Selection of bifunctional RNAs with specificity for arginine and lipid membranes

Here, we constructed a bifunctional RNA 10Arg aptamer that is specific for arginine and lipids. The selection-amplification method yielded several RNA 10Arg(D) sequences with improved affinity for arginine and liposomes. Generation of these bispecific RNAs supports the hypothesis that an RNA molecule can bind both to RNA-binding proteins through arginine and to membrane lipid rafts, thus facilitating RNA loading into extracellular vesicles. The molecular mechanisms of selective RNA loading into exosomes and other extracellular vesicles are not yet completely understood. In order to show that a pool of RNA sequences binds both the amino acid arginine and lipid membranes, we constructed a bifunctional RNA 10Arg aptamer specific for arginine and lipid vesicles. The preference of RNA 10Arg for lipid rafts was visualized and confirmed using FRET microscopy in neuroblastoma cells. The selection-amplification (SELEX) method using a doped (with the other three nucleotides) pool of RNA 10Arg sequences yielded several RNA 10Arg(D) sequences, and the affinities of these RNAs both to arginine and liposomes are improved in comparison to pre-doped RNA. Generation of these bispecific aptamers supports the hypothesis that an RNA molecule can bind both to RNA-binding proteins (RBPs) through arginine within the RBP-binding site and to membrane lipid rafts, thus facilitating RNA loading into exosomes and other extracellular vesicles.
Source: FEBS Letters - Category: Biochemistry Authors: Tags: Research Article Source Type: research