Molecular Cloning and Analysis of the 5'-Flanking Region of the Human Thiamin Pyrophosphokinase Gene

We cloned and analyzed the 5'-flanking region of the human thiamin pyrophosphokinase gene (hTPK1). Truncation analysis using transiently transfected HepG2 cells revealed the minimal region required for basal activity of the hTPK1 promoter, which was encoded in a sequence between -105 and +441 relative to the transcription start site. In an electrophoretic mobility shift assay using the nuclear extracts from HepG2 cells and the synthetic oligonucleotide containing the Sp1 site, specific DNA-protein complexes were identified. These findings indicate the importance of the Sp1 cis-element in regulating the hTPK1 gene expression.