Stabilization of adhesion plaques by the expression of drebrin A in fibroblasts.
The expression of drebrin A was induced in mouse fibroblasts (L cells) after transformation of cells with a vector that carried cDNA for rat drebrin A (developmentally regulated brain protein A) under the control of the promoter of the gene for metallothionein-I. When drebrin was expressed in the transformed cells (MTI-5 cells), the organization of actin filaments changed such that stress fibers were converted to a mesh-like structure. After subsequent treatment with 5 micrograms/ml cytochalasin D (a reagent that depolymerizes actin filaments), MTI-5 cells maintained their shape, while cells of a drebrin-negative cell line, MTI-11, formed retraction processes. Simultaneously, actin filaments changed into patchy dot-like aggregates in the cytoplasm of both MTI-5 and MTI-11 cells. These aggregates are known as cytoplasmic pools. In MTI-5 cells, adhesion plaques that were resistant to treatment with cytochalasin D appeared upon expression of drebrin. These adhesion plaques were immunostained with vinculin-specific antibodies, while those in MTI-11 cells were hardly immunostained. The amount of vinculin in MTI-5 cells increased in parallel with increase in the level of drebrin. These results suggest that expression of drebrin A induces changes in the assembly of actin filaments and adhesion plaques, with resultant modulation of cellular adhesion to the substratum.
Ikeda
K
K
Department of Physiology, Keio University, Tokyo, Japan.
Kaub
P A
PA
Asada
H
H
Uyemura
K
K
Toya
S
S
Shirao
T
T
D015153:Blotting, Western; D019187:Cadmium Compounds / Q000494:pharmacology; D002448:Cell Adhesion / Q000502:physiology; D015638:Cytochalasin D / Q000494:pharmacology; D018076:DNA, Complementary / Q000494:pharmacology; D005347:Fibroblasts / Q000737:chemistry / Q000166:cytology*; D006360:Heat-Shock Proteins / Q000187:drug effects; D006801:Humans; D007150:Immunohistochemistry; D007365:Intercellular Junctions / Q000737:chemistry; D009447:Neuroblastoma; D009479:Neuropeptides / Q000032:analysis* / Q000187:drug effects; D013431:Sulfates / Q000494:pharmacology; D014162:Transfection; D014407:Tumor Cells, Cultured / Q000502:physiology; D016596:Vinculin / Q000187:drug effects / Q000378:metabolism
D019187:Cadmium Compounds; D018076:DNA, Complementary; D006360:Heat-Shock Proteins; D009479:Neuropeptides; D013431:Sulfates; C053386:drebrins; D016596:Vinculin; D015638:Cytochalasin D; C037123:cadmium sulfate