The bidirectional promoter of two genes for the mitochondrial translational apparatus in mouse is regulated by an array of CCAAT boxes interacting with the transcription factor NF-Y.
The genes for mitoribosomal protein S12 (Mrps12) and mitochondrial seryl-tRNA ligase (Sarsm and Sars2) are oppositely transcribed from a conserved promoter region of <200 bp in both human and mouse. Using a dual reporter vector we identified an array of 4 CCAAT box elements required for efficient transcription of the two genes in cultured mouse 3T3 cells, and for enforcing directionality in favour of Mrps12. Electrophoretic mobility shift assay (EMSA) and in vivo footprinting confirmed the importance of these promoter elements as sites of protein-binding, and EMSA supershift and chromatin immunoprecipitation (ChIP) assays identified NF-Y as the key transcription factor involved, revealing a common pattern of protein-DNA interactions in all tissues tested (liver, brain, heart, kidney and 3T3 cells). The inherently bidirectional activity of NF-Y makes it an especially suitable factor to govern promoters of this class, whose expression is linked to cell proliferation.
Zanotto
Ernesto
E
Institute of Medical Technology & Tampere University Hospital, FI-33014, University of Tampere, Finland.
Shah
Zahid H
ZH
Jacobs
Howard T
HT
D000818:Animals; D001665:Binding Sites; D023081:CCAAT-Binding Factor / Q000378:metabolism*; D021901:DNA, Intergenic / Q000737:chemistry; D024202:Electrophoretic Mobility Shift Assay; D005786:Gene Expression Regulation; D050259:Genes, Mitochondrial; D017930:Genes, Reporter; D051379:Mice; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000235:genetics* / Q000378:metabolism; D041681:NIH 3T3 Cells; D011401:Promoter Regions, Genetic; D014176:Protein Biosynthesis; D012269:Ribosomal Proteins / Q000235:genetics* / Q000378:metabolism; D012714:Serine-tRNA Ligase / Q000235:genetics* / Q000378:metabolism
D023081:CCAAT-Binding Factor; D021901:DNA, Intergenic; D024101:Mitochondrial Proteins; D012269:Ribosomal Proteins; C112310:mitochondrial ribosomal protein S12; D012714:Serine-tRNA Ligase