Fluorescence visualization of newly synthesized proteins in mammalian cells.
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Animals↗
Biomedical subjects
Julie C Liu
Publications and source records attributed to Julie C Liu.
Comparative cell response to artificial extracellular matrix proteins containing the RGD and CS5 cell-binding domains.
This study addresses endothelial cell adhesion and spreading on a family of artificial extracellular matrix (aECM) proteins designed for application in small-diameter vascular grafts. The aECM proteins contain domains derived from elastin and from fibronectin. aECM 1 contains the RGD sequence from the tenth type III domain of fibronectin; aECM 3 contains the fibronectin CS5 cell-binding domain. Negative control proteins aECM 2 and 4 are scrambled versions of aECM 1 and 3, respectively. Competitive peptide inhibition studies and comparisons of positive and negative control proteins confirm that adhesion of HUVECs to aECM proteins 1 and 3 is sequence specific. When subjected to a normal detachment force of 780 pN, 3-fold more HUVECs remained adherent to aECM 1 than to aECM 3. HUVECs also spread more rapidly on aECM 1 than on aECM 3. These results (i) indicate that cellular responses to aECM proteins can be modulated through choice of cell-binding domain and (ii) recommend the RGD sequence for applications that require rapid endothelial cell spreading and matrix adhesion.
Amino Acid Sequence↗
Cell-binding domain context affects cell behavior on engineered proteins.
A family of artificial extracellular matrix proteins developed for application in small-diameter vascular grafts is used to examine the importance of cell-binding domain context on cell adhesion and spreading. The engineered protein sequences are derived from the naturally occurring extracellular matrix proteins elastin and fibronectin. While each engineered protein contains identical CS5 cell-binding domain sequences, the lysine residues that serve as cross-linking sites are either (i) within the elastin cassettes or (ii) confined to the ends of the protein. Endothelial cells adhere specifically to the CS5 sequence in both of these proteins, but cell adhesion and spreading are more robust on proteins in which the lysine residues are confined to the terminal regions of the chain. These results may be due to altered protein conformations that affect either the accessibility of the CS5 sequence or its affinity for the alpha(4)beta(1) integrin receptor on the endothelial cell surface. Amino acid choice outside the cell-binding domain can thus have a significant impact on the behavior of cells cultured on artificial extracellular matrix proteins.
Amino Acid Sequence↗