INCREASED CONCENTRATION OF SOME TRANSCRIPTION FACTOR-BINDING SITES INHUMAN RETROPOSONS OF THE ALU FAMILY

Eukaryotic gene expression is dependent on short protein-binding DNA s equence motifs promoting the assembly of multiprotein transcription co mplexes. Human retroposons of the Alu family are known to contain some high-affinity binding sites for transcription factors, which may serv e as signals in regulation of expression of RNA-polymerase II-transcri bed genes. In this computer study we have compared the density of ten consensus transcription factor binding sites in a set of human mature mRNA, human promotors and Alu repeats. Our results indicate that Alu r etroposons and promotor sequences have significantly higher mean densi ty of these sites compared to RNAs. It is suggested that the majority of Alu repeats do have the potential for regulating gene expression vi a modulation of RNA polymerase II-dependent transcription.