cDNA and protein sequence, genomic organization, and analysis of cis regulatory elements of mouse and human PLVAP genes.

PV-1 is a novel protein component of the endothelial fenestral and stomatal diaphragms. PV-1 cDNA and protein sequences are highly conserved across species. The conserved extracellular domain features found in rat, mouse, and human PV-1 protein are four N-glycosylation sites, two coiled-coil domains, a proline-rich region, and even cysteine spacing.

Endothelial transcytotic machinery involves supramolecular protein-lipid complexes.

We have demonstrated that the plasmalemmal vesicles (caveolae) of the continuous microvascular endothelium function as transcytotic vesicular carriers for protein molecules > 20 A and that transcytosis is an N-ethylmaleimide-sensitive factor (NSF)-dependent, N-ethylmaleimide-sensitive process. We have further investigated NSF interactions with endothelial proteins to find out 1) whether a complete set of fusion and targeting proteins is present in the endothelium; 2) whether they are organized in multimolecular complexes as in neurons; and 3) whether the endothelial multimolecular complexes differ from their neuronal counterparts, because of their specialized role in transcytosis. To generate the complexes, we have used myc-NSF, cultured pulmonary endothelial cells, and rat lung cytosol and membrane preparations; to detect them we have applied coimmunoprecipitation with myc antibodies; and to characterize them we have used velocity sedimentation and cross-linking procedures.