“…For instance, it has been observed that geminiviruses use host factors, such as the proliferating cell nuclear agent, a DNA polymerase accessory factor, NAC domain protein (SINAC1), a transcription factor, and plant homologs of retinoblastoma protein, to reprogram the host's cell cycle to allow replication of their own genome (Gutierrez, 2000;Gutierrez et al, 2004;Rojas et al, 2005). Likewise, several host factors for Tomato bushy stunt virus, a tombusvirus, and Brome mosaic virus, a bromovirus, have been thoroughly investigated using yeast as an artificial host system (Janda and Ahlquist, 1993;Duggal and Hall, 1995;Ishikawa et al, 1997;Noueiry and Ahlquist, 2003;Panavas et al, 2005;Mas et al, 2006;Serviene et al, 2006).…”