STUDY OF THE IN VIVO INTERACTION OF THE SILENCING SUPPRESSOR PROTEIN P0 OF POTATO LEAFROLL VIRUS (PLRV-AR) WITH HOST PROTEINS

BARRIOS-BARÓN, P;; DELFOSSE, V.C.; VANESA NAHIRÑAK,; ALMASIA, NATALIA INÉS; AGROFOGLIO, Y.C.; CECILIA VAZQUEZ ROVERE; DISTEFANO A.J

Congreso; : XXXII REUNIÓN ARGENTINA DE FISIOLOGÍA VEGETAL - XVI CONGRESO LATINOAMERICANO DE FISIOLOGÍA VEGETAL; 2018

Potato leafroll virus (PLRV) is one of the most damaging potato viruses and causes significant economic losses. This virus produces an important disease within all major potato cultivated regions. PLRV 5?-proximal ORF, ORF0, encodes P0 protein which is involved in symptom development and acts as a silencing suppressor protein. P0 proteins encoded by polerovirus members were shown to induce the degradation of the RNAi surveillance protein ARGONAUTE1.P0 mechanism of action depends on the interaction through an F-box like domain with members of the host SKP1-Cullin-F-box (SCF) family of E3-ubiquitin-ligases. Since this interaction varies among the different PLRV isolates, we study the in vivo interaction between P0 of the argentinian PLRV isolate (P0PL-Ar) and SKP1-like proteins of Arabidopsis (ASK1 and ASK2) and potato (StSKP1).We also analyze whether the conservation of P0 F-box domain is not only necessary for such interaction but also for the maintenance of its suppressor activity. We analyzed the interactions between wild type or mutated P0 versions and SKP1 proteins by yeast two-hybrid system. For the first time, we demonstrated that P0PL-Ar interacts with ASK1, ASK2 and StSKP1. In addition, these interactions, and P0PL-Ar suppressor activity are abolished by substitutions of essential residues in the F-box-domain