Identification of Ligands for the Tau Exon 10 Splicing Regulatory Element RNA by Using Dynamic Combinatorial Chemistry

• Published in: Chemistry : a European journal Vol. 17; no. 6; pp. 1946 - 1953
• Main Authors: López-Senín, Paula, Gómez-Pinto, Irene, Grandas, Anna, Marchán, Vicente
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 07-02-2011; WILEY‐VCH Verlag; Wiley-VCH
• Subjects: acridine; Basal ganglia; Biochemistry; Bioquímica; C.D; Central nervous system diseases; Chromosomes, Human, Pair 17 - genetics; Circular Dichroism; Combinatorial chemistry; Combinatorial Chemistry Techniques - methods; Dementia - genetics; Exons; Fluorescence; Fluorometry - methods; Framycetin - chemistry; Frontotemporal dementia; Humans; Introns; Ligands; Molecular recognition; Movement disorders; Neamine; Neurodegenerative diseases; Parkinsonian Disorders - genetics; Protein structure; Química combinatòria; Reconeixement molecular; Regulatory sequences; RNA; RNA - chemistry; RNA - genetics; RNA ligands; RNA Precursors - genetics; RNA Precursors - metabolism; RNA Splicing; RNA structures; Secondary structure; Spectroscopy; Splicing; Tau protein; Tauopathies - genetics; template synthesis; Titration
• ISSN: 0947-6539; 1521-3765; 1521-3765
• DOI: 10.1002/chem.201002065

We describe the use of dynamic combinatorial chemistry (DCC) to identify ligands for the stem‐loop structure located at the exon 10‐5′‐intron junction of Tau pre‐mRNA, which is involved in the onset of several tauopathies including frontotemporal dementia with Parkinsonism linked to chromosome 17 (FTDP‐17). A series of ligands that combine the small aminoglycoside neamine and heteroaromatic moieties (azaquinolone and two acridines) have been identified by using DCC. These compounds effectively bind the stem‐loop RNA target (the concentration required for 50 % RNA response (EC50): 2–58 μM), as determined by fluorescence titration experiments. Importantly, most of them are able to stabilize both the wild‐type and the +3 and +14 mutated sequences associated with the development of FTDP‐17 without producing a significant change in the overall structure of the RNA (as analyzed by circular dichroism (CD) spectroscopy), which is a key factor for recognition by the splicing regulatory machinery. A good correlation has been found between the affinity of the ligands for the target and their ability to stabilize the RNA secondary structure.
In the loop: Dynamic combinatorial chemistry (DCC) has allowed the identification of several ligands that bind with high‐to‐medium affinity and stabilize the stem‐loop structure located at the exon 10‐5′‐intron junction of pre‐mRNA (see scheme), which is involved in the onset of several tauopathies. There is a good correlation between the ligand's affinity for the target and its stabilizing properties. These results enhance our knowledge of how to design more specific RNA ligands.