Targeted disruption of A mitochondrial transcription factor a in the chicken DT40 cell lines

摘要

Mitochondrial transcription factor A (mtTFA) is a key regulator of mammalian mitochondrial DNA (mtDNA) transcription and replication. mtTFA is a nucleus-encoded high mobility group-box protein, which binds upstream of the light-and heavy-strand promoters of mtDNA and promotes transcription of mtDNA. We cloned and sequenced chicken mtTFA. The overall amino acid sequence of chicken mtTFA has 44% homology to human mtTFA. A chicken gene for mitochondrial transcription factor A was disrupted by gene targeting in the chichen B-cell line DT40 which has high level of homologous recombination and rapid growth rate. Heterozygous knockout DT40 cells exhibited about 50% reduction of mtDNA copy number. Similarly, the mitochondrial transcripts were reduced in the heterozygous knockout DT40 cells.