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Interaction of focal adhesion kinase with cytoskeletal protein talin
H C Chen1, P A Appeddu, J T Parsons
1Department of Pathology, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA.
Abstract:
The interaction of cells with extracellular matrix proteins plays a critical role in a variety of biological processes. Recent studies suggest that cell-matrix interactions mediated by integrins can transduce biochemical signals to the cell interior that regulate cell proliferation and differentiation. These studies have placed the focal adhesion kinase (FAK), an intracellular protein tyrosine kinase, in a central position in integrin-initiated signal transduction pathways (Zachary, I., and Rozengurt, E. (1992) Cell 71, 891-894; Schaller, M., and Parsons, J. T. (1993) Trends Cell Biol. 3, 258-262). Here, we report data suggesting a possible association of FAK with the cytoskeletal protein talin in NIH 3T3 cells. We have identified a 48-amino acid sequence in the carboxyl-terminal domain of FAK necessary for talin binding in vitro. Furthermore, we have correlated the ability of integrin to induce FAK phosphorylation with its ability to bind talin using a mutant integrin lacking the carboxyl-terminal 13 amino acids. These studies suggest talin may be a mediator for FAK activation in signaling initiated by integrins and may provide an explanation for the dependence on the integrity of actin-cytoskeleton of multiple intracellular signaling pathways converging to FAK activation and autophosphorylation.
Insights
Cell-matrix interactions are vital for biological processes. This study suggests talin may mediate focal adhesion kinase (FAK) activation in integrin signaling, linking cytoskeletal integrity to intracellular pathways.
Area of Science:
- Cell biology
- Biochemistry
- Molecular signaling
Background:
- Cell-matrix interactions are crucial for biological processes.
- Integrin-mediated signaling regulates cell proliferation and differentiation.
- Focal adhesion kinase (FAK) is central to integrin-initiated signal transduction.
Purpose of the Study:
- To investigate the association between FAK and the cytoskeletal protein talin.
- To identify the FAK region responsible for talin binding.
- To explore talin's role in integrin-induced FAK activation.
Main Methods:
- Biochemical assays to detect FAK-talin association in NIH 3T3 cells.
- Identification of a specific 48-amino acid sequence in FAK for talin binding.
- Analysis of FAK phosphorylation using a mutant integrin lacking its carboxyl-terminal domain.
Main Results:
- A potential association between FAK and talin was identified.
- A 48-amino acid sequence in FAK's carboxyl-terminal domain is necessary for talin binding.
- Integrin-induced FAK phosphorylation correlates with talin binding, particularly in functional integrins.
Conclusions:
- Talin may act as a mediator in FAK activation during integrin signaling.
- This interaction could explain the dependency of FAK activation on actin-cytoskeleton integrity.
- Findings provide insights into the molecular mechanisms of cell-matrix communication.