Cohen J B, Levinson A D
Department of Cell Genetics, Genentech Inc., South San Francisco, California 94080.
Nature. 1988 Jul 14;334(6178):119-24. doi: 10.1038/334119a0.
The T24/EJ allele of the Ha-ras proto-oncogene owes its powerful oncogenic activity not merely to the well documented mutation that perturbs the structure of the encoded polypeptide, but in addition to a second single nucleotide alteration in an intron that causes a tenfold increase in expression. This effect on expression is maintained upon transfer of the surrounding DNA to a heterologous gene, and as such defines a novel regulatory element.
Ha-ras原癌基因的T24/EJ等位基因其强大的致癌活性不仅归因于那个扰乱编码多肽结构的、有充分记录的突变，还归因于内含子中的另一个单核苷酸改变，该改变导致表达增加了十倍。当将周围的DNA转移到一个异源基因时，这种对表达的影响依然存在，因此定义了一种新的调控元件。
