Regulation of L-selectin expression by membrane proximal proteolysis
| Autor: | T K, Kishimoto, J, Kahn, G, Migaki, E, Mainolfi, F, Shirley, R, Ingraham, R, Rothlein |
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| Rok vydání: | 1995 |
| Předmět: |
Neutrophils
Cell Membrane Molecular Sequence Data Antibodies Monoclonal Sequence Homology Enzyme-Linked Immunosorbent Assay Lymphocyte Activation Peptide Fragments N-Formylmethionine Leucyl-Phenylalanine Endopeptidases Humans Tetradecanoylphorbol Acetate Protease Inhibitors Amino Acid Sequence Lymphocytes L-Selectin Cell Adhesion Molecules Immunosorbent Techniques |
| Zdroj: | Agents and actions. Supplements. 47 |
| ISSN: | 0379-0363 |
| Popis: | L-selectin is a lectin cell adhesion molecule expressed on the cell surfaces of lymphocytes, monocytes and granulocytes. Upon leukocyte activation or L-selectin cross-linking the transmembrane-bound L-selectin is rapidly shed from the cell surface. Based on these observations, it has been proposed that L-selectin is proteolytically cleaved from the cell surface. However a panel of common protease inhibitors have no effect on L-selectin proteolysis. To further define the mechanism of L-selectin down-regulation we have produced reagents to study proteolytic fragments of L-selectin. We have developed a trapping ELISA for the detection of soluble L-selectin. In addition we have produced a high affinity polyclonal antisera against the extracellular domain and against the cytoplasmic domain of L-selectin. Both antisera immunoprecipitate the intact form of L-selectin from metabolically labeled PHA lymphoblasts and peripheral blood neutrophils. We review here our progress in defining a 6 kD L-selectin transmembrane peptide (L-STMP) from PMA activated lymphoblasts and fMLP-activated neutrophils. Radiochemical sequencing data indicate that the cleavage site occurs between Lys321 and Ser322 in a short membrane-proximal region of the extracellular domain. |
| Databáze: | OpenAIRE |
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