Involvement of Galectin-3 with vascular cell adhesion molecule-1 in growth regulation of mouse BALB/3T3 cells.
beta-Galactose residues on N-glycans have been implicated to be involved in growth regulation of cells. In the present study we compared the galactosylation of cell surface N-glycans of mouse Balb/3T3 cells between 30 and 100% densities and found the beta-1,4-galactosylation of N-glycans increases predominantly in a 100-kDa protein band on lectin blot analysis in combination with digestions by diplococcal beta-galactosidase and N-glycanase. When cells at 100% density were treated with jack bean beta-galactosidase, the incorporation of 5-bromodeoxyuridine into the cells was stimulated in a dose-dependent manner, suggesting the involvement of the galactose residues in growth regulation of cells. A galactose-binding protein was isolated from the plasma membranes of cells at 100% density by affinity chromatography using an asialo-transferrin-Sepharose column and found to be galectin-3 as revealed by mass spectrometric analysis. The addition of recombinant galectin-3 into cells at 50% density inhibited the incorporation of 5-bromodeoxyuridine in a dose-dependent manner, but the inhibition was prevented with haptenic sugar. An immunocytochemical study showed that galectin-3 is present at the surface of cells at 100% density but not at 30% density where it locates inside the cells. Several glycoproteins bind to a galectin-3-immobilized column, a major of which was identified as vascular cell adhesion molecule (VCAM)-1. Immunocytochemical studies showed that some galectin-3 and VCAM-1 co-localize at the surface of cells at 100% density, indicating that the binding of galectin-3 secreted from cells to VCAM-1 is one of the pathways involved in the growth regulation of Balb/3T3 cells.
Tadokoro
Tomomi
T
Laboratory of Glycobiology, Department of Bioengineering, Nagaoka University of Technology, Kamitomioka 1603-1, Nagaoka 940-2188.
Ikekita
Masahiko
M
Toda
Tosifusa
T
Ito
Hiroko
H
Sato
Takeshi
T
Nakatani
Ryunosuke
R
Hamaguchi
Yu
Y
Furukawa
Kiyoshi
K
D000818:Animals; D041702:BALB 3T3 Cells; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism*; D049109:Cell Proliferation; D037502:Galectin 3 / Q000737:chemistry / Q000378:metabolism*; D006031:Glycosylation; D051379:Mice; D043524:Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase / Q000737:chemistry; D019010:Vascular Cell Adhesion Molecule-1 / Q000737:chemistry / Q000378:metabolism*; D001616:beta-Galactosidase / Q000737:chemistry
D037502:Galectin 3; D019010:Vascular Cell Adhesion Molecule-1; D001616:beta-Galactosidase; D043524:Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase