P-Cadherin is a specific calcium ion-dependent cell adhesion molecule. The Ca2+-dependent cell adhesion molecules, termed cadherins, were originally divided into two subclasses, E- and
N-types, with different adhesive specificity. Nose et al identified a novel class of cadherin, termed P-cadherin.
This gene is a classical cadherin from the cadherin superfamily. The encoded protein is a calcium-dependent cell-cell adhesion glycoprotein comprised of five extracellular cadherin repeats, a transmembrane region and a highly conserved cytoplasmic tail. This gene is located in a six-cadherin cluster in a region on the long arm of chromosome 16 that is involved in loss of heterozygosity events in breast and prostate cancer. In addition, aberrant expression of this protein is observed in cervical adenocarcinomas.
Cell adhesion molecule
Expression of cadherin molecules was
demonstrated by Rufas et al in human oocyte using an anti-pan-cadherin antibody and
specific antibodies against the three classical cadherins: E- (epithelial),
P- (placental) and N- (neural) cadherins. Samples of
48 h old unfertilized oocytes were lysed and separated by
electrophoresis. Localization of cadherins was determined on intact, fixed,
permeabilized oocytes by
immunocytochemisty assessed by confocal microscopy. Immunoblotting with the
pan-cadherin antibody revealed a single
band of ~120 kDa in oocyte extracts. Oocytes presented all three classical cadherins with the appropriate molecular weights of 120130
kDa. Following immunocytochemistry of human oocytes all cadherin
molecules were allocated predominantly to the
plasma membrane with only traces in the cytoplasm. It was concluded that cadherin
molecules are present on plasma membranes of both human spermatozoa and
oocytes and may play a role in the intricate
recognition process preceding gamete fusion.