Cleavage of A-CAM by endogenous proteinases in cultured lens cells and in developing chick embryos
| Autor: | Tova Volberg, Talila Volk, Benjamin Geiger, Ilana Sabanay |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
animal structures
Proteolysis Molecular Sequence Data Cell Fluorescent Antibody Technique Endogeny Antigen-Antibody Complex Chick Embryo Cleavage (embryo) Antibodies Chromatography Affinity Cell–cell interaction Lens Crystalline medicine Animals Trypsin Amino Acid Sequence Molecular Biology medicine.diagnostic_test biology Cell adhesion molecule Cell Biology Cadherins Cell biology Molecular Weight Microscopy Electron medicine.anatomical_structure Biochemistry Cell culture biology.protein Antibody Peptide Hydrolases Developmental Biology |
| Zdroj: | Developmental Biology. 139:314-326 |
| ISSN: | 0012-1606 |
| DOI: | 10.1016/0012-1606(90)90301-x |
| Popis: | We describe two truncated forms of A-CAM (N-cadherin) and present evidence suggesting that both forms are proteolytically derived from the intact A-CAM molecule. The first is a membrane-bound fragment of A-CAM displaying an apparent molecular weight of 78 kDa. This polypeptide, containing the C-terminal portion of the protein, may be generated in cultured chicken lens cells, either by a short treatment with trypsin-EGTA, or by endogenous proteinase(s) during incubation in low Ca2+ medium. Immunofluorescent labeling of normal and EGTA-treated cells indicated that the 78-kDa fragment is uniformly distributed over the cell surface. Moreover, staining of developing chick embryos with pairs of antibodies which distinguish the 78-kDa fragment from intact A-CAM indicated that, at early stages of sclerotome dissociation in developing somites, a truncated derivative of the molecule is generated. The second truncated form of A-CAM is a 97-kDa polypeptide which is constitutively released by cultured lens cells into the culture medium in the presence of normal medium. We present evidence that the 97-kDa molecule is proteolytically derived from A-CAM by the action of an endogenous proteinase. We discuss possible mechanisms leading to the formation of these two truncated derivatives and their possible involvement in the physiological modulation of A-CAM-mediated interactions. |
| Databáze: | OpenAIRE |
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