Transcriptional enhancer activity in the variable tandem repeat DNA sequence downstream of the human Ha-ras1 gene

Abstract A short term transfection technique using the chloramphenicol acetyltransferase gene as an assay system has been employed to examine the presence of transcriptional regulatory sequences within the variable tandem repeat (VTR) DNA sequence located downstream of the human Ha- ras 1 gene. Here we find that the VTR sequences possess an endogenous enhancer activity of both the normal and the T24 mutant Ha- ras 1 gene.