Question

You coat a Petri dish with fibronectin and proteoglycan and culture cells on the dish. The cells adhere to the dish. You repeat the experiment but this time add RGD peptides to the culture dish as the cells are added. What happens?

1) Cells adhere normally to the dish
2) Cells shrink
3) Cells lyse immediately
4) Cells do not adhere to the dish

Answer 1

Adding RGD peptides to the culture dish with cells likely prevents cell adhesion, as the peptides compete with fibronectin for integrin binding sites.

Step-by-step explanation:

When the RGD peptides are added to the culture dish along with cells, these peptides compete with fibronectin for binding to the integrin receptors on the surface of the cells. Since RGD peptides mimic the site on fibronectin to which integrins normally bind, they can inhibit the attachment of cells to the fibronectin-coated surface by blocking the integrin binding sites. Therefore, the likely outcome of adding RGD peptides to the culture dish is that cells do not adhere to the dish.