Mussel adhesive protein fused with cell adhesion recognition motif triggers integrin-mediated adhesion and signaling for enhanced cell spreading, proliferation, and survival.

Adhesion of cells to a surface is a basic and important requirement in the fields of cell culture and tissue engineering. Previously, we constructed the cell adhesive, fp-151-RGD, by fusion of the hybrid mussel adhesive protein, fp-151, and GRGDSP peptide, one of the major cell adhesion recognition motifs; fp-151-RGD efficiently immobilized cells on coated culture surfaces with no protein and surface modifications, and apparently enhanced cell adhesion, proliferation, and spreading abilities. In the present study, we investigated the potential use of fp-151-RGD as a biomimetic extracellular matrix material at the molecular level by elucidating its substantial effects on integrin-mediated adhesion and signaling. Apoptosis derived from serum deprivation was significantly suppressed on the fp-151-RGD-coated surface, indicating that RGD-induced activation of integrin-mediated signaling triggers the pathway for cell survival. Analysis of the phosphorylation of focal adhesion kinase clearly demonstrated activation of focal adhesion kinase, a well-established indicator of integrin-mediated signaling, on the fp-151-RGD-coated surface, leading to significantly enhanced cell behaviors, including proliferation, spreading and survival, and consequently, more efficient cell culture.