Fig. 2.

CrCO interacts with NF-Y isoforms to form a transcriptional complex that associates with the promoter regions of the photoprotective genes. a Confocal live-cell imaging of the complemented strains, crco-2/CrCO (labelled as CrCO) and nfyb-1/NFYB (labelled as NF-YB), to visualize the localization of CrCO and NF-YB fused with Venus–3xFLAG in C. reinhardtii cells. Scale bars, 5 µm. b GAL4-based yeast two-hybrid (Y2H) assays. CrCO was fused to the GAL4-activation domain (AD–CrCO), whose ability to form heterodimers was tested by cotransformation of the GAL4-binding domain fused with NF–YB or NF-YC (BD–NF-YB or BD–NF-YC). Autoactivation was tested using empty vectors (AD or BD). The cells were plated on permissive (+His) or selective (−His) media and grown at 30 °C for 40 h after being spotted on the plates. c Chromatin immunoprecipitation (ChIP)-PCR assay of CrCO and NF-YB. Agarose gel electrophoresis showing the strength of the association of CrCO or NF-YB with the promoter regions of the photoprotective genes under different light treatments. ChIP was performed using 2 × 10⁸ cells/mL of crco-2/CrCO (labelled as CrCO) or nfyb-1/NFYB (labelled as NF-YB) cells cross-linked with 0.35% (v/v) formaldehyde after a 1-h light treatment