Dissociation Kinetics of the Focal Adhesion Protein Zyxin in Normal and Tumor Cells

SAMANIEGO ONOFRE, ELIZABETH ; PALACIOS, EVA A. R.; SIGAUT, LORENA ; PIETRASANTA, LÍA I.

Córdoba

Congreso; LI Reunión Anual de la Sociedad Argentina de Biofísica; 2023

Under normal physiological conditions, cells can detect, process, and translate mechanical information provided by their extracellular environment through structures known as focal adhesions. These focal adhesions are transient protein complexes that link the extracellular matrix to components of the cytoskeleton through membrane receptors of the integrin family. Zyxin is a focal adhesion protein that is recruited during the final stages of adhesion assembly and acts as a mechanotransducer to sense and relay mechanical signals to the cell. It is known that the dissociation rate (kOFF) of zyxin from the focal adhesion complex is altered by external mechanical forces [1] and it is correlated with the forces generated by the cells [2]. In this study, we characterized the dynamics of the adhesive protein zyxin in normal (MCF10A) and tumor cells (MCF7) of the human mammary epithelium, to investigate whether the dissociation kinetics of this protein is altered in the two cell lines. For this purpose, cells are transiently transfected to express zyxin fused to a fluorescent protein, and the dynamic of the protein is characterized using fluorescence recovery after photobleaching (FRAP). The fluorescence recovery curves were obtained, analyzed, and contrasted with the model proposed by Lele et al. (2004) [3], from which the kinetic dissociation constant (kOFF) and mobile fraction were obtained. Based on the results, the molecular parameters between both cell lines were compared.REFERENCES[1] Lele T., et al. (2006), J Cell Physiol. 207, 187?194.[2] Sigaut L., et al. (2021), PLoS ONE 16: e0251411.[3] Lele T., et al. (2004), Mechanics & Chemistry of Biosistems, 1(3): 181-190.