Binding patterns of RNA-binding proteins to repeat-derived RNA sequences reveal putative functional RNA elements.

Area of Science:

• Genomics
• Molecular Biology
• RNA Biology

Background:

• Repeat-derived sequences in introns and long noncoding RNAs (lncRNAs) are recognized by RNA-binding proteins (RBPs).
• These repeat sequences are implicated in crucial biological processes like RNA splicing and transcriptional regulation.
• The full functional repertoire of repeat-derived RNAs remains incompletely characterized.

Purpose of the Study:

• To identify and characterize functional repeat-derived RNA elements.
• To analyze RNA-binding protein (RBP) binding patterns on repeat sequences using ENCODE eCLIP data.
• To predict novel functional RNA elements within transposable elements (TEs).

Main Methods:

• Analysis of ENCODE enhanced CLIP (eCLIP) data to map RBP binding sites.
• Quantification of RBP enrichment on repeat sequences in K562 and HepG2 cells.
• Prediction of functional RNA elements on LINE1 sequences and other TE fragments.

Main Results:

• Significant enrichment of eCLIP reads on repeat sequences was observed (10.75% in K562, 7.04% in HepG2).
• Functional RNA elements were predicted on both sense and antisense strands of long interspersed element 1 (LINE1) sequences.
• New sets of RBPs were identified on fragments from various transposable element (TE) families, some exhibiting stable secondary structures and integration into introns or lncRNAs.

Conclusions:

• Repeat-derived RNA sequences are significant functional elements within endogenous noncoding RNAs.
• These findings expand our understanding of the roles of repetitive elements in gene regulation.
• The study highlights the potential of repeat-derived RNAs as key components in cellular RNA processing and function.