Galectin-4 Binds to Sulfated Glycosphingolipids and Carcinoembryonic Antigen in Patches on the Cell Surface of Human Colon Adenocarcinoma Cells

• Published in: The Journal of biological chemistry Vol. 280; no. 6; pp. 4730 - 4737
• Main Authors: Ideo, Hiroko, Seko, Akira, Yamashita, Katsuko
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 11.02.2005; American Society for Biochemistry and Molecular Biology
• Subjects: Adenocarcinoma - metabolism; Carbohydrate Sequence; Carbohydrates - chemistry; Carcinoembryonic Antigen - chemistry; Cell Adhesion; Cell Line, Tumor; Colonic Neoplasms - metabolism; Enzyme-Linked Immunosorbent Assay; Galectin 4 - chemistry; Galectin 4 - metabolism; Glutathione Transferase - metabolism; Glycolipids - chemistry; Glycosphingolipids - chemistry; Humans; Immunohistochemistry; Immunoprecipitation; Kinetics; Ligands; Microscopy, Confocal; Microscopy, Fluorescence; Molecular Sequence Data; Protein Binding; Protein Structure, Tertiary; Sulfur - chemistry; Surface Plasmon Resonance; Time Factors
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M410362200

Galectin-4, a member of the galectin family, is expressed in the epithelium of the alimentary tract. It has two tandemly repeated carbohydrate recognition domains and specifically binds to an SO3−→3Galβ1→3GalNAc pyranoside with high affinity (Ideo, H., Seko, A., Ohkura, T., Matta, K. L., and Yamashita, K. (2002) Glycobiology 12, 199–208). In this study, we found that galectin-4 binds to glycosphingolipids carrying 3-O-sulfated Gal residues, such as SB1a, SM3, SM4s, SB2, SM2a, and GM1, but not to glycosphingolipids with 3-O-sialylated Gal, such as sLc4Cer, snLc4Cer, GM3, GM2, and GM4, using both an enzyme-linked immunosorbent assay and a surface plasmon resonance assay. A confocal immunocytochemical assay showed that galectin-4 was colocalized with SB1a, GM1, and carcinoembryonic antigen (CEA) in the patches on the cell surface of human colon adenocarcinoma CCK-81 and LS174T cells. This localization was distinct from caveolin/VIP21 localization. Furthermore, immobilized galectin-4 promoted adhesion of CCK-81 cells through the sulfated glycosphingolipid, SB1a. CEA also bound to galectin-4 with KD value of 2 × 10-8m by surface plasmon resonance and coimmunoprecipitated with galectin-4 in LS174T cell lysates. These findings suggest that SB1a and CEA in the patches on the cell surface of human colon adenocarcinoma cells could be biologically important ligands for galectin-4.