Yeast aconitase mitochondrial import is modulated by interactions of its C and N terminal domains and Ssa1/2 (Hsp70)

Reut Ben-Menachem; Katherine Wang; Orly Marcu; Zhang Yu; Teck Kwang Lim; Qingsong Lin; Ora Schueler-Furman; Ophry Pines

doi:10.1038/s41598-018-24068-w

Yeast aconitase mitochondrial import is modulated by interactions of its C and N terminal domains and Ssa1/2 (Hsp70)

Sci Rep. 2018 Apr 12;8(1):5903. doi: 10.1038/s41598-018-24068-w.

Authors

Reut Ben-Menachem¹, Katherine Wang², Orly Marcu¹, Zhang Yu², Teck Kwang Lim³, Qingsong Lin³, Ora Schueler-Furman¹, Ophry Pines^{4

5}

Affiliations

¹ Department of Microbiology and Molecular Genetics, IMRIC, Faculty of Medicine, Hebrew University, Jerusalem, Israel.
² CREATE-NUS-HUJ Program and the Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
³ Department of Biological Sciences, National University of Singapore, Singapore, Singapore.
⁴ Department of Microbiology and Molecular Genetics, IMRIC, Faculty of Medicine, Hebrew University, Jerusalem, Israel. ophryp@ekmd.huji.ac.il.
⁵ CREATE-NUS-HUJ Program and the Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore. ophryp@ekmd.huji.ac.il.

Abstract

Molecules of single proteins, echoforms, can be distributed between two (or more) subcellular locations, a phenomenon which we refer to as dual targeting or dual localization. The yeast aconitase gene ACO1 (778 amino acids), encodes a single translation product that is nonetheless dual localized to the cytosol and mitochondria by a reverse translocation mechanism. The solved crystal structure of aconitase isolated from porcine heart mitochondria shows that it has four domains. The first three tightly associated N-terminal domains are tethered to the larger C-terminal fourth domain (C-terminal amino acids 517-778). We have previously shown that the aconitase C terminal domain constitutes an independent dual targeting signal when fused to mitochondria-targeted passenger-proteins. We show that the aconitase N and C-terminal domains interact and that this interaction is important for efficient aconitase post translational import into mitochondria and for aconitase dual targeting (relative levels of aconitase echoforms). Our results suggest a "chaperone-like function" of the C terminal domain towards the N terminal domains which can be modulated by Ssa1/2 (cytosolic Hsp70).

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adenosine Triphosphatases / chemistry*
Adenosine Triphosphatases / genetics
Adenosine Triphosphatases / metabolism
Binding Sites
Cytosol / metabolism*
Gene Expression
Genetic Vectors / chemistry
Genetic Vectors / metabolism
HSP70 Heat-Shock Proteins / chemistry*
HSP70 Heat-Shock Proteins / genetics
HSP70 Heat-Shock Proteins / metabolism
Iron Regulatory Protein 1 / chemistry*
Iron Regulatory Protein 1 / genetics
Iron Regulatory Protein 1 / metabolism
Mitochondria / metabolism*
Models, Molecular
Mutation
Protein Binding
Protein Conformation, alpha-Helical
Protein Conformation, beta-Strand
Protein Interaction Domains and Motifs
Protein Transport
Recombinant Fusion Proteins / chemistry
Recombinant Fusion Proteins / genetics
Recombinant Fusion Proteins / metabolism
Saccharomyces cerevisiae / genetics
Saccharomyces cerevisiae / metabolism*
Saccharomyces cerevisiae Proteins / chemistry*
Saccharomyces cerevisiae Proteins / genetics
Saccharomyces cerevisiae Proteins / metabolism

Substances

HSP70 Heat-Shock Proteins
Recombinant Fusion Proteins
SSA2 protein, S cerevisiae
Saccharomyces cerevisiae Proteins
Adenosine Triphosphatases
SSA1 protein, S cerevisiae
Iron Regulatory Protein 1