Abstract
The mucus adhesion promoting protein (MapA) is considered as one of adhesion factors in Lactobacillus reuteri. Previously, two different molecules on human intestinal epithelial cells were identified as putative receptor-like molecules of MapA. In this study, the domain of MapA involved in the adhesion between the protein and Caco-2 cells was analyzed. MapA was divided into three fragments and each was tested for its binding ability. The middle region of the protein, F2, exhibited adherence to Caco-2 cells, while the other fragments showed no adhesion. By pull-down assay and western blotting analysis, Paralemmin (PALM) was estimated as a receptor-like molecule of F2. In order to confirm whether PALM is involved in the F2-Caco-2 attachment, siRNA-mediated PALM knocked down (KD) was introduced into Caco-2 cells. Expectedly, the adherence of F2 to the KD cells was significantly lower than that to the parental cells. Unlike PALM, another putative receptor-like molecule of MapA, Annexin A13 (ANX A13), did not bind to F2. These results suggest that MapA bind to PALM and ANX A13 via different mechanisms.
