Effect of YXXM motif on viral replication of subgroup J avian leukosis virus

Abstract:

Abstract:［Objective］ It was reported that subgroup J avian leukosis virus strain NX0101 activates PI3K /Akt pathway during early infection in DF-1 cells． Whether there is YXXM motif in the amino acid sequence of NX0101 and the function of YXXM motif were studied．［Methods］ The presence of internal transmembrane domains in the envelope protein of NX0101 was analyzed by Tmpred． Point mutation was introduced to change the YXXM motif in the NX0101 strain to FXXA． The plasmid containing the full genome of NX0101 with mutation within the YXXM motif in pMD18-T vector was constructed and transfected into DF-1 cells． Viral replication levels of NX0101 strain and the mutation one were tested and compared by real-time PCR and ELISA． ［Results］ The amino acid sequence of NX0101 strain had one YXXM motif (amino acids 554－557) in the cytoplasmic tail of envelope protein． The mutated NX0101 strain (Y554F，M557A) was rescued by reverse genetics technique． Viral replication of the mutated NX0101 strain was significantly lower than that of NX0101 strain in the level of either RNA or protein synthesis．［Conclusion］ The results revealed that theYXXM motif was important for virus NX0101 replication in DF-1 cells．