ApcE plays an important role in light-induced excitation energy dissipation in the Synechocystis PCC6803 phycobilisomes.

Phycobilisomes (PBs) play an important role in cyanobacterial photosynthesis. They capture light and transfer excitation energy to the photosynthetic reaction centres. PBs are also central to some photoprotective and photoregulatory mechanisms that help sustain photosynthesis under non-optimal conditions.