The homolog of chromatin binding protein Bx42 identified in Dictyostelium.

We identified in Dictyostelium a gene snwA containing a region of similarity to SH2 domains of higher eukaryotes. snwA is homologous to a novel human gene SNW1 and to Bx42 from Drosophila melanogaster, a gene coding for a chromatin binding protein responsive to 20-OH-ecdysone. snwA has one mRNA transcript of an approximate size of 2.5 kb.

A monoclonal antibody identifies a novel GPI-anchored glycoprotein involved in epithelial intercellular adhesion.

BD31 mAb, raised against a line of gastric carcinoma cells, reacts with intercellular boundaries of human transformed cells originating from carcinomas or sarcomas growing in epithelial-like clusters as well as in primary cultures of epithelial and endothelial cells. BD31 also reacts with intercellular rims of normal and transformed epithelial tissues and is particularly abundant in glands and fast-growing epithelia but absent in nervous and muscle tissues as well as in blood and in mesenchyme-derived cells. Confocal analysis indicates that BD31 is located in dots at cell-cell contacts but not in basal and apical domains of cultured and in situ epithelial cells. mAb BD31 precipitates a 100 kDa protein from cells labeled with [35S]methionine or [3H]glucosamine as well as from 125I-surface-labeled cells. This glycoprotein resists to trypsin in the presence of Ca2+, releases an 80 kDa fragment in the medium and does not react with antibodies to the conserved cytodomain of known cadherins or, specifically, to the ectodomain of E-cadherin in western blotting; moreover, the lack of cadherin cytodomain and protein removal by phosphoinositide-specific phospholipase indicate its membrane anchoring by a glycosyl-phosphatidylinositol (GPI) moiety. BD31 IgGs do not impair cell-matrix adhesion but induce inhibition of Ca(2+)-dependent aggregation, loss of cell-cell adhesion, scattering of confluent cells and appearance of migratory cell phenotypes in a dose- and time-dependent manner. This novel GPI-anchored glycoprotein may regulate intercellular adhesion by a mechanism involving membrane-associated phospholipases.

A novel GPI-anchored glycoprotein shows properties of a COOH-terminus truncated cadherin involved in cell-cell contacts of cultured human epithelial cells.

We report the characterization of a cell-cell adhesion molecule identified by mAb BD31 on human epithelioid cells. This glycoprotein shows cadherin features but appears to be truncated being devoid of the transmembrane and cytoplasmic domains. It is directly membrane-anchored by a GPI moiety. We propose to call this molecule HT-cadherin.

A novel GPI-anchored glycoprotein shows properties of a coohterminus truncated cadherin involved in cell-cell contacts of cultured human epithelial cells.

We report the characterization of a cell-cell adhesion molecule identified by mAbBD31 on human epithelioid cells. This glycoprotein shows cadherin features but appears to be truncated being devoid of the transmembrane and cytoplasmic domains. It is directly membrane-anchored by a GPI moiety. We propose to call this molecule HT-cadherin.