Suprabasal marker proteins distinguishing keratinizing squamous epithelia: cytokeratin 2 polypeptides of oral masticatory epithelium and epidermis are different
| Autor: | Christine Collin, Christine Grund, Werner W. Franke, Jean Pierre Ouhayoun |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
Cancer Research
Immunocytochemistry Molecular Sequence Data Sequence Homology In situ hybridization Biology Epithelium Cytokeratin Keratin medicine Humans Electrophoresis Gel Two-Dimensional Amino Acid Sequence Cloning Molecular Intermediate filament Molecular Biology Peptide sequence In Situ Hybridization chemistry.chemical_classification Epidermis (botany) Base Sequence Mouth Mucosa Cell Biology DNA Blotting Northern Molecular biology Blotting Southern medicine.anatomical_structure chemistry Keratins RNA Epidermis Developmental Biology |
| Zdroj: | Differentiation; research in biological diversity. 51(2) |
| ISSN: | 0301-4681 |
| Popis: | Terminal differentiation of squamous epithelia is usually characterized by the synthesis of a subset of cytokeratins (CKs) in suprabasal cell layers which become major components of the intermediate filament (IF) bundle cytoskeleton of the maturing cells. We have examined the significance, molecular nature and pattern of synthesis of the elusive human CK 2 by analyzing mRNAs from certain stratified epithelia, using in vitro translation, cDNA cloning, Northern blotting and in situ hybridization. We show that genuine polypeptides with the typical gel electrophoretic mobility of CK 2 exist but that the CK 2 present in the masticatory epithelia of hard palate and gingiva (CK 2p) differs from that found in epidermis (CK 2e) by its amino acid sequence and is encoded by a different gene. The two CKs 2 show only limited sequence homology (71% identical amino acid positions in the rod domain), and the oral CK 2p is more closely related to the corneal CK 3 (86%), as is also indicated by the cross-reaction of monoclonal antibody AE5. By in situ hybridization and immunocytochemistry, we further show that both CK 2e and CK 2p are expressed only in suprabasal cell layers of the specific epithelia where they can accumulate to represent major cytoskeletal proteins. We discuss this tissue-type specificity of CK 2 synthesis in otherwise morphologically and biochemically similar epithelia in relation to differences of IF appearance and packing in upper strata between epidermal and masticatory epithelia as well as to tissue formation and differentiation during development. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Plný text