FIGURE 4.

Microarray screen for PRC-dependent, CCCP-inducible genes. A, the strategy for identifying genes that depend upon PRC for their CCCP inducibility is outlined. Lentiviral transductants having either normal PRC expression (control shRNA) or severely reduced PRC expression (PRC shRNA1) were either untreated (−) or treated (+) with CCCP for 16 h in quadruplicate plates. RNA was isolated and subjected to microarray analysis, and for each transductant the -fold CCCP induction was normalized to the untreated control. Of the subset of genes showing a differential response to CCCP between the two transductants, 45 genes had a response to CCCP that was at least 2-fold greater in the shRNA control than in the PRC shRNA1 transductant. The quantitative basis for selecting these genes is shown in Table 1. Of these 45 genes, 31 showed no significant induction by CCCP in the PRC shRNA1 transductant, consistent with complete PRC dependence. B, genes identified in the screen were assigned to the indicated functional categories. Underlined are 31 genes that show complete PRC dependence for their response to CCCP. The quantitative data are in Table 1.