EXAR mechanism (IMAGE) Max-Planck-Gesellschaft Caption Schematic of the EXAR mechanism in neurons. Under normal conditions (wild type), ELAV binds to the fne RNA and inhibits the mini-exon that encodes a signal for nuclear localization. In the absence of ELAV (Δelav mutant), FNE is activated to replace ELAV function. When both proteins are missing (ΔelavΔfne mutant), neurons lose all their unique 3'UTRs. Credit MPI of Immunobiology and Epigenetics, V. Hilgers Usage Restrictions Use of images is limited to editorial coverage of scientific topics relating to the activities of the Max Planck Society. Any kind of commercial use (including, in particular, the exploitation of images by means of sale or incorporation in image databases or image catalogues) as well as any promotional use/use for merchandise purposes, disclosure to third parties or granting of related rights to third parties is expressly not permitted. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.