Genetic evidence for a novel human desmosomal cadherin, desmoglein 4.
Desmosomes are essential adhesion structures in most epithelia that link the intermediate filament network of one cell to its neighbor, thereby forming a strong bond. The molecular components of desmosomes belong to the cadherin superfamily, the plakin family, and the armadillo repeat protein family. The desmosomal cadherins are calcium-dependent transmembrane adhesion molecules and comprise the desmogleins and desmocollins. To date, three human desmoglein isoforms have been characterized, namely desmogleins 1, 2, and 3 that are expressed in a tissue- and differentiation-specific manner. Here we have identified and characterized, at the genetic level, a novel human desmoglein cDNA sharing homology with desmogleins 1, 2, 3 and we name this desmoglein 4. The human desmoglein 4 cDNA (3.6 kb) contains an open reading frame of 3120 bp that encodes a precursor protein of 1040 amino acids. The predicted mature protein comprises 991 amino acids with a molecular weight of 107822 Da at pI 4.38. Human desmoglein 4 shares 41% identity with human desmoglein 1, 37% with human desmoglein 2, and 50% with human desmoglein 3. Analysis of the exon/intron organization of the human desmoglein 4 gene (DSG4) demonstrates that it is composed of 16 exons spanning approximately 37 kb of 18q12 and is situated between DSG1 and DSG3. We have demonstrated using RT-PCR on multiple tissue cDNA samples that desmoglein 4 has very specific tissue expression in salivary gland, testis, prostate, and skin.
Whittock
Neil V
NV
Institute of Biomedical and Clinical Science, Peninsula Medical School, Exeter, United Kingdom. nwhittoc@hgmp.mrc.ac.uk
Bower
Christopher
C
D000595:Amino Acid Sequence; D001483:Base Sequence; D015820:Cadherins / Q000235:genetics*; D003598:Cytoskeletal Proteins / Q000235:genetics*; D018076:DNA, Complementary / Q000235:genetics; D051184:Desmoglein 3; D051182:Desmogleins; D003896:Desmosomes / Q000737:chemistry* / Q000502:physiology*; D005786:Gene Expression Regulation; D006801:Humans; D008969:Molecular Sequence Data; D010392:Pemphigus / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction
D015820:Cadherins; D003598:Cytoskeletal Proteins; D018076:DNA, Complementary; C071894:DSG3 protein, human; C473409:DSG4 protein, human; D051184:Desmoglein 3; D051182:Desmogleins