MitoCarta maps the eye-infecting amoeba's mitochondria in search of microbe-specific drug targets
MitoCarta mapped the genome and mitochondrial proteins of Acanthamoeba, the eye-infecting amoeba, across two of nine new papers. Its current drugs are untargeted and toxic, its lead author says, and a precise protein map is the first step toward better ones.
The Scientist · Science desk
What happened
- The Acanthamoeba work appears in the journals Cell and Cell Press Blue, part of a simultaneous release by the MitoCarta Tree of Life Consortium.
- MitoCarta had already mapped the mammalian mitochondrial proteome; this release extends the inventory to divergent branches of the tree of life.
- Acanthamoeba's genome was already sequenced, but the earlier gene annotation was only about 52 percent accurate, so the team rebuilt it first.
- To separate the genes, the team used long-read RNA sequencing, which reads transcripts of whole genes rather than short fragments stitched together afterward.
- The wider project is tracing mitochondrial proteins back to the last common ancestor of animals, plants, fungi and protists, which lived about 2 billion years ago.
Why it matters
- What's now possible capability Inventorying the proteins that run the amoeba's mitochondria gives drug developers a defined list of protein candidates to screen.
- What it limits constraint The amoeba seals itself in a drug-resistant cyst in the cornea, so a usable treatment has to hit a target that still matters in that hardened state.
- Who's exposed exposure The infection is already hard to diagnose and to treat, so patients bear the delay between a mapped target and a usable drug.
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Acanthamoeba lives almost everywhere, in water, soil and air, and most of the time it leaves people alone [2]. When it does infect, it can reach the eyes, the skin, even the brain [3]. "Our current drugs are untargeted and toxic, and we just need more options for treating these infections," said Jon Stefely, a metabolism investigator at the Morgridge Institute for Research and first author on the Acanthamoeba papers [6][5].
The design rule Stefely follows is specific: aim at biochemistry the amoeba does not share with its host. "A drug that targets a unique microbial protein or pathway is less likely to also harm the infected person," he said [10]. Finding those proteins meant going back to the nuclear genome, because that is where most mitochondrial proteins are encoded, not in the organelle's own small DNA [11]. An unannotated genome, Stefely said, is like "a page of words in a book" where "all the words were squished together and in a language that you don't know" [13].
So far, the work has produced a map. A proteome is an inventory of the proteins an organism uses; no safe compound that disables one of these proteins has been reported. The project was conceived by Vamsi Mootha of the Broad Institute and Harvard Medical School to trace mitochondrial proteins across living things [7]. That survey includes pathogens like Acanthamoeba [17].
What to watch
- Whether the papers name specific Acanthamoeba mitochondrial proteins with no human counterpart that could be screened as drug targets.
- Whether any candidate target still matters in the drug-resistant cyst form, the stage that defeats current treatment.
- Whether the consortium's other pathogen maps turn into actual drug programs.
Clarity's read
What the record supports and how the coverage leans. The claims behind it follow.
Reality
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- [1]
Stefely is first author of two new studies in the journals Cell and Cell Press Blue, among nine papers published concurrently by the MitoCarta Tree of Life Consortium.
- [2]
Acanthamoeba is a free-living, single-celled organism found in water, soil and air, and most of the time it does not harm humans.
- [3]
On rare occasions Acanthamoeba infects humans and can cause severe infections of the eyes, skin and brain.
- [4]
The eye infection, called Acanthamoeba keratitis, is difficult for doctors to diagnose and to treat.
- [5]
Jon Stefely is a metabolism investigator at the Morgridge Institute for Research and an assistant professor of biomolecular chemistry at the University of Wisconsin School of Medicine and Public Health.
- [6]
Our current drugs are untargeted and toxic, and we just need more options for treating these infections.
- [7]
The MitoCarta project was conceived by Vamsi Mootha, a molecular biologist at the Broad Institute, Massachusetts General Hospital, Harvard Medical School and the Howard Hughes Medical Institute.
- [8]
In the human cornea Acanthamoeba builds a thick, double-layered protective cell wall like those of plants, and in this cyst form it is hardy and resistant to currently available drugs.
- [9]
The team hoped that understanding the genes and proteins of mitochondrial function would reveal targets for highly specialized drugs that are not toxic to humans.
- [10]
A drug that targets a unique microbial protein or pathway is less likely to also harm the infected person.
- [11]
Although mitochondria have their own small DNA, most mitochondrial proteins are encoded in the cell nucleus.
- [12]
The amoeba's nuclear genome had been sequenced, but the prior annotation located genes with only about 52% accuracy, so the team improved it before targeting mitochondrial proteins.
- [13]
If you imagine a page of words in a book, it would be like all the words were squished together and in a language that you don't know.
- [14]
In the first paper the team used long-read RNA sequencing, which collects transcripts of entire genes rather than shorter snippets that must be pieced together later.
- [15]
The broader MitoCarta project is building an inventory of mitochondrial proteins across all branches of the tree of life to learn about the last common ancestor of animals, plants, fungi and protists, which lived about 2 billion years ago.
- [16]
MitoCarta had previously cataloged the mammalian mitochondrial proteome; the new papers add proteome inventories to divergent branches of the tree of life.
- [17]
The consortium deliberately selected pathogenic organisms such as Acanthamoeba for the survey, a strategy that could also lead to new drugs against those pathogens.
Sources
2 independent publishers whose own reporting we read for this story.
- genengnews.comProteomics Maps Eye-Infecting Acanthamoeba Mitochondria Across Oxygen Levels
1 article · October 1, 2026
- phys.orgEye-eating amoeba resists treatment—understanding its biochemistry could help
1 article · October 1, 2026
Topics and entities
Topics
- Acanthamoeba keratitis
- Antimicrobial drug target discovery
- Mitochondrial proteomics
Entities
- Acanthamoeba castellanii
- Broad Institute of MIT and Harvard
- Morgridge Institute for Research
- MitoCarta Tree of Life Consortium