Optochemical control of gene expression by photocaged guanine and riboswitches.

Optical control of biomolecules via engineered proteins or photoactive small molecules has had a profound impact on biology. However, optochemical tools to control RNA functions in living cells are relatively limited. We synthesized a photoactivatable (photocaged) guanine to modulate gene expression under riboswitch control in both mammalian cells and Escherichia coli by light.