Synthetic peptides containing a conserved sequence motif of the Id protein family modulate vascular smooth muscle cell phenotype.

Modulation of smooth muscle cells to a proliferating and migrating phenotype with downregulated alpha-actin expression is observed upon vascular lesion formation. The Id proteins (inhibitors of cell differentiation) play a role in the development of this phenotype. In contrast, synthetic peptides based on a conserved 11-residue Id sequence trigger the switch to a contractile phenotype that shows reduced cell growth and migration, increased expression of alpha-actin and decreased Id protein levels.