Encodes a one helix protein homologous to cyanobacterial high-light inducible proteins. The protein is localized to the thylakoid membrane and its transcript is transiently induced by exposure to high light conditions. The mRNA is cell-to-cell mobile.
At5g02120 (OHP1) associates not only with the minimal reaction center complex of photosystem II but also with proteins involved in the assembly of its core components.