MDCKII cells differentiate into a simple columnar epithelium when grown on a permeable support; the monolayer is polarized for transport and secretion. Individual cells within the monolayer continue to divide at a low rate without disturbing the function of the epithelium as a barrier to solutes. This presents an interesting model for the study of mitosis in a differentiated epithelium which we...

Human milk fat globule membrane, which is said to derive from apical plasma membrane of secretory epithelial cells in breast, was analyzed by sodium dodecyl sulfate-two:dimensional gel electrophoresis. More than 35 components were detected in the gels. One of the major glycoproteins with an apparent molecular weight of 70,000, human milk fat globule membrane glycoprotein, was purified to homoge...

A membrane fraction enriched in apical endosomal tubules was isolated from absorptive cells of suckling rat ileum and used as an immunogen to generate anti-endosome monoclonal antibodies. By immunofluorescence, one of these antibodies bound exclusively to the region of the apical endocytic complex in ileal absorptive cells, but not to other cell types. Immunoblot analysis showed the antigen as ...

In this study, we have investigated the possibility that glycosyl-phosphatidylinositol (GPI)-anchored proteins form insoluble membrane complexes in Caco-2 cells and that transmembrane proteins are associated with these complexes. GPI-anchored proteins were mainly resistant to Triton X-100 (TX-100) extraction at 4 degrees C but fully soluble in n-octyl-glucoside. Resistance to Triton X-100 extra...

Prostate-specific membrane antigen (PSMA) is a protein up-regulated in the vast majority of prostate cancers. Antibodies to PSMA have proved highly specific for prostate cancer cells, and the therapeutic potential of such antibodies is currently being assessed in clinical trials. We have previously shown that PSMA at the cell surface of polarized epithelial cells is predominantly expressed at t...