Comprehensive identification of protein orthologs facilitated an understanding of the phylogenomics, protein conservation and phosphorylation of Ascoviridae species

Analysis of orthology is important for understanding protein conservation, function and phylogenomics. This study performed a comprehensive identification of Ascoviridae orthology based on identification of 366 ascoviridae protein homologue groups and phylogenetic analysis of 34 non-single copy proteins. Our fondings revealed 90 newly annotated proteins, five new identified Ascoviridae core proteins and 14 Ascovirus core proteins. Moreover, a phylogenomic tree of 11 ascoviridae species was inferred based on the concatenation of 35 of 45 Ascoviridae ortholog groups. In combination with phosphoproteomic results and conservation estimations, 30 conserved phosphorylation sites on 17 phosphoproteins were identified from a total of 176 phosphosites on 57 phosphoproteins from Heliothis virescens ascovirus 3h (HvAV-3h), supplying potential research targets for exploration of the detailed role of these protein in the regulation of viral infection mechanisms. This study would facilitates further Ascoviridae genome annotation and comparison and other functional genomic investigations.

Characterization of Heliothis Virescens Ascovirus 3h orf21 that Encodes a Virion Protein

Homologues of Heliothis virescens ascovirus 3h (HvAV-3h) orf21 are found in 9 completely sequenced members of the ascoviruses, but so far their functions are unknown. Here, orf21 (3h-21) was cloned in-frame into a pET-28a bacterial expression vector. The fusion protein produced by this construct was used for the preparation of a polyclonal antiserum. RT-PCR analysis showed a single transcript of 3h-21 of approximately 0.7kb was transcribed beginning at 24h post-infection in infected Helicoverpa armigera larvae. Western blot analysis of extracts from HvAv-3h-infected Helicoverpa armigera larvae detected a 25.6 kDa protein late in infection. This antiserum also reacted with a 25.6 kDa protein in purified virions of HvAv-3h. The protein was not extensively modified post-translation. Immunoelectron microscopy confirmed that the 3H-21 is associated with the structure of HvAV-3h virions.