The vinculin/sarcomeric-alpha-actinin/alpha-actin nexus in cultured cardiac myocytes
| Autor: | S. Holtzer, D. A. Fischman, T. Schultheiss, John M. Murray, Camille DiLullo, Howard Holtzer, James J. Choi, Mei-Hua Lu |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
Sarcomeres
Talin Integrins animal structures Stress fiber Chick Embryo macromolecular substances Sarcomere medicine Animals Actinin Cells Cultured Actin biology Myocardium Articles Cell Biology Vinculin Blotting Northern musculoskeletal system Molecular biology Actins Cell biology Caldesmon Actinin alpha 1 medicine.anatomical_structure Microscopy Fluorescence biology.protein Calmodulin-Binding Proteins Myofibril Intercalated disc |
| Zdroj: | The Journal of Cell Biology |
| ISSN: | 1540-8140 0021-9525 |
| DOI: | 10.1083/jcb.117.5.1007 |
| Popis: | Experiments are described supporting the proposition that the assembly of stress fibers in non-muscle cells and the assembly of myofibrils in cardiac cells share conserved mechanisms. Double staining with a battery of labeled antibodies against membrane-associated proteins, myofibrillar proteins, and stress fiber proteins reveals the following: (a) dissociated, cultured cardiac myocytes reconstitute intercalated discs consisting of adherens junctions (AJs) and desmosomes at sites of cell-cell contact and sub-sarcolemmal adhesion plaques (SAPs) at sites of cell-substrate contact; (b) each AJ or SAP associates proximally with a striated myofibril, and conversely every striated myofibril is capped at either end by an AJ or a SAP; (C) the invariant association between a given myofibril and its SAP is especially prominent at the earliest stages of myofibrillogenesis; nascent myofibrils are capped by oppositely oriented SAPs; (d) the insertion of nascent myofibrils into AJs or into SAPs invariably involves vinculin, alpha-actin, and sarcomeric alpha-actinin (s-alpha-actinin); (e) AJs are positive for A-CAM but negative for talin and integrin; SAPs lack A-CAM but are positive for talin and integrin; (f) in cardiac cells all alpha-actinin-containing structures invariably are positive for the sarcomeric isoform, alpha-actin and related sarcomeric proteins; they lack non-s-alpha-actinin, gamma-actin, and caldesmon; (g) in fibroblasts all alpha-actinin-containing structures are positive for the non-sarcomeric isoform, gamma-actin, and related non-sarcomeric proteins, including caldesmon; and (h) myocytes differ from all other types of adherent cultured cells in that they do not assemble authentic stress fibers; instead they assemble stress fiber-like structures of linearly aligned I-Z-I-like complexes consisting exclusively of sarcomeric proteins. |
| Databáze: | OpenAIRE |
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