Shotgun proteomic analysis of the unicellular alga Ostreococcus tauri

► We are presenting a shotgun proteomic study of Ostreococcus tauri. ► We characterise its proteome at different times of the day and various concentrations of nitrogen supply. ► We perform a label-free quantitation, an 15 N metabolic labelling as well as a phosphopeptide enrichment study. ► Dynamin, kinesin + GBSSI are found to be up-regulated during the transition from day to dark. ► In low nitrogen supply conditions, proteins involved in nitrogen assimilation are down-regulated.