# Probing the spatiotemporal regulation of cell division

> **NIH NIH R01** · COLUMBIA UNIVERSITY HEALTH SCIENCES · 2020 · $316,918

## Abstract

PROJECT SUMMARY
In animal cells, cytokinesis is driven by constriction of an actomyosin contractile ring, which is positioned and
controlled by signaling from spindle microtubules. Cytokinesis requires a high degree of spatial and temporal
molecular regulation to ensure each daughter cell inherits a single nucleus. Although the essential molecular
players required for cytokinesis are known, many cytokinesis proteins localize dynamically to multiple
subcellular niches throughout cell division, potentially allowing multiple subcellular functions and making these
proteins difficult study using traditional genetic approaches. Optogenetics enable spatiotemporal studies by
locally targeting light to control protein function in specific subcellular regions. For this reason, we developed
FLIRT (Fast Local Infrared Thermogenetics), which uses an infrared (IR) laser to locally heat and thus locally
inactivate genetically-encoded fast-acting temperature sensitive (ts) mutant proteins with high spatiotemporal
precision. FLIRT is also reversible: the IR laser can be turned off at any point to stop local heating and allow
for protein reactivation. Furthermore, using FLIRT, non-ts-mutants (wildtype) can be used as controls for any
laser-induced damage induced by a given FLIRT procedure. In preliminary data using C. elegans embryos, we
calibrated the temperature induction achieved using FLIRT, validated the use of FLIRT on the subcellular level
in both the 1-cell embryo and the 16-cell embryo, and demonstrated that FLIRT can inhibit other cell biological
processes such as cell fate signaling in multicellular embryos and membrane partitioning in the adult gonad.
Having laid the foundation for further studies, we now propose experiments to define the spatiotemporal
regulation of actomyosin contractility and spindle microtubule-associated signaling complexes during
cytokinesis and address longstanding questions in the field, such as the relative contributions of equatorial vs.
polar actomyosin contractility during cell division. FLIRT experiments will also be conducted on cells in C.
elegans early embryos and in somatic cells with multicellular developing worm tissue. These experiments will
define the precise spatiotemporal regulation of key players in cytokinesis, test specific hypotheses regarding
their mechanisms of action, and test the universality of rules governing cytokinesis, whether the same
principles that apply to the early embryo also apply to somatic cells within a multicellular context.

## Key facts

- **NIH application ID:** 10019573
- **Project number:** 5R01GM130764-02
- **Recipient organization:** COLUMBIA UNIVERSITY HEALTH SCIENCES
- **Principal Investigator:** JULIE C CANMAN
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $316,918
- **Award type:** 5
- **Project period:** 2019-09-17 → 2023-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10019573

## Citation

> US National Institutes of Health, RePORTER application 10019573, Probing the spatiotemporal regulation of cell division (5R01GM130764-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10019573. Licensed CC0.

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