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Updated: May 15, 2026
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Mitochondrial Transformation in Baker's Yeast to Study Translation and Respiratory Complex Assembly
Published on: June 7, 2024
Alternative translation initiation augments the human mitochondrial proteome
Lawrence Kazak1, Aurelio Reyes, Anna L Duncan
1MRC-Mitochondrial Biology Unit, Wellcome Trust-MRC Building, Cambridge CB2 0XY, UK.
Nucleic Acids Research
|January 1, 2013
Summary
Alternative translation initiation (ATI) produces multiple proteins from one transcript. A new method, downstream ATI (dATI), reveals cryptic mitochondrial signals, expanding the mitochondrial proteome.
Area of Science:
- Molecular Biology
- Cell Biology
- Genomics
Background:
- Alternative translation initiation (ATI) allows a single transcript to generate multiple proteins.
- Protein trafficking to cellular compartments, including mitochondria, can be regulated by ATI.
- The mitochondrial proteome is incompletely understood.
Purpose of the Study:
- To identify proteins targeted to mitochondria via a novel ATI mechanism.
- To computationally predict and experimentally validate downstream ATI (dATI) in mammals.
- To expand the known human mitochondrial proteome.
Main Methods:
- Genome-wide computational screening to predict cryptic mitochondrial targeting signals.
- Experimental validation using immunoblotting and immunocytochemistry.
- Cellular localization studies, co-immunoprecipitation, and assessment of protein abundance under mitochondrial DNA/RNA depletion.
Main Results:
- A computational screen predicted dATI signals for 126 proteins in mouse and human.
- Experimental evidence confirmed dATI for specific proteins, including PABPC5 and PIF1α.
- Mitochondrial PABPC5 interacts with mitochondrial poly(A) polymerase and is involved in RNA metabolism.
Conclusions:
- Downstream ATI (dATI) is a mechanism for mitochondrial protein targeting.
- dATI significantly expands the repertoire of proteins localized to mitochondria.
- This mechanism reveals novel functions for proteins within the mitochondrial compartment.
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01:31Translation
Lesson: Translation
Translation is the process of synthesizing proteins from the genetic information carried by messenger RNA (mRNA). Following transcription, it constitutes the final step in the expression of genes. This process is carried out by ribosomes, complexes of protein and specialized RNA molecules. Ribosomes, transfer RNA (tRNA), and other proteins produce a chain of amino acids—the polypeptide—as the end product of translation.
Translation Produces the Building Blocks of Life
Translation is the process of synthesizing proteins from the genetic information carried by messenger RNA (mRNA). Following transcription, it constitutes the final step in the expression of genes. This process is carried out by ribosomes, complexes of protein and specialized RNA molecules. Ribosomes, transfer RNA (tRNA), and other proteins produce a chain of amino acids—the polypeptide—as the end product of translation.
Translation Produces the Building Blocks of Life
01:31Translation
Lesson: Translation
Translation is the process of synthesizing proteins from the genetic information carried by messenger RNA (mRNA). Following transcription, it constitutes the final step in the expression of genes. This process is carried out by ribosomes, complexes of protein and specialized RNA molecules. Ribosomes, transfer RNA (tRNA), and other proteins produce a chain of amino acids—the polypeptide—as the end product of translation.
Translation Produces the Building Blocks of Life
Translation is the process of synthesizing proteins from the genetic information carried by messenger RNA (mRNA). Following transcription, it constitutes the final step in the expression of genes. This process is carried out by ribosomes, complexes of protein and specialized RNA molecules. Ribosomes, transfer RNA (tRNA), and other proteins produce a chain of amino acids—the polypeptide—as the end product of translation.
Translation Produces the Building Blocks of Life