FIGURE 2.

Expression of regulatory and structural genes required for the biogenesis of the mitochondrial respiratory apparatus. A, the expression of genes from the categories indicated below the x axis included those for nuclear transcription factors (PRC, NRF-1, NRF-2α, NRF-2β, and CREB), nucleus-encoded factors acting in mitochondria (Tfam, TFB1M, and TFB2M), and nucleus-encoded (COX4, COX17, SDHB, UQCRC2, and ATP5A1) and mitochondrion-encoded (COX2, ND6, and Cytb) respiratory subunits. Relative steady-state mRNA levels from the PRC shRNA1 and control shRNA transductants were normalized to 18 S rRNA as an internal control; values are expressed relative to the shRNA control, which was assigned a value of 1. Values are the averages ± S.E. for at least three separate determinations. B, dependence of the human COX17 promoter on NRF-1 recognition sites for both promoter activity and trans-activation by PRC. The 288-nucleotide proximal promoter from the human COX17 gene was cloned into a luciferase reporter plasmid, and the NRF-1 consensus sites were mutated either individually or in combination by site-directed mutagenesis as described under “Experimental Procedures.” Relative promoter activities were measured following transfection of U2OS cells either in the presence or absence of a PRC expression vector. C, the CCCP induction of genes listed under A was measured in both control shRNA (open bars) and PRC shRNA1 (closed bars) transductants. Values were normalized to 18 S rRNA as an internal control and expressed relative to untreated cells which were assigned a value of 1. A significant difference in CCCP induction between the two transductants is indicated by an asterisk denoting a p value of <0.05. Values are the averages ± S.E. for at least three separate determinations.