# Molecular Mechanisms of Organelle Formation in Bacteria

> **NIH NIH R35** · UNIVERSITY OF CALIFORNIA BERKELEY · 2024 · $433,350

## Abstract

Much like their eukaryotic counterparts, numerous bacterial species use lipid-bounded organelles to
execute essential, and at times toxic, biochemical reactions in a compartmentalized fashion. Despite
their prevalence and importance to the health and survival of many organisms, relatively little is
understood regarding the formation, function, and diversity of bacterial organelles. To advance the
mechanistic study of lipid-bounded bacterial organelles, my group has developed two distinct model
systems: magnetosomes of magnetotactic bacteria and the ferrosome compartments of diverse
anaerobic microbes. Magnetosomes are lipid-bilayer invaginations of the cell membrane with a unique
protein content, within which nanometer-sized iron-based magnetic crystals are produced. Individual
magnetosomes are arranged into a chain with the help of an actin-like cytoskeleton, thus allowing
magnetotactic bacteria to use geomagnetic fields as a simple guide for low oxygen environments. The
cell biological features of magnetosomes make them ideal for understanding the evolution and molecular
basis of organelle biogenesis and biomineralization in bacteria. The magnetic and physical properties of
magnetosomes make them attractive targets for the development of biomedical applications including
their use as contrast agents for magnetic resonance imaging, as drug delivery vehicles and as a medium
for hyperthermic killing of tumor cells. More recently, my group has discovered a novel iron-accumulating
lipid-bounded organelle named the ferrosome. Ferrosomes are formed through the action of a small
number of genes and are found in diverse bacteria including resident members of the gut microbiome
and opportunistic pathogens. The research program outlined in this proposal will leverage the expertise
and existing knowledge within my group to explore three general areas of magnetosome and ferrosome
biology. First, we will study the molecular components, biochemical activities, and cellular pathways that
define the cell biological characteristics of bacterial organelles. Our current focus is to understand the
mechanisms of membrane biogenesis, protein sorting, and subcellular arrangement for magnetosomes
and ferrosomes. Second, we are interested in the biochemical output and cellular function of
magnetosomes and ferrosomes. Using comprehensive genetic, chemical, and physiological assays we
aim to understand how these organelles are integrated into the essential functions of their host
organisms. Third, we look to exploit the natural diversity of magnetosome- and ferrosome-forming
organisms to understand the common and unique evolutionary paths of organelle formation in bacteria.
The combination of these approaches will shed light on the molecular blueprint and evolutionary diversity
of bacterial compartments. In the process, we hope to devise more rational paths for synthetic re-
engineering of magnetosomes and ferrosomes to deploy them more effectively in applied settings.

## Key facts

- **NIH application ID:** 10833599
- **Project number:** 5R35GM127114-07
- **Recipient organization:** UNIVERSITY OF CALIFORNIA BERKELEY
- **Principal Investigator:** Arash Komeili
- **Activity code:** R35 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $433,350
- **Award type:** 5
- **Project period:** 2018-05-01 → 2028-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10833599

## Citation

> US National Institutes of Health, RePORTER application 10833599, Molecular Mechanisms of Organelle Formation in Bacteria (5R35GM127114-07). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10833599. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*