# Mechanisms of Splicing and Retrotransposition

> **NIH NIH R01** · WEST VIRGINIA UNIVERSITY · 2020 · $319,200

## Abstract

PROJECT SUMMARY/ABSTRACT
Group II introns are mobile genetic elements that are the likely evolutionary ancestors of both the
spliceosome and retrotransposons. RNA splicing and genomic change caused by retrotransposition are
fundamental processes common to all eukaryotes. In this proposal, we will examine the mechanisms that
drive the function of group II introns, and extend our findings back to their eukaryotic counterparts. Group II
introns are comprised of a catalytic RNA core that binds to an intron-encoded protein (IEP) to form a
ribonucleoprotein (RNP) complex. Splicing proceeds through two competing reactions: hydrolysis or
branching. Introns with a minimal RNA architecture splice exclusively through hydrolysis; however, the
addition of the IEP switches the splicing reaction to the branching pathway. This results in the formation of
branched lariat RNPs capable of intron mobility. The overall goal of this application is to determine the
detailed molecular mechanisms of how intron RNPs form and how these RNPs spread introns to new
locations in DNA. This goal will be achieved by combining biochemical and structural biology approaches
through the execution of the following two aims. 1) Determine the biochemical mechanism and structural
basis for hydrolytic ribozyme activity and protein stimulated lariat-RNP formation. This will allow a detailed
comparison of the active sites of a pure RNA self-splicing intron, self-splicing intron RNP and the
spliceosomal RNP, providing the first insights into how the splicing machinery evolved from a pure ribozyme
to the protein-RNA molecular machine responsible for processing almost all mRNA transcripts in the human
transcriptome. 2) Determination of the biochemical mechanism and structural basis for intron mobility into
DNA. These experiments will provide systematic mechanistic insights into the interplay between the intron
and the IEP reverse transcriptase that complete the intron integration reaction into new DNA locations.

## Key facts

- **NIH application ID:** 9985959
- **Project number:** 5R01GM133857-02
- **Recipient organization:** WEST VIRGINIA UNIVERSITY
- **Principal Investigator:** Aaron Reigh Robart
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $319,200
- **Award type:** 5
- **Project period:** 2019-08-01 → 2024-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9985959

## Citation

> US National Institutes of Health, RePORTER application 9985959, Mechanisms of Splicing and Retrotransposition (5R01GM133857-02). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/9985959. Licensed CC0.

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