# Spatiotemporal mechanisms controlling circadian rhythms

> **NIH NIH R35** · UNIVERSITY OF MICHIGAN AT ANN ARBOR · 2024 · $407,373

## Abstract

ABSTRACT
Circadian clocks are cell-autonomous timekeepers that generate ~24-hour oscillations in gene
expression and control rhythms in almost all aspects of our behavior and physiology, including sleep-
wake cycles, metabolism, and immunity. Almost every cell in the human body has a clock and
dysregulation of clocks have been implicated in many human pathologies such as diabetes, cancer, and
neurodegenerative diseases. Although past studies, primarily using genetic screens and biochemical
assays, have outlined the genetic basis of circadian rhythms, very little is known about how circadian
clocks are organized and regulated at the subcellular level in an intact organism. Using Drosophila clock
neurons as a model system, my lab has recently made the surprising discovery that clock neurons
possess a complex internal organization where clock proteins, genes, and mRNAs are strategically
localized to specific subcellular compartments so that cellular events can occur at the right time and the
right place. Specifically, we have discovered that clock proteins and genes are organized into nuclear
condensates at the nuclear periphery during the circadian repression phase to enable transcriptional co-
repression. More recently, our studies revealed that clock mRNAs and proteins are localized to the
perinuclear cytoplasmic region, which is vital for the post-transcriptional regulation of clock mRNAs and
for generating ~24-h circadian rhythms. My laboratory will build upon these discoveries to achieve a
mechanistic understanding of the spatiotemporal mechanisms that govern circadian rhythms by
developing novel tools as well as harnessing the power of high-resolution live imaging, genetics,
proteomics, functional genomics, and behavior assays. First, we will utilize a novel proximity labeling
approach that we developed for identifying interaction partners of Period, a core clock protein, over the
circadian cycle to gain a deeper understanding of circadian regulation at the molecular level. Second, we
will investigate circadian genome organization in clock neuron nuclei using both imaging and sequencing-
based methods and determine the underlying molecular mechanisms to understand the role of nuclear
architecture on circadian rhythms. Third, we will determine the mechanisms that govern the
spatiotemporal localization of cytosolic clock mRNAs and proteins to understand the organizing principles
of cytoplasmic clock complexes. These studies have the potential to not only transform our understanding
of how cells keep time at the molecular level in intact organisms, but will also provide new insights into
important, overarching biological questions relevant to gene regulation in many contexts, including
learning and memory, development, and disease. Using insights from this research our long-term goal is
to engineer novel therapeutic approaches for the treatment of diseases associated with dysregulated
clocks.

## Key facts

- **NIH application ID:** 10842068
- **Project number:** 2R35GM133737-06
- **Recipient organization:** UNIVERSITY OF MICHIGAN AT ANN ARBOR
- **Principal Investigator:** Swathi Yadlapalli
- **Activity code:** R35 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $407,373
- **Award type:** 2
- **Project period:** 2019-09-01 → 2029-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10842068

## Citation

> US National Institutes of Health, RePORTER application 10842068, Spatiotemporal mechanisms controlling circadian rhythms (2R35GM133737-06). Retrieved via AI Analytics 2026-06-01 from https://api.ai-analytics.org/grant/nih/10842068. Licensed CC0.

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