Biochemical characterization of the RECQ4 protein, mutated in Rothmund-Thomson syndrome.

Rothmund-Thomson syndrome (RTS) is an autosomal recessive disorder characterized by growth deficiency, skin and skeletal abnormalities, and a predisposition to cancer. Mutations in the RECQ4 gene, one of five human homologs of the E. coli recQ gene, have been identified in a subset of RTS patients.

Transcription dependence of chromosomal gene targeting by triplex-forming oligonucleotides.

Triplex-forming oligonucleotides (TFOs) recognize and bind to specific DNA sequences and have been used to modify gene function in cells. To study factors that might influence triplex formation at chromosomal sites in mammalian cells, we developed a restriction protection assay to detect triplex-directed psoralen crosslinks in genomic DNA prepared from TFO-transfected cells. Using this assay, we detected binding of a G-rich TFO to a chromosomal site even in the absence of transcription when high concentrations of the TFO were used for transfection.