterol-rich membrane domains where galectin-3 can be concentrated and form multimers or interact covalently with other proteins.
Lukyanov
Pavel
P
Division of Cancer Biology, Department of Biomedical Sciences, Meharry Medical College, 1005 D.B. Todd Blvd., Nashville, TN 37208, USA.
Furtak
Vyacheslav
V
Ochieng
Josiah
J
D000818:Animals; D001940:Breast / Q000378:metabolism; D001943:Breast Neoplasms / Q000378:metabolism; D002460:Cell Line; D002462:Cell Membrane / Q000737:chemistry* / Q000378:metabolism*; D002463:Cell Membrane Permeability; D037502:Galectin 3 / Q000737:chemistry* / Q000378:metabolism*; D008051:Lipid Bilayers / Q000737:chemistry* / Q000378:metabolism*; D008081:Liposomes / Q000737:chemistry*; D008560:Membrane Fluidity; D051379:Mice; D011485:Protein Binding; D021381:Protein Transport
D037502:Galectin 3; D008051:Lipid Bilayers; D008081:Liposomes