Discovering early light-induced phosphoproteins that respond to photoreceptor activation

ARICO DENISE; LUCIANA CASTRO; DIEGO WENGIER; MAZZELLA MA

Congreso; RAFV Reunion Argentina de Fisiologia Vegetal; 2018

Discovering early light-induced phosphoproteins that respond to photoreceptor activationDenise S. Arico, Luciana M. Castro, Diego L. Wengier, María Agustina Mazzella.Phosphorylation state of a protein is a key aspect that potentially governs its stability, activation, localization, activity and functionality. Several signaling pathways involve changes in phosphorylation as means of transducing effectively different stimuli. Among them, light triggers complex signaling networks that result in physiological and developmental responses. Phosphorylation?dephosphorylation events provide a powerful mechanism that links light perception to final response. We studied the early light-induced phosphoproteome in Arabidopsis thaliana through Label free LC-MS/MS proteomic approach. 41 phosphopeptides out of the 2267 identified, changed significantly their phosphorylation state in response to light. One phosphopeptide increased while 3 decreased their phosphor-isoforms in the presence of photoactivated photoreceptors. Currently, we are studying the phosphorylation dynamics, biological functions and cellular localization of two of these phosphoproteins which are potentially involved in early photomorphogenesis events. One is a transcription factor that interacts with COP1. The other is a negative regulator of SKD1 involved in endosomal trafficking of multivesicular bodies. Arabidopsis knock-out plants for its gene exhibit photomorphogenic response under red light. Here, we identified two early light induced phosphoproteins that reveal photoreceptors dependent phosphoregulation.