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Imaging Subcellular Structures in the Living Zebrafish Embryo
Published on: April 2, 2016
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Profiling subcellular localization of nuclear-encoded mitochondrial gene products in zebrafish
Barbara Uszczynska-Ratajczak1,2, Sreedevi Sugunan3,4, Monika Kwiatkowska5,2,4
1Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland a.chacinska@imol.institute cwinata@iimcb.gov.pl buszczynska@ibch.poznan.pl.
Life Science Alliance
|October 25, 2022
Summary
Zebrafish mitochondrial fractions contain nuclear-encoded mRNAs, primarily those for large proteins. Proteostatic stress restricts these transcripts, favoring synthesis of larger, conserved proteins, unlike yeast localized translation.
Area of Science:
- Mitochondrial biology
- Molecular genetics
- Zebrafish model organism
Background:
- Mitochondrial proteins are mostly encoded by nuclear genes and synthesized in the cytosol.
- Understanding the spatial organization of these proteins is crucial for mitochondrial function.
Purpose of the Study:
- To characterize the spatial organization of nuclear-encoded mitochondrial gene products in zebrafish.
- To investigate the impact of mitochondrial protein import disorders on transcript localization.
Main Methods:
- RNA sequencing of different cellular fractions in zebrafish.
- Analysis of transcriptomic changes in response to the chchd4a mutation affecting mitochondrial protein import.
Main Results:
- Nuclear-encoded mRNAs are present in the mitochondrial fraction, particularly transcripts for large proteins.
- Proteostatic stress, induced by the chchd4a mutation, further restricts transcripts in the mitochondrial fraction.
- The largest and most evolutionarily conserved proteins are preferentially synthesized on the mitochondrial surface under stress.
- Nuclear-encoded mitochondrial transcripts translated by cytosolic ribosomes resist global translation shutdown.
Conclusions:
- Zebrafish exhibit specific transcript localization to mitochondria, influenced by protein size and evolutionary conservation.
- Proteostatic stress leads to a more restricted mitochondrial transcript population.
- Vertebrates likely do not rely on localized translation for mitochondrial protein synthesis under stress, differing from yeast.
