cAMP upregulates the transposable element mys-1: a possible link between signaling and mobile DNA.

Mys represents one of the many families of transposable elements abundant in the mammalian genome. Transposable elements (transposons, retrotransposons, Tr) are best described as "mobile DNA". Mechanisms for the transposition process have been well-described and recently two human Tr have been identified as the progenitors of disease producing insertions. A functional role, however, has never been proposed. Studying overexpression of genes induced by cAMP using the technique of subtractive hybridization, a clone Sch. p15 was isolated and sequenced. Computer assisted analysis of the sequence revealed strong homology to mys-1. In a parallel clone cAMP related and cAMP inducible genes were found by this technique. The fact that a mammalian Tr is modulated by the cell's signalling / second messenger system made us hypothesize that transposition may well be under physiological control and that Tr may play physiological roles as e.g. rearranging, reshuffling or programmed erasing of genes. Although methodologically sound, the interpretation of our data remains hypothetical due to the absence of any previous studies on transposition function in eukaryotes.