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Updated: Jul 15, 2026
10:37
Induction and Analysis of Epithelial to Mesenchymal Transition
Published on: August 27, 2013
The epithelin precursor encodes two proteins with opposing activities on epithelial cell growth
G D Plowman1, J M Green, M G Neubauer
1Bristol-Myers Squibb Pharmaceutical Research Institute, Seattle, Washington 98121.
The Journal of Biological Chemistry
|June 25, 1992
Summary
Epithelins 1 and 2 are novel growth factors involved in epithelial homeostasis. Epithelin 1 promotes cell growth, while epithelin 2 inhibits it, suggesting a regulatory role in epithelial tissues.
Area of Science:
- Molecular Biology
- Cell Biology
- Biochemistry
Background:
- Epithelins 1 and 2 were initially identified for their growth inhibitory effects on human epidermoid carcinoma cells.
- These growth factors are polypeptides with conserved cysteine residues, suggesting structural and functional significance.
Purpose of the Study:
- To determine the complete amino acid sequences of epithelins 1 and 2.
- To clone the cDNA for these growth factors from rat, mouse, and human sources.
- To investigate the biological activities and expression patterns of epithelins.
Main Methods:
- Amino acid sequencing and cDNA cloning from multiple species.
- Recombinant protein expression in COS cells.
- Northern blot analysis to assess mRNA expression.
Main Results:
- Epithelins 1 and 2 are 56- and 57-amino acid polypeptides with 47% sequence identity and 12 conserved cysteine residues.
- Both proteins are derived from a single precursor containing multiple copies of a novel 12-cysteine motif.
- Epithelin 1 is mitogenic for rodent keratinocytes and fibroblasts, while epithelin 2 antagonizes epithelin 1's activity.
- Epithelin mRNA is broadly expressed in various epithelial cell types.
Conclusions:
- Epithelins 1 and 2 are key regulators of epithelial homeostasis due to their opposing biological activities.
- The broad expression of epithelin transcripts supports their role in maintaining epithelial tissue balance.
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