Abstract
Overexpression of elongation factor-1α (EF1α) mRNA has been correlated with increased metastatic potential in mammary adenocarcinoma; however, this relationship was not explored at the level of protein expression. As EF1α has been shown in other cell types to be a component of the actin cytoskeleton, a likely effector in metastasis, the actin binding activity of EF1α from metastatic and nonmetastatic rat breast tumors and cell lines was investigated. We have shown that EF1α protein is overexpressed in metastatic compared to nonmetastatic cells and whole tumors. Similarly to other EF1αs, both types of tumor EF1α bind to F-actin, but EF1α from metastatic cells has a reduced affinity for actin. In addition, there is a high correlation between the intracellular distribution of filamentous actin and EF1α in those cytoskeletal structures thought to be important for supporting the cellular motility required for metastasis. Following stimulation with EGF, there is a parallel increase in the amount of F-actin and EF1α associated with the cytoskeleton. The response to EGF can be blocked with cytochalasin D indicating that the binding of EF1α to the cytoskeleton is mediated by F-actin. We propose that a weakened association of EF1α with actin may be related to the metastatic process via an altered organization of the actin cytoskeleton and the differential translation of mRNAs associated with the cytoskeleton.
Original language | English (US) |
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Pages (from-to) | 2705-2714 |
Number of pages | 10 |
Journal | Journal of cell science |
Volume | 109 |
Issue number | 11 |
State | Published - Nov 1996 |
Keywords
- Cell motility
- Chemotaxis
- Cytoskeleton
- EGF
- Protein synthesis
ASJC Scopus subject areas
- Cell Biology