B. Schlosshauer et al., NEUROTHELIN - AMINO-ACID-SEQUENCE, CELL-SURFACE DYNAMICS AND ACTIN COLOCALIZATION, European journal of cell biology, 68(2), 1995, pp. 159-166
Neurothelin is a cell surface protein of chicken endothelial cells at
the blood-brain barrier and also of pigment epithelial cells forming t
he blood-eye barrier. Peptide sequencing of affinity-purified neurothe
lin revealed that it is likely to be identical with the protein called
HT7. It belongs to the immunoglobulin superfamily having two extracel
lular CZ-type domains, a membrane spanning region and a cytoplasmic ta
il. During development neurothelin cell surface localization changed o
n pigment epithelial cells. In early embryogenesis neurothelin was fou
nd preferentially at lateral sites of neighboring epithelial cells, bu
t after hatching, predominantly on basal cell surfaces and on apical m
icrovilli of epithelial cells that contact retinal photoreceptors. Dis
ruption of cell-cell contacts induced a rapid change of neurothelin di
stribution on the cell surface in vitro as could be shown by confocal
laser microscopy Disintegration of microfilaments by cytochalasin D ha
mpered this specific cell surface rearrangement of neurothelin, wherea
s depolymerization of microtubules by demecolcine had no effect, In do
uble-labeling experiments neurothelin and F-actin were colocalized. Th
e data suggest that the polarized cell surface distribution of neuroth
elin is influenced intracellularly by F-actin and extracellularly by c
ell-cell interactions.