Identification of Galectin-2–Mucin Interaction and Possible Formation of a High Molecular Weight Lattice

Abstract

Galectins comprise a group of animal lectins characterized by their specificity for β-galactosides. Galectin-2 (Gal-2) is predominantly expressed in the gastrointestinal tract and has been identified as one of the main gastric mucosal proteins that are proposed to have a protective role in the stomach. As Gal-2 is known to form homodimers in solution, this may result in crosslinking of macromolecules with the sugar structures recognized by Gal-2. In this study, we report that Gal-2 could interact with mucin, an important component of gastric mucosa, in a β-galactoside-dependent manner. Furthermore, Gal-2 and mucin could form an insoluble precipitate, potentially through the crosslinking of mucins via Gal-2 and the formation of a lattice, resulting in a large insoluble complex. Therefore, we suggest that Gal-2 plays a role in the gastric mucosa by strengthening the barrier structure through crosslinking the mucins on the mucosal surface.

Structural mechanisms for the S‐nitrosylation‐derived protection of mouse galectin‐2 from oxidation‐induced inactivation revealed by NMR

“…Since Gal‐2 was identified in a screen of mouse gastric mucosal proteins that are uniquely sensitive to S‐nitrosylation , S‐nitrosylation of the sulfhydryl group of C57 may be important for maintaining the function of mGal‐2 in the oxidizing environment of the gastrointestinal tract. Recently, we reported that Gal‐2 could interact with mucin, an important component of gastric mucosa, in a β‐galactoside‐dependent manner and suggested that Gal‐2 plays a role in the gastric mucosa by strengthening the barrier structure through cross‐linking the mucins on the mucosal surface . It has been proposed that galectin‐3 interacts with the O‐glycans of mucins and forms a highly organized and protective cell surface lattice barrier on the apical glycocalyx of ocular surface epithelial cells .…”

Galectin-2 suppresses nematode development by binding to the invertebrate-specific galactoseβ1-4fucose glyco-epitope

“…In addition, local galectin concentrations may be high at infection sites because the galectins are locally secreted by cells as they are being destroyed by infection (Sato et al 2009). Under physiological conditions, Gal-2 may collaborate with other proteins such as mucin (Tamura et al 2017) which is important in host defense against parasitic nematodes (Hasnain et al 2013). This cooperation could enhance Gal-2 activity against C. elegans.…”

Pregnancy Galectinology: Insights Into a Complex Network of Glycan Binding Proteins

“…Lgals2 is predominantly expressed in the gastrointestinal tract and has been identified as one of the main gastric mucosal proteins proposed to have a protective role in the stomach by interacting with mucins (111). In addition, immune functions of Lgals2 have been proposed including its ability to induce apoptosis in activated CD8 + T-cells and its effects on monocytes (112, 113).…”