DNA Binding Proteins and Their Roles in Controlling Tissue Specific Gene Expression and Responses to Second Messengers

摘要: Transcriptional control is extensively used by mammalian cells to modulate the level of gene expression in response various environmental, hormonal, developmental and nutritional signals. By modulating rate transcription genes, cell can adapt new requirements adverse environmental conditions. The turning on off specific genes allows change its phenotype, assume functions progress along pathway. While biosynthesis any RNA molecule includes several distinct steps such as initiation, elongation termination, almost all cases transcriptional occurs at initiation step. Like other eukaryotes, contain three different polymerases, usually abbreviated Pol I, II III. Each these polymerases assigned transcribe a class molecules: e.g. I responsible for coding 28S 18S ribosomal RNAs; transcribes protein III 5S RNA, tRNAs, small species nuclear RNAs (Hansen Sharp 1987; Heintz Roeder 1982; Manley 1983). We will limit our discussion II.