# Structure, regulation, and evolution of the splicing machinery

> **NIH GM R35** · UNIVERSITY OF CALIFORNIA SANTA CRUZ · 2026 · $490,105

## Abstract

PROJECT SUMMARY
 The complexity of human splicing is daunting, yet intervention in splicing for treatment of diseases holds
huge potential. Based on strong preliminary results, we propose three areas of investigation that leverage our
group’s deep knowledge of splicing to address critical open questions, and to explore the potential for innovative
engineering. The first area addresses the mechanism by which U2 snRNP captures the intron branchpoint
early in spliceosome assembly, a step altered by recurrent cancer mutations and targeted in nature by
antibiotic-producing bacteria. Using new reporters in which two branchpoints compete for recognition, we have
identified a novel splicing fidelity mechanism we call “NO-BP decay,” in which U2 complexes that fail due to
aberrant branchpoint selection are destroyed. We will characterize this process, applying a battery of candidate
gene-based suppressor screens and biochemical tests in splicing extracts. The second area of investigation
addresses how splicing is integrated with transcription and cell growth at the individual gene and cellular
levels, an emerging area in need of innovation if splicing is to be successfully engineered. Preliminary results
indicate that yeast cells have a limited capacity for splicing that creates competition for pre-mRNAs that is critical
to cell function. We will measure both splicing capacity and the dynamics of competition, using RNA sequencing
to develop a predictive model that explains how splicing is coordinated at a systems level. To understand the
contribution of individual genes to this system we are applying synthetic biology approaches. We have
engineered site-specific pauses of RNA polymerase II and shown that they alter splicing efficiency and
alternative splicing, by unknown mechanism(s) that we will dissect. We will also explore in detail the role of
splicing noise (stochastic variations in splicing output over time) on the ability of splicing to control stable
homeostatic expre

## Key facts

- **NIH application ID:** 11323132
- **Project number:** 5R35GM145266-05
- **Recipient organization:** UNIVERSITY OF CALIFORNIA SANTA CRUZ
- **Principal Investigator:** Manuel  Ares
- **Activity code:** R35 (R01, R21, SBIR, etc.)
- **Funding institute:** GM
- **Fiscal year:** 2026
- **Award amount:** $490,105
- **Award type:** 5
- **Project period:** 2022-05-16T00:00:00 → 2027-04-30T00:00:00

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/11323132

## Citation

> US National Institutes of Health, RePORTER application 11323132, Structure, regulation, and evolution of the splicing machinery (5R35GM145266-05). Retrieved via AI Analytics 2026-07-02 from https://api.ai-analytics.org/grant/nih/11323132. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*