Desmosomes are a type of plaque-coated adhering junction. Mertens et al. (1996) isolated cDNAs
encoding 2 forms of plakophilin-2 (PKP2), which they named PKP2a and PKP2b, from human colon carcinoma and
heart cDNA libraries. The predicted 837-amino acid PKP2a protein contains 9 complete copies of the armadillo motif,
which is an approximately 42-amino acid domain first defined in the Drosophila 'armadillo' gene product. Compared
with PKP2a, the predicted 881-amino acid PKP2b protein contains an insertion of 44 amino acids between the second
and third armadillo motifs.
Immunolocalization studies showed that PKP2 is a constituent of the
desmosomal plaque in simple epithelia, some stratified epithelia, and some nonepithelial cells. PKP2 is also enriched
in the karyoplasm of cells of various types, including those lacking desmosomes. Northern blot analysis detected
approximately 5.3-kb PKP2 transcripts in diverse human cell lines and tissues representing both epithelial and
nonepithelial cells.
General function
Cell adhesion molecule
Comment
Cellular localization
Plasma membrane
Comment
Ovarian function
Oogenesis
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Expression regulated by
Comment
Ovarian localization
Oocyte
Comment
Oocyte developmental competence was predicted on the basis of the
morphological appearance of their originating ovary as previously established and were divided into groups H (high competence) and L (low
competence) by Brevini-Gandolfi TA, et al. . The length of the poly(A) tail of the following genes, beta-actin (beta-Act), connexin 43,
glucose transporter type 1, heat shock protein 70, oct-4, plakophilin, pyruvate dehydrogenase
phosphatase (PDP), and RNA poly(A) polymerase, was determined at the germinal vesicle (GV) and
metaphase II (MII) stage. The results indicated that the poly(A) tail of all genes except for beta-Act and
PDP, is shorter after in vitro maturation (IVM) in both groups.