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Research Database PMU-SQQUID

Conventional protein kinase C mediates phorbol-dibutyrate-induced cytoskeletal remodeling in a7r5 smooth muscle cells.
Hai, CM; Hahne, P; Harrington, EO; Gimona, M;
Exp Cell Res. 2002; 280(1): 64-74.
Originalarbeiten (Zeitschrift)

PMU-Authors

Gimona Mario

Abstract

Phorbol dibutyrate (PDBu) induced the formation of podosome-like structures together with partial disassembly of actin stress fibers in A7r5 smooth muscle cells. These podosomes contained alpha-actinin, F-actin, and vinculin and exhibit a tubular, column-like structure arising perpendicularly from the bottom of PDBu-treated cells. The conventional protein kinase C (PKC) antagonist, GO6976, inhibited PDBu-induced cytoskeletal remodeling at 0.1 muM, whereas the novel PKC antagonist, rottlerin, was ineffective at 10 muM. PDBu induced the translocation of the conventional PKC-alpha but not the novel PKC-delta to the sites of podosome formation in A7r5 cells. Although partial disassembly of actin stress fibers was observed in both Y-27632- and PDBu-treated cells, focal adhesions were much reduced in number and size only in Y-27632-treated cells. Furthermore, PDBu restored focal adhesions in Y-27632-treated cells. Live video fluorescence microscopy of alpha-actinin GFP revealed a lag phase of about 20 min prior to the rapid formation and dynamic reorganization of podosomes during PDBu treatment. These findings suggest that conventional PKCs mediate PDBu-induced formation of dynamic podosome-like structures in A7r5 cells, and Rho-kinase is unlikely to be the underlying mechanism. The podosome columns could represent molecular scaffolds where PKC-alpha phosphorylates regulatory proteins necessary for Ca2+ sensitization in smooth muscle cells. (C) 2002 Elsevier Science (USA).


Useful keywords (using NLM MeSH Indexing)

Acetophenones/pharmacology

Actinin/metabolism

Actins/metabolism

Amides/pharmacology

Animals

Benzopyrans/pharmacology

Carbazoles/pharmacology

Cells, Cultured

Cytoskeleton/drug effects

Cytoskeleton/physiology

Cytoskeleton/ultrastructure*

Enzyme Inhibitors/pharmacology

Green Fluorescent Proteins

Indoles/pharmacology

Isoenzymes/metabolism

Luminescent Proteins/metabolism

Muscle, Smooth, Vascular/drug effects

Muscle, Smooth, Vascular/physiology

Muscle, Smooth, Vascular/ultrastructure*

Phorbol 12,13-Dibutyrate/pharmacology*

Protein Kinase C/antagonists*

inhibitors

Protein Kinase C/metabolism

Protein Kinase C/physiology*

Protein Kinase C-alpha

Protein Kinase C-delta

Protein Transport/drug effects

Pyridines/pharmacology

Rats

Recombinant Fusion Proteins/metabolism

Transfection

Vinculin/metabolism