Discovery Of Novel Transcription Factors In HFL22W DbEST By Alignment Of Conserved Motif

Liver is an important organ in the metabolism of human. It has some important functions such as secreting bile, detoxification, phagocytosis and protection. The human fetal liver (HFL) during 22 weeks of gestation (HFL22W) is a major site of embryonic hematopoiesis, immune development, a source of hematopoietic stem cells, and it also has a lot of genes about cellular embedment, settlement and transposition.Transcription control is a committed step in eukaryotic gene expression. The mechanism is complex. Many transcription factors (TF) and genes are involved. There are about 2000-3000 transcription factors in human genome and only 95 known TFs existed in HFL. The unknown TFs in HFL may play some important roles in physiological process and the occurrence, development of some key diseases.The conserved structures in TF sequences and HFL22W EST sequences were studied by bioinformatic approaches to discover novel TFs.First the ORFs in cDNA sequences (contig HFL22W EST) were obtained and the ORFs were translated into amino sequences. Then the TF sequences from the TRANSFAC database were downloaded, and the database of TF conserved motifs was constructed according to the classification or family of TFs. Alignment was performed on the amino sequences and TF motifs. A regular expression of TF domains was also constructed and applied. A set of candidate amino sequences were obtained and further analyzed.The TF motifs in 6 classifications were studied. Finally, 13 candidate novel TFs with the motif of TFs in 4 classifications were discovered. The results obtained from the regular expression were consistent with that of analyzed using MEME software.