Chromaffin cell F-actin disassembly and potentiation of catecholamine release in response to protein kinase C activation by phorbol esters is mediated through myristoylated alanine-rich C kinase substrate phosphorylation
| Autor: | Tatiana Lejen, Li Zhang, J.-M. Trifaró, Sergio D. Rosé |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
Chromaffin Cells
Immunoblotting macromolecular substances Biology Biochemistry chemistry.chemical_compound Catecholamines Phorbol Esters medicine Animals Secretion MARCKS Phosphorylation Protein kinase A Molecular Biology Protein kinase C Cytoskeleton Protein Kinase C Alanine Binding Sites Kinase Cell Membrane Cell Biology Precipitin Tests Actins Cell biology Protein Structure Tertiary Enzyme Activation medicine.anatomical_structure chemistry Microscopy Fluorescence Chromaffin cell Phorbol Carcinogens Tetradecanoylphorbol Acetate Calcium Cattle Electrophoresis Polyacrylamide Gel Peptides Myristic Acids Protein Binding |
| Zdroj: | The Journal of biological chemistry. 276(39) |
| ISSN: | 0021-9258 |
| Popis: | The large majority of chromaffin vesicles are excluded from the plasma membrane by a cortical F-actin network. Treatment of chromaffin cells with phorbol 12-myristate 13-acetate produces disassembly of cortical F-actin, increasing the number of vesicles at release sites (Vitale, M. L., Seward, E. P., and Trifaro, J. M. (1995) Neuron 14, 353–363). Here, we provide evidence for involvement of myristoylated alanine-rich protein kinase C substrate (MARCKS), a protein kinase C substrate, in chromaffin cell secretion. MARCKS binds and cross-links F-actin, the latter is inhibited by protein kinase C-induced MARCKS phosphorylation. MARCKS was found in chromaffin cells by immunoblotting. MARCKS was also detected by immunoprecipitation. In intact or permeabilized cells MARCKS phosphorylation increased upon stimulation with 10−7 m phorbol 12-myristate 13-acetate. This was accompanied by cortical F-actin disassembly and potentiation of secretion. MARCKS phosphorylation, cortical F-actin disassembly, and potentiation of Ca2+-evoked secretion were inhibited by a peptide (MARCKS phosphorylation site domain sequence (MPSD)) with amino acid sequence corresponding to MARCKS phosphorylation site. MPSD was phosphorylated in the process. A similar peptide (alanine-substituted phosphorylated site domain) with four serine residues of MPSD substituted by alanines was ineffective. These results provide the first evidence for MARCKS involvement in chromaffin cell secretion and suggest that regulation of cortical F-actin cross-linking might be involved in this process. |
| Databáze: | OpenAIRE |
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