Involvement of blood-group-B-active trisaccharides in Ca2+-dependent cell-cell adhesion in the Xenopus blastula

Dev Genes Evol. 1998 Mar;208(1):9-18. doi: 10.1007/s004270050148.

Abstract

Despite their wide distribution in various organisms, no physiological roles have been proposed for the human blood-group-ABO (ABH)-active trisaccharides. Here we show that monoclonal antibodies against human blood-group-B-active trisaccharides (B-substance) completely block the Ca2+-dependent cell-cell adhesion system of frog (Xenopus laevis) embryonic cells. Synthetic B-substance or B-active glycopeptides also disrupt the Ca2+ -dependent cell-cell adhesion. These results suggest that blood-group-B-active substances play a role in cell-cell adhesion. Blood-group-B-active substances were found as glycoproteins and as glycosphingolipids. In order to identify B-active glycoproteins active in cell-cell adhesion, we purified B-active membrane glycoproteins by two-dimensional electrophoresis and found that they are 45- to 58-kDa proteins with pI(s) ranging from 4.0 to 5.3. They are glycosylphosphatidyl inositol (GPI) anchored. Amino acid sequence analysis showed that the purified B-active GPI-anchored proteins are homologues of soluble Xenopus cortical granule lectins (CGL). The results suggest that the B-active membrane glycoproteins are GPI-anchored forms of the lectin and are directly involved in frog Ca 2+-dependent cell-cell adhesion.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ABO Blood-Group System / immunology*
  • Amino Acid Sequence
  • Animals
  • Blastocyst / immunology*
  • Calcium / physiology*
  • Cell Adhesion / drug effects
  • Cell Adhesion / immunology
  • Cell Communication / drug effects
  • Cell Communication / immunology*
  • Glycoconjugates / immunology
  • Glycoconjugates / metabolism
  • Glycosylphosphatidylinositols / metabolism
  • Humans
  • Isoantibodies / pharmacology
  • Molecular Sequence Data
  • Phosphatidylinositol Diacylglycerol-Lyase
  • Sequence Analysis
  • Trisaccharides / immunology*
  • Trisaccharides / pharmacology
  • Type C Phospholipases / pharmacology
  • Xenopus laevis / embryology
  • Xenopus laevis / immunology

Substances

  • ABO Blood-Group System
  • Glycoconjugates
  • Glycosylphosphatidylinositols
  • Isoantibodies
  • Trisaccharides
  • Type C Phospholipases
  • Phosphatidylinositol Diacylglycerol-Lyase
  • Calcium