ИСТИНА

Nuclear proteins play an important role during infection by human, animal and plant viruses. Coilin, a major structural component of subnuclear Cajal bodies, is one of such proteins. Preliminary results have demonstrated that coilin is a modulator of hordeivirus infection. Here we show that the recombinant coilin protein from Arabidopsis thaliana (Atcoilin) is able to interact in vitro with movement proteins encoded by the first gene of the triple gene block (TGB) TGBp1s of two hordeiviruses barley stripe mosaic virus (BSMV) and poa semilatent virus (PSLV) forming ribonucleoprotein complexes with viral RNAs for virus transport in plants [1]. Using a set of deletion and point mutants we have demonstrated that the sites of protein-protein interactions are located within the arginine/lysine-rich clusters of the intrinsically disordered N-terminal domains (NTD) of both viral TGBp1s. The Atcoilin binding site involved in the interaction with has been mapped within its central domain (IDD). This domain is also characterizedcharacterized as disordered one. Interestingly this site within the coilin IDD also contains a cluster of positively charged amino acids. According to the current concept, disordered regions of proteins possess a high potential for interactions with various macromolecular partners. A possible model for interactions between the viral proteins and cellular nuclear protein is discussed. This work was supported by the RFBR grant 13-04-01467.