# Project 6: RNA and DNA alkylation repair

> **NIH NIH P01** · UNIVERSITY OF CALIF-LAWRENC BERKELEY LAB · 2020 · $490,183

## Abstract

PROJECT 6 
PROJECT SUMMARY 
Alkylation therapy is used every day in the clinic but the absence of predictive mechanistic knowledge limits 
efforts to inform and advance its use. Project 6 seeks this foundational knowledge and targets ALKBH3 and 
ASCC alkylation repair proteins and complexes that have been linked to cancer malignancy. ALKBH3 is a direct 
damage reversal dealkylase that works on RNA and ssDNA, and ASCC is a multifunctional, heterotrimeric 
helicase (ASCC1, ASCC2, and ASCC3 subunits). It is not known why these two proteins are linked to cancer 
malignancy and what their cellular targets are. The central hypothesis for Project 6, based on recent findings by 
the Project 6 team, is that ALKBH3-ASCC-mediated alkylation repair of both DNA and RNA is critical for 
alkylation damage responses in some cancer cells. Project 6 will determine cellular targets of alkylating agents, 
how ASCC recruitment to alkylating agent-induced foci are coordinated with other DNA processes, and define 
informative and biologically-relevant structures and assemblies. To achieve this, Project 6 will take advantage of 
the resources available in the SBDR Program Project and will directly collaborate with Projects 1, 2, 3 and 5, 
plus with the SCB and EMB Cores, and provide thematic synergy with all Projects. 
The Project 6 team is led by Dr. Nima Mosammaparast (Washington University), who has made groundbreaking 
discoveries including the dependence of certain cancer cells on ALKBH3 and ASCC3, the first observation of 
alkylating agent-induced foci, and the determination that these foci are not associated with typical DNA break 
repair proteins but with elongating transcription complexes. Roopa Thapar (MD Anderson) will bring her RNA 
expertise and do NMR and biophysical analysis. Susan Tsutakawa (LBNL) will do Small Angle X-ray Scattering 
(SAXS) and crystallography. Yuan He, Project 1 collaborator, will do Cryo-Electron Microscopy (CryoEM). SBDR 
PI John Tainer will insure coordination with other Projects and Program goals. 
Overall Project 6 Aim 1 uses cell biology and biochemistry to identify functionally-relevant ASCC-ALKBH3 
assemblies and to test hypotheses on DNA and RNA repair activities and their intersection with other repair 
pathways in cells. Aim 2 employs structural biology (NMR, crystallography, SAXS, and CryoEM) and biophysics 
to characterize active sites and interfaces that inform mechanisms and enable mutational validations. With our 
preliminary data, robust assays, and systems for producing and characterizing ASCC proteins and complexes 
in cells and in vitro, we are poised to add RNA and DNA alkylation repair to SBDR4. We will define biology- 
driven structures, mechanisms, and separation-of-function mutations to paradigm shift alkylation cancer 
research and provide powerful tools to examine alkylating therapies in cancer. Our results will directly improve 
SBDR’s ability to inform cancer researchers about RNA and DNA alkylation respons...

## Key facts

- **NIH application ID:** 10038024
- **Project number:** 5P01CA092584-20
- **Recipient organization:** UNIVERSITY OF CALIF-LAWRENC BERKELEY LAB
- **Principal Investigator:** Nima Mosammaparast
- **Activity code:** P01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $490,183
- **Award type:** 5
- **Project period:** 2001-09-27 → 2021-09-20

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10038024

## Citation

> US National Institutes of Health, RePORTER application 10038024, Project 6: RNA and DNA alkylation repair (5P01CA092584-20). Retrieved via AI Analytics 2026-05-28 from https://api.ai-analytics.org/grant/nih/10038024. Licensed CC0.

---

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