J. Ochieng et al., GALECTIN-3 IS A NOVEL SUBSTRATE FOR HUMAN MATRIX METALLOPROTEINASE-2 AND METALLOPROTEINASE-9, Biochemistry, 33(47), 1994, pp. 14109-14114
The primary structure of galectin-3, a similar to 30 kDa galactoside-b
inding protein (aka CBP-35, mL-34, hL-31, L-29, Mac-2, and epsilon BP)
, reveals two structural domains: an amino-terminal domain consists of
a Pro-Gly-rich motif, and a globular carboxyl-terminal domain contain
ing a carbohydrate-binding site. In this study, we report that the ami
no-terminal domain of galectin-3 contains a cleavage site for two memb
ers of the matrix metalloproteinase family of enzymes: the 72 kDa (gel
atinase A, MMP-2) and the 92 kDa (gelatinase B, MMP-9) proteinases. Th
e major cleavage site for the gelatinases in galectin-3 is at the Ala(
62)-Tyr(63) bond, and its hydrolysis by these enzymes was inhibited by
TIMP-2. Cell-surface expression of galectin-3 was reduced following t
reatment of viable T47D human breast carcinoma cells with gelatinase A
. These results suggest that galectin-3 may be a substrate for gelatin
ases and that its degradation may play a role in modulating the biolog
ical activities of galectin-3.