TY - JOUR
T1 - Cell Cycle Regulation by Galectin-12, a New Member of the Galectin Superfamily
AU - Yang, Ri Yao
AU - Hsu, Daniel K.
AU - Yu, Lan
AU - Ni, Jian
AU - Liu, Fu Tong
PY - 2001/6/8
Y1 - 2001/6/8
N2 - Galectins are a family of β-galactoside-binding animal lectins with conserved carbohydrate recognition domains (CRDs). Here we report the identification and characterization of a new galectin, galectin-12, which contains two domains that are homologous to the galectin CRD. The N-terminal domain contains all of the sequence elements predicted to form the two β-sheets found in other galectins, as well as conserved carbohydrate-interacting residues. The C-terminal domain shows considerable divergence from the consensus sequence, and many of these conserved residues are not present. Nevertheless, the protein has lactose binding activity, most likely due to the contribution of the N-terminal domain. The mRNA for galectin-12 contains features coding for proteins with growth-regulatory functions. These include start codons in a context that are suboptimal for translation initiation and AU-rich motifs in the 3′-untranslated region, which are known to confer instability to mRNA. Galectin-12 mRNA is sparingly expressed or undetectable in many tissues and cell lines tested, but it is up-regulated in cells synchronized at the G1 phase or the G 1/S boundary of the cell cycle. Ectopic expression of galectin-12 in cancer cells causes cell cycle arrest at the G1 phase and cell growth suppression. We conclude that galectin-12 is a novel regulator of cellular homeostasis.
AB - Galectins are a family of β-galactoside-binding animal lectins with conserved carbohydrate recognition domains (CRDs). Here we report the identification and characterization of a new galectin, galectin-12, which contains two domains that are homologous to the galectin CRD. The N-terminal domain contains all of the sequence elements predicted to form the two β-sheets found in other galectins, as well as conserved carbohydrate-interacting residues. The C-terminal domain shows considerable divergence from the consensus sequence, and many of these conserved residues are not present. Nevertheless, the protein has lactose binding activity, most likely due to the contribution of the N-terminal domain. The mRNA for galectin-12 contains features coding for proteins with growth-regulatory functions. These include start codons in a context that are suboptimal for translation initiation and AU-rich motifs in the 3′-untranslated region, which are known to confer instability to mRNA. Galectin-12 mRNA is sparingly expressed or undetectable in many tissues and cell lines tested, but it is up-regulated in cells synchronized at the G1 phase or the G 1/S boundary of the cell cycle. Ectopic expression of galectin-12 in cancer cells causes cell cycle arrest at the G1 phase and cell growth suppression. We conclude that galectin-12 is a novel regulator of cellular homeostasis.
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U2 - 10.1074/jbc.M010914200
DO - 10.1074/jbc.M010914200
M3 - Article
C2 - 11283015
AN - SCOPUS:0035827555
SN - 0021-9258
VL - 276
SP - 20252
EP - 20260
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 23
ER -