# Unraveling the mechanism of ER-­associated organelle constriction and division

> **NIH NIH R01** · UNIVERSITY OF COLORADO · 2020 · $250,335

## Abstract

SUMMARY
 The ER has an elaborate structure. It consists of a continuous network of
membrane sheets and tubules that spread like a spiderweb into every corner of the
cytoplasm. Structural domains of the ER have been attributed different functions. ER
sheets are studded with ribosomes and are the preferred location for the translation,
translocation, and folding of membrane and lumenal proteins. However, very little is
known about the function significance of ER tubules even though they account for at
least half of the surface area of the ER in most eukaryotic cells. My lab has
uncovered a surprising new function for ER tubules in regulating the biogenesis of
endosomes and mitochondria at membrane contact sites. We discovered that ER
membrane contact sites define the position where mitochondria and early and late
endosomes undergo constriction and then division (1, 2). On mitochondria, ER
contact is purposefully localized to the position of nucleoid segration, division
machinery recruitment, initial constriction, and through fission. On endosomes, ER
tubules are recruited to cargo sorting domains that constrict and undergo fission. Our
current research goals are to understand how ER contact sites are regulated and
purposefully positioned and to discover by what mechanism can ER contact drive the
constriction and fission of other organelles. These studies are novel and are aimed at
unraveling the factors, functions, and mechanism of ER-mediated organelle division.
1) Friedman JR, Lackner LL, West M, DiBenedetto JR, Nunnari J & Voeltz GK*
(2011). ER Tubules Mark Sites of Mitochondrial Division. Science 334: 358-362.
2) Rowland AA, Chitwood P, Phillips MJ & Voeltz GK* (2014) ER contact sites
 define the position and timing of endosome fission. Cell 159: 1027-41.

## Key facts

- **NIH application ID:** 9848597
- **Project number:** 5R01GM120998-04
- **Recipient organization:** UNIVERSITY OF COLORADO
- **Principal Investigator:** Gia Voeltz
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $250,335
- **Award type:** 5
- **Project period:** 2017-01-01 → 2021-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9848597

## Citation

> US National Institutes of Health, RePORTER application 9848597, Unraveling the mechanism of ER-­associated organelle constriction and division (5R01GM120998-04). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/9848597. Licensed CC0.

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