%0 Journal Article
%T Algal photoprotection is regulated by the E3 ligase CUL4¨CDDB1DET1
%J -
%D 2018
%R https://doi.org/10.1038/s41477-018-0332-5
%X Light is essential for photosynthesis, but the amounts of light that exceed an organism¡¯s assimilation capacity can cause serious damage1. Photosynthetic organisms minimize such potential harm through protection mechanisms collectively referred to as non-photochemical quenching2. One mechanism of non-photochemical quenching called energy-dependent quenching (qE quenching) is readily activated under high-light conditions and dissipates excess energy as heat. LIGHT-HARVESTING COMPLEX STRESS-RELATED PROTEINS 1 and 3 (LHCSR1 and LHCSR3) have been proposed to mediate qE quenching in the green alga Chlamydomonas reinhardtii when grown under high-light conditions3. LHCSR3 induction requires a blue-light photoreceptor, PHOTOTROPIN (PHOT)4, although the signal transduction pathway between PHOT and LHCSR3 is not yet clear. Here, we identify two phot suppressor loci involved in qE quenching: de-etiolated 1 (det1)5 and damaged DNA-binding 1 (ddb1)6. Using a yeast two-hybrid analysis and an inhibitor assay, we determined that these two genetic elements are part of a protein complex containing CULLIN 4 (CUL4). These findings suggest a photoprotective role for the putative E3 ubiquitin ligase CUL4¨CDDB1DET1 in unicellular photosynthetic organisms that may mediate blue-light signals to LHCSR1 and LHCSR3 gene expression
%U https://www.nature.com/articles/s41477-018-0332-5