JAC1, a member of the Hsp40/DnaJ family of proteins, encodes a specialized J-protein co-chaperone that assists Hsp70 in ironsulfur (Fe-S) cluster biogenesis [52, 53] . Fe-S clusters are among the most versatile protein co-factors in the cell and participate in electron transfer, ribosome biogenesis, regulating gene expression and enzyme activity, and nucleotide metabolism [54, 55, 56] . The inhibition of BMV replication upon dox-repressing P TET -JAC1 ( Fig. 3 and Table 5 ) may result from negatively affecting the activation and/or function of one or more cellular or viral factors required for BMV RNA replication. Previously, we showed that YDJ1, another J-protein co-chaperone of Hsp70 and Hsp90, is required to activate the BMV RNA replication complex, likely through modulating BMV 2a Pol folding or assembly into the complex [26] . Dox-repression of another heat shock protein, P TET -HSF1, inhibited BMV RNA replication by 84% (Fig. 3 and Table 5 ). Thus, our data suggest that BMV utilizes multiple members of the heat shock protein family to facilitate RNA replication.