Signature sequences for the galectin-4 subfamily

Galectins are a distinct family of animal lectins that have a cation-indepe ndent affinity for beta-galactoside sugars and share characteristic amino a cid sequences, The cDNA encoding rabbit bladder galectin-4 has been cloned and sequenced (GenBank accession no. AF091738). The deduced 328 amino acid sequence predicts a multidomain structure consisting of an N-terminal pepti de (19 residues) and two carbohydrate recognition domains (130 residues eac h) connected by a linker region (49 residues). Comparison of rabbit galecti n-4 with related proteins reveals that two peptide motifs, M-A-F/Y-V-P-A-P- G-Y-Q-P-T-Y-N-P-T-L-P in the N terminus and A-F-H-F-N-P-R-F-D-G-W-D-K-V-V-F in the first carbohydrate recognition domain are highly conserved in human , pig, rat, and mouse galectin-4 as well as in mouse galectin-6. The two pe ptide motifs are proposed here as the signature sequences to identify new m embers of the galectin-4 subfamily.