Las proteínas virales p49 y pB602L son esenciales para la construcción de la cápsida icosaédrica del virus de la peste porcina africana

Abstract

African swine fever virus (ASFV), the only member of the AsfawiMae family. is one of the largest and more complex icosahedral virus which assemble in animal cells. The ASFV particle is approximately 200 nm in diameter and is composed of the DNAcontaining nucleoid surrounded by a thick protein layer denominated wre-shell, which is enwrapped by an internal envelope and the icosahedral capsid. We have approached the study of the viral morphogenesis by analyzing the effect of the repression of key viral proteins on this process. To this end. we have constructed and characterized two recombinant viruses which inducibly express protein p49 or protein pB602L. Protein p49 is a structural componen! of the viral particle. while protein pB602L has been proposed to function in the correct folding of the major capsid protein p72. Although p49 does not possess any canonical membrane insertion sequence, it associates with membranes during the infection, probably due to an interaction with a viral protein located in the internal envelope of the virus particle. It has been found that, in the absence of protein p49. the viral assembiy proms is altered wlh the generation of tubular structures of a large size and containing an aberrant capsid. On the other hand. the findings with the recombinant virus inducibly expressing protein pBBO2L show that, in the absence of the non-structural protein pB6021, aberrant "zipper-like" structures, which do not possess a capsid. are accumulated in the virus assembly sites. Under restrictive condiitions, protein p72 translocates from the virus factory to the cytoplasm, probabiy due to an inwrrect folding of the protein. The results obtained with the two inducible viruses indicate that protein p49 and protein pB602L are essential for the mrrect constniction of the virus icosahedral capsid.