Sequence and characterisation of the Z gene encoding ring finger protein of the lymphocytic choriomeningitis virus MX strain

We have cloned and characterised a cDNA encoding Z protein of recently iden tified MX strain of lymphocytic choriomeningitis virus (LCMV) persistently infecting human MaTu cells. Deduced amino acid sequence of LCMV MX Z protei n showed 88.9% identity with that of the LCMV Armstrong (ARM) strain and 80 .9% identity with that of the LCMV Traub (TRA) strain. It contained conserv ed zinc-binding RING finger domain and C-terminal proline-rich region. Nort hern blot analysis of total RNA from MaTu cells revealed presence of abunda nt truncated forms of L RNA. Z protein-specific rabbit antibodies were prod uced to glutathione S-transferase (GST)-Z fusion protein expressed in E. co li and used for the detection of Z protein in MaTu cells. Western blot and immunofluorescence analyses detected relatively high levels of Z protein in dicating its role in maintenance of persistent LCMV.