One possible reason for altered RNA replication is deregulation of viral protein accumulation. To test this, accumulation of BMV RNA replication proteins 1a and 2a Pol were assayed by Western blotting. Addition of dox to growth medium had no detectable effect on BMV 1a and 2a Pol accumulation in the wild type strain (Figs. 4 and 5) . For 20 of 24 confirmed hits, BMV 1a levels in doxtreated strains were comparable to their untreated sample (Figs. 4 and 5). However, in P TET -ADE13, P TET -DED1, P TET -PRE1 and P TET -RPT6 dox-treated cells there was a detectable increase in 1a compared to the untreated strains (Figs. 4 and 5) . Moreover, BMV 2a Pol levels were significantly increased in P TET -HSF1, P TET -PRE1 and P TET -RPT6 dox-treated strains (Fig. 5) . In P TET -JAC1 doxtreated cells, 2a Pol levels were elevated in the absence of dox, but reduced to near wild type levels in the presence of dox (Fig. 5) . These results suggest that, with the potential exception of HSF1, PRE1 and RPT6, viral protein regulation is unlikely to be the cause of altered viral RNA replication phenotypes upon depleting the products of the implicated genes.