title: E-cadherin intron 2 contains cis-regulatory elements essential for gene expression.
abstract: Cadherin-mediated cell-cell adhesion plays important roles in mouse embryonic development, and changes in cadherin expression are often linked to morphogenetic events. For proper embryonic development and organ formation, the expression of E-cadherin must be tightly regulated. Dysregulated expression during tumorigenesis confers invasiveness and metastasis. Except for the E-box motifs in the E-cadherin promoter, little is known about the existence and location of cis-regulatory elements controlling E-cadherin gene expression. We have examined putative cis-regulatory elements in the E-cadherin gene and we show a pivotal role for intron 2 in activating transcription. Upon deleting the genomic intron 2 entirely, the E-cadherin locus becomes completely inactive in embryonic stem cells and during early embryonic development. Later in development, from E11.5 onwards, the locus is activated only weakly in the absence of intron 2 sequences. We demonstrate that in differentiated epithelia, intron 2 sequences are required both to initiate transcriptional activation and additionally to maintain E-cadherin expression. Detailed analysis also revealed that expression in the yolk sac is intron 2 independent, whereas expression in the lens and the salivary glands absolutely relies on cis-regulatory sequences of intron 2. Taken together, our findings reveal a complex mechanism of gene regulation, with a vital role for the large intron 2.
authors.affiliation: Department of Molecular Embryology, Max-Planck Institute of Immunobiology, Stuebeweg 51, D-79108 Freiburg, Germany.
authors.forename: Marc P
authors.initials: MP
authors.lastname: Stemmler
authors.forename: Andreas
authors.initials: A
authors.lastname: Hecht
authors.forename: Rolf
authors.initials: R
authors.lastname: Kemler
mesh_terms: D000483:Alleles; D020816:Amino Acid Motifs; D000818:Animals; D015820:Cadherins / Q000235:genetics* / Q000378:metabolism; D002448:Cell Adhesion; D002465:Cell Movement; D018450:Disease Progression; D004848:Epithelium / Q000196:embryology* / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D017930:Genes, Reporter; D007438:Introns; D007908:Lens, Crystalline / Q000196:embryology; D051379:Mice; D008822:Mice, Transgenic; D008954:Models, Biological; D008957:Models, Genetic; D009369:Neoplasms / Q000378:metabolism; D017434:Protein Structure, Tertiary; D012045:Regulatory Sequences, Nucleic Acid; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D015017:Yolk Sac / Q000378:metabolism; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: D015820:Cadherins; D001616:beta-Galactosidase