Galectin-12, an Adipose-expressed Galectin-like Molecule Possessing Apoptosis-inducing Activity

• Published in: The Journal of biological chemistry 2001-09, Vol.276 (36), p.34089-34097
• Main Authors: Hotta, Kikuko, Funahashi, Tohru, Matsukawa, Yuko, Takahashi, Masahiko, Nishizawa, Hitoshi, Kishida, Ken, Matsuda, Morihiro, Kuriyama, Hiroshi, Kihara, Shinji, Nakamura, Tadashi, Tochino, Yoshihiro, Bodkin, Noni L., Hansen, Barbara C., Matsuzawa, Yuji
• Format: Article
• Language: English
• Subjects: 3T3 Cells; Adipocytes - metabolism; Amino Acid Sequence; Animals; Apoptosis; Base Sequence; Blotting, Northern; Cell Cycle Proteins - chemistry; Cell Cycle Proteins - metabolism; Cell Nucleus - metabolism; COS Cells; DNA, Complementary - metabolism; Galactosides - metabolism; Galectin-12; Galectin-8; Galectins; Gene Library; Hemagglutinins - chemistry; Humans; Immunohistochemistry; Lectins - chemistry; Lectins - metabolism; Macaca mulatta; Male; Mice; Mice, Inbred C57BL; Molecular Sequence Data; Protein Binding; Protein Biosynthesis; Protein Structure, Tertiary; Rats; Rats, Zucker; Recombinant Proteins - metabolism; RNA, Messenger - metabolism; Sequence Homology, Amino Acid; Thiazoles - pharmacology; thiazolidinedione; Thiazolidinediones; Tissue Distribution; Transfection; troglitazone
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M105097200

Galectins constitute a family of proteins that bind to β-galactoside residues and have diverse physiological functions. Here we report on the identification of a galectin-like molecule, galectin-12, in a human adipose tissue cDNA library. The protein contained two potential carbohydrate-recognition domains with the second carbohydrate-recognition domain being less conserved compared with other galectins. In vitro translated galectin-12 bound to a lactosyl-agarose column far less efficiently than galectin-8. Galectin-12 mRNA was predominantly expressed in adipose tissue of human and mouse and in differentiated 3T3-L1 adipocytes. Caloric restriction and treatment of obese animals with troglitazone increased galectin-12 mRNA levels and decreased the average size of the cells in adipose tissue. The induction of galectin-12 expression by the thiazolidinedione, troglitazone, was paralleled by an increase in the number of apoptotic cells in adipose tissue. Immunocytochemical analysis revealed that galectin-12 was localized in the nucleus of adipocytes, and transfection with galectin-12 cDNA induced apoptosis of COS-1 cells. These results suggest that galectin-12, an adipose-expressed galectin-like molecule, may participate in the apoptosis of adipocytes.