# Transcriptional Control of Hemoglobin Synthesis

> **NIH NIH R37** · UNIVERSITY OF WISCONSIN-MADISON · 2020 · $359,693

## Abstract

This application is to request a MERIT Award extension. Our progress validated our hypothesis that globin
gene expression and heme biosynthesis are interlinked through GATA-1-dependent mechanisms. Aim 1. To
distinguish between models for how heme amplifies GATA-1 activity to coordinate hemoglobin
biosynthesis and erythroid cell development/function. We will test whether heme permits or enhances
the GATA-1-dependent subnuclear transition that expels target loci from the nuclear periphery (Model 1) or
enhances GATA-1 activity subsequent to the transition (Model 2). If heme enhances the GATA-1-dependent
subnuclear transition of Bach1-sensitive genes, we will analyze the relationship between Bach1 and other
factors/coregulators that drive locus relocalization. As the relationship between subnuclear transitions and
chromatin looping remains elusive, we will determine whether heme and Bach1 regulate GATA-1-mediated
looping. If heme enhances activation subsequent to the transition, we will dissect late mechanistic steps.
Aim 2. To assemble activation and repression matrices and use these unique resources to elucidate
how the GATA-1/heme circuit establishes a critical sector of the erythroid cell transcriptome. We
hypothesize that GATA-1 target gene cohorts requiring unique ensembles of factors (including heme) and
coregulators share common mechanisms/pathways. We assembled first-gen. matrices illustrating
relationships between target gene expression and factor/coregulator requirements. Considerably expanded
second-gen. matrices will be developed. Unraveling the mechanisms/pathways will yield vital insights into
hemoglobin synthesis and erythroid cell development/function. Aim 3. To use a synthetic biology
approach involving cis-element engineering to ascertain how GATA-1-binding cis-elements control
heme biosynthesis and erythroid biology. Using CRISPR/Cas9, we will rewire the cis-element circuitry
controlling heme biosynthesis to determine why the Alas2 intron1 GATA-1-binding cis-element is much more
important than the intron8 GATA-1-binding cis-element. We will test the hypothesis that the difference
reflects intrinsic differences between the elements, or distinct flanking sequences render the elements
differentially active at endogenous loci. We will generate G1E-ER-GATA-1 cells in which the cis-elements
are swapped to determine if they retain or adopt new attributes at the ectopic chromosomal site. Concepts
will be validated in primary erythroblasts and in vivo. These studies will establish rules governing cis-element
function in erythroid cells, which will inform GATA factor-dependent mechanisms, biology, and pathologies.
RELEVANCE (See instructions):
The proposed studies shall provide fundamental insights into mechanisms underlying disorders of
hemoglobin synthesis, including thalassemias and anemias and diseases associated with aberrant heme
biosynthesis, including porphyrias. Moreover, the work shall provide a conceptual framework for the design...

## Key facts

- **NIH application ID:** 9995458
- **Project number:** 5R37DK050107-24
- **Recipient organization:** UNIVERSITY OF WISCONSIN-MADISON
- **Principal Investigator:** Emery H. Bresnick
- **Activity code:** R37 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $359,693
- **Award type:** 5
- **Project period:** 2016-08-15 → 2021-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9995458

## Citation

> US National Institutes of Health, RePORTER application 9995458, Transcriptional Control of Hemoglobin Synthesis (5R37DK050107-24). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/9995458. Licensed CC0.

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