# Human COX7B Contains a cAMP-Responsive Riboswitch that Modulates Oxidative Phosphorylation

> **NIH NIH F31** · UTAH STATE HIGHER EDUCATION SYSTEM--UNIVERSITY OF UTAH · 2024 · $39,593

## Abstract

PROJECT SUMMARY
 Riboswitches are regulatory RNA structures that control gene expression by binding to a small
molecule and changing conformation, allowing organisms to rapidly respond to changes in their metabolic
environments. They are prevalent in bacteria, but in over 20 years of study, only one eukaryotic riboswitch has
been found. It has long been postulated that there are more, but the lack of high-throughput screening assays
and in silico detection algorithms has limited discovery. To address these challenges, the Rutter lab has
developed a high-throughput approach combining dimethyl sulfate (DMS) structure probing and MIDAS (mass
spectrometry integrated with equilibrium dialysis for the discovery of allostery systematically) to screen for
novel eukaryotic riboswitches. A preliminary screen of HEK293 mRNA resulted in eight novel interactions in
the 5’UTR regions of various transcripts. The overarching objective of this proposal is to investigate the
regulatory abilities of these interactions and their downstream metabolic consequences in vivo. One of these,
COX7B, is a subunit of complex IV (CIV) in the electron transport chain (ETC) and bound to cyclic AMP
(cAMP) as a putative ligand. cAMP is known to stimulate respiration, but an obvious regulatory connection
between cAMP and COX7B is unknown. Other subunits of CIV are known to regulate respiration through
phosphorylation and substrate sensing, but COX7B’s function is yet to be defined. However, recent literature
places it at the interface of complex I (CI) and CIV in supercomplex formation. We propose that COX7B’s
5’UTR is a novel riboswitch that impacts respiration through regulating supercomplex formation. Aim 1
will investigate the binding event using isothermal titration calorimetry, DMS structure probing, and reporter
assays. Aim 2 will characterize COX7B’s role in CIV, testing for supercomplex formation, respiration, and CI
and CIII activity via blue-native PAGE (BN-PAGE), seahorse assays, and enzymatic assays in wild-type,
COX7B knock out (KO) and overexpression (OE) cell lines. Aim 3 will then define the metabolic impact of
COX7B mRNA interactions with cAMP in vivo. Mutations in the 5’UTR of COX7B will be introduced and
supercomplex formation, respiration, and complex activity in response to elevated cAMP levels will be
assessed as described. These data will highlight novel regulatory pathways for respiration and introduce a new
field of gene regulation to be explored. The Rutter Lab is the first to develop a high-throughput platform for
studying novel RNA-metabolite interactions and has a dedicated team devoted to studying novel riboswitches.
In addition, the University of Utah hosts a community of renowned scientists studying metabolism and RNA
biochemistry such as my sponsor, Dr. Jared Rutter, and co-sponsor, Dr. Ming Hammond. Finally, this project
contains a detailed training plan for developing multidisciplinary research and professional skills that will enable
me to becom...

## Key facts

- **NIH application ID:** 10827218
- **Project number:** 1F31GM153113-01
- **Recipient organization:** UTAH STATE HIGHER EDUCATION SYSTEM--UNIVERSITY OF UTAH
- **Principal Investigator:** Rachel Anne Skabelund
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $39,593
- **Award type:** 1
- **Project period:** 2024-07-01 → 2026-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10827218

## Citation

> US National Institutes of Health, RePORTER application 10827218, Human COX7B Contains a cAMP-Responsive Riboswitch that Modulates Oxidative Phosphorylation (1F31GM153113-01). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10827218. Licensed CC0.

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