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Dual targeted mitochondrial proteins are characterized by lower MTS parameters and total net charge.

Dinur-Mills M, Tal M, Pines O - PLoS ONE (2008)

Bottom Line: Mitochondrial proteins were considered dual-targeted if they were also found or predicted to be localized to the cytosol, the nucleus, the endoplasmic reticulum (ER) or the peroxisome.We found that dual localized mitochondrial proteins have i) A weaker mitochondrial targeting sequence (MitoProtII score, hydrophobic moment and number of basic residues) and ii) a lower whole-protein net charge, when compared to exclusive mitochondrial proteins.Taken together, these results establish dual targeting as a widely abundant phenomenon that should affect our concepts of gene expression and protein function.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Biology, Hebrew University Medical School, Jerusalem, Israel.

ABSTRACT

Background: In eukaryotic cells, identical proteins can be located in different subcellular compartments (termed dual-targeted proteins).

Methodology/principal findings: We divided a reference set of mitochondrial proteins (published single gene studies) into two groups: i) Dual targeted mitochondrial proteins and ii) Exclusive mitochondrial proteins. Mitochondrial proteins were considered dual-targeted if they were also found or predicted to be localized to the cytosol, the nucleus, the endoplasmic reticulum (ER) or the peroxisome. We found that dual localized mitochondrial proteins have i) A weaker mitochondrial targeting sequence (MitoProtII score, hydrophobic moment and number of basic residues) and ii) a lower whole-protein net charge, when compared to exclusive mitochondrial proteins. We have also generated an annotation list of dual-targeted proteins within the predicted yeast mitochondrial proteome. This considerably large group of dual-localized proteins comprises approximately one quarter of the predicted mitochondrial proteome. We supported this prediction by experimental verification of a subgroup of the predicted dual targeted proteins.

Conclusions/significance: Taken together, these results establish dual targeting as a widely abundant phenomenon that should affect our concepts of gene expression and protein function. Possible relationships between the MTS/mature sequence traits and protein dual targeting are discussed.

Show MeSH
α-complementation assay for mitochondrial and cytosolic location of predicted dual (A) and nondual (B) localized proteins.Yeast expressing the indicated α fusion proteins and the ωc or ωm fragments were tested for color production on galactose medium, X-gal agar plates.
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pone-0002161-g003: α-complementation assay for mitochondrial and cytosolic location of predicted dual (A) and nondual (B) localized proteins.Yeast expressing the indicated α fusion proteins and the ωc or ωm fragments were tested for color production on galactose medium, X-gal agar plates.

Mentions: Seven out of the nine proteins predicted to be dual-localized to mitochondria and the cytosol (Fig. 3A) exhibited a color phenotype corresponding to the expected dual localization, while two appeared to be exclusively mitochondrial. In comparison only one protein (GCV3) predicted to have an exclusive mitochondrial location exhibited dual localization phenotype while four out of these five proteins exhibited as predicted an exclusive mitochondrial phenotype (Fig. 3B). These results support our contention of abundant dual targeting of mitochondrial proteins in yeast.


Dual targeted mitochondrial proteins are characterized by lower MTS parameters and total net charge.

Dinur-Mills M, Tal M, Pines O - PLoS ONE (2008)

α-complementation assay for mitochondrial and cytosolic location of predicted dual (A) and nondual (B) localized proteins.Yeast expressing the indicated α fusion proteins and the ωc or ωm fragments were tested for color production on galactose medium, X-gal agar plates.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2367453&req=5

pone-0002161-g003: α-complementation assay for mitochondrial and cytosolic location of predicted dual (A) and nondual (B) localized proteins.Yeast expressing the indicated α fusion proteins and the ωc or ωm fragments were tested for color production on galactose medium, X-gal agar plates.
Mentions: Seven out of the nine proteins predicted to be dual-localized to mitochondria and the cytosol (Fig. 3A) exhibited a color phenotype corresponding to the expected dual localization, while two appeared to be exclusively mitochondrial. In comparison only one protein (GCV3) predicted to have an exclusive mitochondrial location exhibited dual localization phenotype while four out of these five proteins exhibited as predicted an exclusive mitochondrial phenotype (Fig. 3B). These results support our contention of abundant dual targeting of mitochondrial proteins in yeast.

Bottom Line: Mitochondrial proteins were considered dual-targeted if they were also found or predicted to be localized to the cytosol, the nucleus, the endoplasmic reticulum (ER) or the peroxisome.We found that dual localized mitochondrial proteins have i) A weaker mitochondrial targeting sequence (MitoProtII score, hydrophobic moment and number of basic residues) and ii) a lower whole-protein net charge, when compared to exclusive mitochondrial proteins.Taken together, these results establish dual targeting as a widely abundant phenomenon that should affect our concepts of gene expression and protein function.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Biology, Hebrew University Medical School, Jerusalem, Israel.

ABSTRACT

Background: In eukaryotic cells, identical proteins can be located in different subcellular compartments (termed dual-targeted proteins).

Methodology/principal findings: We divided a reference set of mitochondrial proteins (published single gene studies) into two groups: i) Dual targeted mitochondrial proteins and ii) Exclusive mitochondrial proteins. Mitochondrial proteins were considered dual-targeted if they were also found or predicted to be localized to the cytosol, the nucleus, the endoplasmic reticulum (ER) or the peroxisome. We found that dual localized mitochondrial proteins have i) A weaker mitochondrial targeting sequence (MitoProtII score, hydrophobic moment and number of basic residues) and ii) a lower whole-protein net charge, when compared to exclusive mitochondrial proteins. We have also generated an annotation list of dual-targeted proteins within the predicted yeast mitochondrial proteome. This considerably large group of dual-localized proteins comprises approximately one quarter of the predicted mitochondrial proteome. We supported this prediction by experimental verification of a subgroup of the predicted dual targeted proteins.

Conclusions/significance: Taken together, these results establish dual targeting as a widely abundant phenomenon that should affect our concepts of gene expression and protein function. Possible relationships between the MTS/mature sequence traits and protein dual targeting are discussed.

Show MeSH