# Hematopoietic Regulation via GATA Switches

> **NIH NIH R01** · UNIVERSITY OF WISCONSIN-MADISON · 2020 · $340,434

## Abstract

   
DESCRIPTION (provided by applicant): The advent of genomic technologies has yielded abundant datasets documenting protein-chromatin interactions genome-wide. Translating genomic data into physiological mechanisms remains extremely challenging. The prior funding period built upon our foundation of a defined cohort of GATA-1/GATA-2 binding sites discovered via ChIP-seq and their functional attributes. Since GATA-1 replaces GATA-2 at these sites upon erythropoiesis, which often alters transcription, we designated these "GATA switch sites". We developed evidence for an extremely innovative scenario in which two GATA switch sites at a locus (Gata2), both essential for embryogenesis, non-redundantly control distinct aspects of hematopoiesis - hematopoietic stem cell (HSC) generation from hemogenic endothelial cells (+9.5 site) or myeloid progenitor function (-77 site). This is the only example we are aware of in which two cis-elements at a locus exert essential, but distinct, functions in a multi-tiered developmental hierarchy and the only example of a cis-element required to generate a stem cell. As +9.5 and -77 alterations underlie non-malignant and malignant hematopoietic pathologies, the studies extend beyond understanding how master regulators establish/maintain genetic networks and how genetic/epigenetic mechanisms underlie stem/progenitor cell generation and function. Aim 1: To elucidate how a single cis-element controls HSC generation. We hypothesize that the multimeric complex on the +9.5 composite element in hemogenic endothelium ensures GATA-2 levels to establish/maintain a genetic network that promotes hematopoiesis. We will test models to explain how GATA-2 expression in +9.5-/- AGM stimulates HSC genesis. We will test whether signals targeting GATA-2 control HSC genesis in a +9.5- dependent manner and will use CRISPR/Cas9 to dissect how +9.5 regulates Gata2. Aim 2: To determine how two GATA switch sites at the same locus control distinct sectors in the hematopoietic hierarchy. +9.5 and -77 functions differ considerably. Hematopoietic clusters emerge from -77-/-, but not +9.5-/-, Aorta Gonad Mesonephros (AGM), consistent with a unique +9.5 role in HSC genesis. We will test the hypothesis that the two cis-elements use different mechanisms to control distinct components of hematopoiesis. Aim 3: To leverage rules governing +9.5 site function to discover novel regulators of hematopoiesis. Prioritization of 798 "+9.5-like" composite elements revealed a site that controls an unstudied gene encoding Sterile Alpha Motif protein 14. As Samd14 harbors a functional +9.5-like site, is expressed in hematopoietic stem/progenitor cells, has attributes distinct from known regulators of hematopoiesis, its downregulation reduces myeloerythroid progenitors, and we linked its function to that of Stem Cell Factor-c-Kit, we hypothesize that Samd14 is an important regulator of hematopoiesis. We will test models to explain how Samd14 regulates c-Kit signalin...

## Key facts

- **NIH application ID:** 9889100
- **Project number:** 5R01DK068634-15
- **Recipient organization:** UNIVERSITY OF WISCONSIN-MADISON
- **Principal Investigator:** Emery H. Bresnick
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $340,434
- **Award type:** 5
- **Project period:** 2004-07-01 → 2021-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9889100

## Citation

> US National Institutes of Health, RePORTER application 9889100, Hematopoietic Regulation via GATA Switches (5R01DK068634-15). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9889100. Licensed CC0.

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