title: Translational repression of the disintegrin and metalloprotease ADAM10 by a stable G-quadruplex secondary structure in its 5'-untranslated region.
abstract: Anti-amyloidogenic processing of the amyloid precursor protein APP by α-secretase prevents formation of the amyloid-β peptide, which accumulates in senile plaques of Alzheimer disease patients. α-Secretase belongs to the family of a disintegrin and metalloproteases (ADAMs), and ADAM10 is the primary candidate for this anti-amyloidogenic activity. We recently demonstrated that ADAM10 translation is repressed by its 5'-UTR and that in particular the first half of ADAM10 5'-UTR is responsible for translational repression. Here, we asked whether specific sequence motifs exist in the ADAM10 5'-UTR that are able to form complex secondary structures and thus potentially inhibit ADAM10 translation. Using circular dichroism spectroscopy, we demonstrate that a G-rich region between nucleotides 66 and 94 of the ADAM10 5'-UTR forms a highly stable, intramolecular, parallel G-quadruplex secondary structure under physiological conditions. Mutation of guanines in this sequence abrogates the formation of the G-quadruplex structure. Although the G-quadruplex structure efficiently inhibits translation of a luciferase reporter in in vitro translation assays and in living cells, inhibition of G-quadruplex formation fails to do so. Moreover, expression of ADAM10 was similarly repressed by the G-quadruplex. Mutation of the G-quadruplex motif results in a significant increase of ADAM10 levels and consequently APPsα secretion. Thus, we identified a critical RNA secondary structure within the 5'-UTR, which contributes to the translational repression of ADAM10.
authors: Adolf Butenandt Institute, Biochemistry, Ludwig Maximilians University, 80336 Munich, Germany. sven.lammich@med.uni-muenchen.de
authors: Sven
authors: S
authors: Lammich
authors: Frits
authors: F
authors: Kamp
authors: Judith
authors: J
authors: Wagner
authors: Brigitte
authors: B
authors: Nuscher
authors: Sonja
authors: S
authors: Zilow
authors: Ann-Katrin
authors: AK
authors: Ludwig
authors: Michael
authors: M
authors: Willem
authors: Christian
authors: C
authors: Haass
mesh_terms: D020121:5' Untranslated Regions / Q000502:physiology*; D051722:ADAM Proteins / Q000096:biosynthesis* / Q000235:genetics; D000072197:ADAM10 Protein; D053829:Amyloid Precursor Protein Secretases / Q000096:biosynthesis* / Q000235:genetics; D057809:HEK293 Cells; D006801:Humans; D008565:Membrane Proteins / Q000096:biosynthesis* / Q000235:genetics; D009154:Mutation; D009690:Nucleic Acid Conformation; D014176:Protein Biosynthesis / Q000502:physiology*
chemical_list: D020121:5' Untranslated Regions; D008565:Membrane Proteins; D053829:Amyloid Precursor Protein Secretases; D051722:ADAM Proteins; D000072197:ADAM10 Protein; C491236:ADAM10 protein, human