# Development of tools for site-directed analysis of gene function

> **NIH NIH R24** · IOWA STATE UNIVERSITY · 2020 · $31,160

## Abstract

The histone chaperone Rbbp4 is a component of multiple chromatin remodeling complexes
involved in cellular identity, plasticity, and reprogramming (Cheloufi and Hochedlinger, 2017;
Clemot et al., 2018; Conway et al., 2015). Rbbp4 also plays a significant role in cell cycle control
as a component of the MuvB complex that regulates cell cycle gene expression. Together with
transcription factors B-Myb and FoxM1, the MuvB complex controls the timing of gene
expression in G1/S (growth and DNA synthesis) and G2/M (mitosis) that allows progression
through the cell cycle (Fischer and Muller, 2017). We previously demonstrated in a zebrafish
model of rb1 defective embryonal brain tumors that rbbp4 is elevated more than 10-fold, and we
showed that in rbbp4 mutant embryos neural progenitors undergo tp53-dependent apoptosis
(Schultz et al., 2018). These results indicate inhibition of Rbbp4 may block the proliferation and
survival of brain cancer cells by activating cell cycle arrest through the Tp53 programmed cell
death pathway (Engeland, 2018). However, while most malignant human brain cancers show
elevated Rbbp4 expression (Schultz, Kool, McGrail unpublished results), many also harbor
inactivating mutations in Tp53. A deeper understanding of the mechanism by which Rbbp4
contributes to neural progenitor cell cycle progression may lead to new targets, that in
combination with Rbbp4 inhibitors, lead to brain tumor cell death. To address this, we propose
to apply our innovative CRISPR/Cas9 targeted integration strategy to generate novel proneural
cell cycle reporter and foxm1 conditional gene inactivation zebrafish lines. These will allow us to
examine how Rbbp4 and FoxM1 cooperate specifically in neural progenitor cell cycle
progression during brain development. The results will yield new insight into neural progenitor
cell cycle control and how its dysregulation drives unregulated proliferation of brain tumor cells.

## Key facts

- **NIH application ID:** 10185650
- **Project number:** 3R24OD020166-05S3
- **Recipient organization:** IOWA STATE UNIVERSITY
- **Principal Investigator:** KARL J CLARK
- **Activity code:** R24 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $31,160
- **Award type:** 3
- **Project period:** 2016-06-01 → 2024-02-29

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10185650

## Citation

> US National Institutes of Health, RePORTER application 10185650, Development of tools for site-directed analysis of gene function (3R24OD020166-05S3). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10185650. Licensed CC0.

---

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