Two regulatory elements in the 5' region of the mouse mitochondrial malate dehydrogenase gene

We previously reported that the promoter region of the mouse mitochondrial malate dehydrogenase gene is located within the 160 base-pairs (bp) region upstream from the initiation codon, named P1, and that the -160/-131 bp region contains sequence(s) essential for the promoter activity of mitochondrial malate dehydrogenase gene. To define more precisely the regulatory mechanism of this gene, a 3' deletion analysis was performed using constructs with a constant 3' boundary at -130 bp. We obtained evidence of an additional positive regulatory element located between -393/-249 bp, named P2, the function of which can be separated from that of the P1. DNase I footprinting and gel-sift mobility experiments showed that nuclear protein binding to the P2 was not inhibited in the presence of the P1 sequences.