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Updated: May 1, 2026
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Isolation of Physiologically Active Thylakoids and Their Use in Energy-Dependent Protein Transport Assays
Published on: September 28, 2018
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Derlin-like proteins are essential for the function of Euglena gracilis chloroplasts
Anežka Konupková1, Zoltán Füssy2, Priscila Peña-Diaz1
1Faculty of Science, Department of Parasitology, BIOCEV, Charles University, Vestec, Czech Republic.
Plant Physiology
|April 30, 2026
Summary
Two Euglena gracilis rhomboid pseudoproteases, DerL-1 and DerL-2, are essential for chloroplast protein import. Silencing them causes bleaching and loss of chloroplast structure, revealing a novel import mechanism.
Area of Science:
- Cell Biology
- Molecular Biology
- Biochemistry
Background:
- Euglena gracilis is a model organism for bioproduction research.
- Protein import into secondary chloroplasts is poorly understood.
- The origin of Euglena's secondary chloroplasts from a green alga presents unique biological questions.
Purpose of the Study:
- To investigate the function of Euglena gracilis rhomboid pseudoproteases DerL-1 and DerL-2.
- To elucidate the mechanism of protein import into Euglena's secondary chloroplasts.
- To understand the evolutionary context of protein import in algae.
Main Methods:
- RNA interference (RNAi) for gene silencing.
- Phenotypic analysis of silenced Euglena gracilis cultures.
- Chloroplast structure and protein expression analysis.
- Bioinformatic analysis of rhomboid pseudoprotease families.
Main Results:
- DerL-1 and DerL-2 are essential Euglena-specific rhomboid pseudoproteases.
- Silencing DerL-1/DerL-2 causes culture bleaching and growth delay.
- Loss of chloroplast structure and reduced photosynthetic protein expression observed.
- DerL-1/DerL-2 form a distinct subgroup unrelated to other eukaryotic rhomboid pseudoproteases.
Conclusions:
- DerL-1 and DerL-2 are crucial for chloroplast protein import in Euglena gracilis.
- These pseudoproteases likely form a translocon in the chloroplast envelope.
- This represents molecular convergence in plastid protein import mechanisms across different algal lineages.
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