Abstract
The Dbl oncogene is the putative exchange factor for two small GTP-binding proteins, RhoA and CDC42 which are involved in the polymerization of actin to produce stress fibers and filopodia, respectively. We report here that Dbl oncogene-transformed NIH3T3 cells show actin stress fibers only when cells are plated on fibronectin. Plating of cells on collagen I and IV as well as on poly-D-lysine and gelatin induces polymerization of actin to form filopodia, lamellipodia and membrane ruffles but not stress fibers. The putative collagen receptors, α1/β1 and α2/β1 integrins are expressed at reduced level in Dbl-transformed cells compared to untransformed NIH3T3 fibroblasts. Nevertheless, adhesion to collagens is not altered. Inhibitory monoclonal antibody to mouse integrin β1 subunit blocked adhesion of both Dbl-transformed and untransformed NIH3T3 cells, demonstrating that adhesion to collagen I and IV is mediated by the β1 family of integrins. Dbl product rapidly induces the depolymerization of actin stress fibers, rounding up of the cells, and formation of filopodia and lamellipodia when microinjected in NIH3T3 cells plated on gelatin. Thus, Dbl may exert its effect on actin cytoskeleton organization in response to extracellular proteins by altering integrin-mediated signalling pathways.
| Original language | English |
|---|---|
| Pages (from-to) | 1933-1943 |
| Number of pages | 11 |
| Journal | Oncogene |
| Volume | 14 |
| Issue number | 16 |
| Publication status | Published - 1997 |
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Keywords
- Dbl
- Integrins
- Stress fibers
ASJC Scopus subject areas
- Cancer Research
- Genetics
- Molecular Biology
Cite this
Actin cytoskeleton polymerization in Dbl-transformed NIH3T3 fibroblasts is dependent on cell adhesion to specific extracellular matrix proteins. / Defilippi, Paola; Olivo, Cristina; Tarone, Guido; Mancini, Patrizia; Torrisi, Maria Rosaria; Eva, Alessandra.
In: Oncogene, Vol. 14, No. 16, 1997, p. 1933-1943.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Actin cytoskeleton polymerization in Dbl-transformed NIH3T3 fibroblasts is dependent on cell adhesion to specific extracellular matrix proteins
AU - Defilippi, Paola
AU - Olivo, Cristina
AU - Tarone, Guido
AU - Mancini, Patrizia
AU - Torrisi, Maria Rosaria
AU - Eva, Alessandra
PY - 1997
Y1 - 1997
N2 - The Dbl oncogene is the putative exchange factor for two small GTP-binding proteins, RhoA and CDC42 which are involved in the polymerization of actin to produce stress fibers and filopodia, respectively. We report here that Dbl oncogene-transformed NIH3T3 cells show actin stress fibers only when cells are plated on fibronectin. Plating of cells on collagen I and IV as well as on poly-D-lysine and gelatin induces polymerization of actin to form filopodia, lamellipodia and membrane ruffles but not stress fibers. The putative collagen receptors, α1/β1 and α2/β1 integrins are expressed at reduced level in Dbl-transformed cells compared to untransformed NIH3T3 fibroblasts. Nevertheless, adhesion to collagens is not altered. Inhibitory monoclonal antibody to mouse integrin β1 subunit blocked adhesion of both Dbl-transformed and untransformed NIH3T3 cells, demonstrating that adhesion to collagen I and IV is mediated by the β1 family of integrins. Dbl product rapidly induces the depolymerization of actin stress fibers, rounding up of the cells, and formation of filopodia and lamellipodia when microinjected in NIH3T3 cells plated on gelatin. Thus, Dbl may exert its effect on actin cytoskeleton organization in response to extracellular proteins by altering integrin-mediated signalling pathways.
AB - The Dbl oncogene is the putative exchange factor for two small GTP-binding proteins, RhoA and CDC42 which are involved in the polymerization of actin to produce stress fibers and filopodia, respectively. We report here that Dbl oncogene-transformed NIH3T3 cells show actin stress fibers only when cells are plated on fibronectin. Plating of cells on collagen I and IV as well as on poly-D-lysine and gelatin induces polymerization of actin to form filopodia, lamellipodia and membrane ruffles but not stress fibers. The putative collagen receptors, α1/β1 and α2/β1 integrins are expressed at reduced level in Dbl-transformed cells compared to untransformed NIH3T3 fibroblasts. Nevertheless, adhesion to collagens is not altered. Inhibitory monoclonal antibody to mouse integrin β1 subunit blocked adhesion of both Dbl-transformed and untransformed NIH3T3 cells, demonstrating that adhesion to collagen I and IV is mediated by the β1 family of integrins. Dbl product rapidly induces the depolymerization of actin stress fibers, rounding up of the cells, and formation of filopodia and lamellipodia when microinjected in NIH3T3 cells plated on gelatin. Thus, Dbl may exert its effect on actin cytoskeleton organization in response to extracellular proteins by altering integrin-mediated signalling pathways.
KW - Dbl
KW - Integrins
KW - Stress fibers
UR - http://www.scopus.com/inward/record.url?scp=0030929154&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0030929154&partnerID=8YFLogxK
M3 - Article
C2 - 9150360
AN - SCOPUS:0030929154
VL - 14
SP - 1933
EP - 1943
JO - Oncogene
JF - Oncogene
SN - 0950-9232
IS - 16
ER -