[Press release] Jumping genes have essential biological functions

From the 19 February 2015 EurekAlert!

“Alu” sequences are small repetitive elements representing about 10% of our genome. Because of their ability to move around the genome, these “jumping genes” are considered as real motors of evolution. However, they were considered for a long time as “junk” DNA, because, although they are transcribed into RNA, they encode no proteins and do not seem to participate actively in the cell’s functions. Now, the group of Katharina Strub, professor at the Faculty of Science of the University of Geneva (UNIGE), Switzerland, has uncovered two key functions of Alu RNAs in human cells, which are the subject of two different articles published in Nucleic Acids Research. Alu RNA can bind to specific proteins forming a complex called Alu RNP. On the one hand, this complex allows the cells to adapt to stress caused for example by chemical poisoning or viral infection. On the other hand, the same complex plays a role in protein synthesis by regulating the number of active ribosomes, suggesting that it could be part of the innate system of cellular defense against certain viruses.