The Z Protein of the New World Arenavirus Tacaribe Virus Has Bona Fide Budding Activity That Does Not Depend on Known Late Domain Motifs

The arenavirus small RING finger Z protein has been shown to be the main driving force of budding for several arenaviruses. This Z budding activity was found to be mediated by the late (L)-domain motifs P(T/S)AP and PPXY, located at the C terminus of Z. Here, we show that the Z protein of Tacaribe virus (TACV), a New World arenavirus, buds efficiently from cells despite lacking the canonical L-domain motifs P(T/S)AP and PPXY. Likewise, potential L-domain motifs ASAP and YLCL present in TACV Z did not exhibit any significant contribution to TACV Z budding activity. Budding of TACV Z was Tsg101 independent but required the activity of Vps4A/B. These results indicate that TACV Z utilizes a budding mechanism distinct from that reported for other arenaviruses.