Acid Prohormone Sequence Determines Size, Shape, and Docking of Secretory Vesicles in Atrial Myocytes
| Autor: | Angela Roatti, Alex J. Baertschi, Stanislas Fakan, Dominique Monnier, Uta Schmidt, Edwin S. Levitan |
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| Rok vydání: | 2001 |
| Předmět: |
Physiology
Heart Ventricles Recombinant Fusion Proteins Green Fluorescent Proteins Protein Sorting Signals Protein aggregation Green fluorescent protein Rats Sprague-Dawley Mice Structure-Activity Relationship Animals Myocyte Heart Atria Particle Size Protein Precursors Microscopy Immunoelectron Cells Cultured Binding Sites Chemistry Myocardium Secretory Vesicles Vesicle Cell Membrane Biological Transport Fusion protein Secretory Vesicle Microspheres Rats Luminescent Proteins Membrane Animals Newborn Biochemistry Docking (molecular) Mutagenesis Site-Directed Biophysics Calcium Cardiology and Cardiovascular Medicine Atrial Natriuretic Factor Signal Transduction trans-Golgi Network |
| Zdroj: | Circulation Research. 89 |
| ISSN: | 1524-4571 0009-7330 |
| DOI: | 10.1161/hh1501.095715 |
| Popis: | How vesicles are born in the trans -Golgi network and reach their docking sites at the plasma membrane is still largely unknown and is investigated in the present study on live, primary cultured atrial cardiomyocytes. Secretory vesicles (n=422) are visualized by expressing fusion proteins of proatrial natriuretic peptide (proANP) and green fluorescent protein. Myocytes expressing fusion proteins with intact proANP display two populations of fluorescent vesicles with apparent diameters of 120 and 175 nm, moving at a top velocity of 0.3 μm/s. The number of docked vesicles is significantly correlated with the number of mobile vesicles ( r =0.71, P 23,24 →gln 23,24 ) change size and shape—but not velocity—of the vesicles, and, strikingly, abolish their docking at the plasma membrane. The shapes thus change from spheres to larger, irregular floppy bags or vesicle trains. Deletion of the C-terminal proANP[45-127], where the ANP and its disulfide bond reside, does not change size, shape, docking, or velocity of the mobile vesicles. The N-terminal acid calcium-binding sequence of proANP is known to cause protein aggregation at the high calcium concentration prevailing in the trans -Golgi network. Therefore, these results indicate that amino acid residues favoring cargo aggregation are critically important in shaping the secretory vesicles and determining their fate—docking or not docking—at the plasma membrane. The full text of this article is available at http://www.circresaha.org. |
| Databáze: | OpenAIRE |
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