Determination of isoform-specific RNA structure with nanopore long reads

Current methods for determening RNA structure with short-read sequencing cannot capture most differences between distinct transcript isoforms. Here, we present RNA structure analysis using nanopore sequencing (PORE-cupine),which combines structure probing using chemical modifications with direct long-read RNA sequencing and machine learning to detect secondary structures in cellular RNAs. PORE-cupine also captures global structural features, such as RNA binding protein (RBP) binding sites and reactivity differences at single nucleotide variants (SNVs). We show that shared sequences in different transcript isoforms of the same gene can fold into different structures, highlighting the importance of long-read sequencing for obtaining phase information. We also demonstrate that structural differences between transcript isoforms of the same gene lead to differences in translation efficiency. By revealing isoform-specific RNA structure, PORE-cupine will deepen our understanding of the role of structures in controlling gene regulation.