# Mechanistic Basis of Circadian Clocks in Bmal1 Knockout Mice

> **NIH NIH R01** · UNIVERSITY OF PENNSYLVANIA · 2022 · $473,094

## Abstract

PROJECT SUMMARY
Circadian clocks are believed to exist at almost all levels of life and play a fundamental role in
maintenance of physiological and behavioral processes in accordance with the day-night cycle. The
conventional model that describes the circadian clockwork at the molecular level revolves around
transcriptional/translational feedback loops (TTFLs). In these models, BMAL1 is believed to act as an
indispensable component of the timekeeping system. However, we have found pervasive molecular
oscillations in the transcriptome and proteome of Bmal1-/- mice. A research program will be undertaken
to obtain a comprehensive mechanistic understanding of these “non-canonical” circadian rhythms in
Bmal1-/- mice. The project will broadly focus on understanding transcriptional (Aim 1) and post-
transcriptional (Aim 2) functioning of cells and tissues from Bmal1-/- mice. (Aim1) Our preliminary data
suggest that the novel circadian rhythms we see might be underpinned by the recruitment of ETS family
transcription factors into the clockwork. We will functionally test their role by knocking out key ETS
proteins using CRISPR. We will also perform ChIP-seq experiments to find genomic targets driving
rhythmic transcripts that we see. In addition, we will perform nuclear proteomics to elucidate novel
transcription factors that might mediate rhythmic transcription. Furthermore, we will perform protein
interaction analyses using immunoprecipitation mass spectrometry to determine how ETS proteins and
redox proteins may physically interact. (Aim 2) We found redox oscillations in Bmal1 knockout cells,
implying that these play a role in the clockwork of Bmal1-/- mice. Consequently, we will investigate novel
redox oscillations in Bmal1 knockout cells using a novel redox proteomics workflow that we have
developed. In addition, we will characterize the rhythmic phospho-proteome and kinome of cells, which
we have found could be profoundly affected by deletion of Bmal1. Finally, we will determine whether
metabolic circadian oscillations occur in Bmal1 knockouts. Gaining new molecular insights into the
circadian clockwork will guide future therapeutic interventions to alleviate the disorders associated with
circadian disruption, which are highly prevalent in contemporary society.

## Key facts

- **NIH application ID:** 10399594
- **Project number:** 5R01GM139211-02
- **Recipient organization:** UNIVERSITY OF PENNSYLVANIA
- **Principal Investigator:** Akhilesh Basi Reddy
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $473,094
- **Award type:** 5
- **Project period:** 2021-05-01 → 2025-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10399594

## Citation

> US National Institutes of Health, RePORTER application 10399594, Mechanistic Basis of Circadian Clocks in Bmal1 Knockout Mice (5R01GM139211-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10399594. Licensed CC0.

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