Differential Evolution of Antiretroviral Restriction Factors in Pteropid Bats as Revealed by APOBEC3 Gene Complexity

Hayward, Joshua A; Tachedjian, Mary; Cui, Jie; Cheng, Adam Z; Johnson, Adam; Baker, Michelle L; Harris, Reuben S; Wang, Lin-Fa; Tachedjian, Gilda

In addition to the expected A3Z1, A3Z2, and A3Z3 subtypes, several A3 amino acid sequences contained Z-domains distinct from the canonical domains as defined by a specific combination of key conserved residues (LaRue et al. 2009 ). This group, designated A3Z2B, carried both the A3Z2 domain-specific tryptophan-phenylalanine (WF) residues and the A3Z1 domain-specific arginine-adjacent isoleucine (RI) motif ( fig. 1A ). Of the 20 unique transcripts, 19 harbored a single Z-domain and one contained two Z-domains, an Nterminal A3Z2B domain paired with a C-terminal A3Z3 domain. These results indicate that pteropid bats express a more diverse repertoire of A3 mRNA than reported to date for other mammals ( fig. 1C ).