Identification of RNA aptamer which specifically interacts with PtdIns(3)P

Biochem Biophys Res Commun. 2019 Sep 10;517(1):146-154. doi: 10.1016/j.bbrc.2019.07.034. Epub 2019 Jul 24.

Abstract

The phosphinositide PtdIns(3)P plays an important role in autophagy; however, the detailed mechanism of its activity remains unclear. Here, we used a Systematic Evolution of Ligands by EXponential enrichment (SELEX) screening approach to identify an RNA aptamer of 40 nucleotides that specifically recognizes and binds to intracellular lysosomal PtdIns(3)P. Binding occurs in a magnesium concentration- and pH-dependent manner, and consequently inhibits autophagy as determined by LC3II/I conversion, p62 degradation, formation of LC3 puncta, and lysosomal accumulation of Phafin2. These effects in turn inhibited lysosomal acidification, and the subsequent hydrolytic activity of cathepsin D following induction of autophagy. Given the essential role of PtdIns(3)P as a key targeting molecule for autophagy induction, identification of this novel PtdIns(3)P RNA aptamer provides new opportunities for investigating the biological functions and mechanisms of phosphoinositides.

Keywords: Autophagy; Lysosome; Molecular imaging; PI3K; Phosphoinositide; RNA aptamer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aptamers, Nucleotide / chemistry
  • Aptamers, Nucleotide / metabolism*
  • Aptamers, Nucleotide / pharmacology
  • Autophagy / drug effects
  • Base Sequence
  • Cell Line
  • Humans
  • Lysosomes / drug effects
  • Lysosomes / metabolism
  • Phosphatidylinositol Phosphates / metabolism*
  • SELEX Aptamer Technique
  • Vesicular Transport Proteins / metabolism

Substances

  • Aptamers, Nucleotide
  • PLEKHF2 protein, human
  • Phosphatidylinositol Phosphates
  • Vesicular Transport Proteins
  • phosphatidylinositol 3-phosphate