[Methods of studying transcriptional regulation of gene expression]

Transcription is the first step in the course of decoding the structural information of proteins in the genome into functional products. Transcriptional regulation is thus a universal mode of regulatory mechanism of gene expression. Methods of studying transcriptional regulation are diverse and main procedures to measure transcriptional activity and to characterize cis- and trans-acting elements are summarized. Studies on transcriptional regulation of the genes in the airway, including those of surfactant apoproteins and of Clara cell 10 kDa protein (CC10), have revealed the presence of trans-acting elements, which are the transcription factors found in other organ such as the liver and thyroid gland, suggesting a common regulatory mechanism for cell-type specific transcription in some organs and tissues. Such studies have also provided possible means to transfer genes, in a cell-type specific manner, for therapeutic purposes.