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Muzafar S, Sharma RD, Chauhan N, Prasad R. Intron distribution and emerging role of alternative splicing in fungi. FEMS Microbiol Lett 2021; 368:6414529. [PMID: 34718529 DOI: 10.1093/femsle/fnab135] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Accepted: 10/28/2021] [Indexed: 12/16/2022] Open
Abstract
Spliceosomal introns are noncoding sequences that are spliced from pre-mRNA. They are ubiquitous in eukaryotic genomes, although the average number of introns per gene varies considerably between different eukaryotic species. Fungi are diverse in terms of intron numbers ranging from 4% to 99% genes with introns. Alternative splicing is one of the most common modes of posttranscriptional regulation in eukaryotes, giving rise to multiple transcripts from a single pre-mRNA and is widespread in metazoans and drives extensive proteome diversity. Earlier, alternative splicing was considered to be rare in fungi, but recently, increasing numbers of studies have revealed that alternative splicing is also widespread in fungi and has been implicated in the regulation of fungal growth and development, protein localization and the improvement of survivability, likely underlying their unique capacity to adapt to changing environmental conditions. However, the role of alternative splicing in pathogenicity and development of drug resistance is only recently gaining attention. In this review, we describe the intronic landscape in fungi. We also present in detail the newly discovered functions of alternative splicing in various cellular processes and outline areas particularly in pathogenesis and clinical drug resistance for future studies that could lead to the development of much needed new therapeutics.
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Affiliation(s)
- Suraya Muzafar
- Amity Institute of Integrative Sciences and Health, Amity University Gurgaon, Gurgaon 122413, Haryana, India
| | - Ravi Datta Sharma
- Amity Institute of Integrative Sciences and Health, Amity University Gurgaon, Gurgaon 122413, Haryana, India
| | - Neeraj Chauhan
- Public Health Research Institute, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
| | - Rajendra Prasad
- Amity Institute of Integrative Sciences and Health, Amity University Gurgaon, Gurgaon 122413, Haryana, India
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Characterization of Single Gene Deletion Mutants Affecting Alternative Oxidase Production in Neurospora crassa: Role of the yvh1 Gene. Microorganisms 2020; 8:microorganisms8081186. [PMID: 32759834 PMCID: PMC7463738 DOI: 10.3390/microorganisms8081186] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 07/29/2020] [Accepted: 07/31/2020] [Indexed: 01/21/2023] Open
Abstract
The Neurospora crassa AOD1 protein is a mitochondrial alternative oxidase that passes electrons directly from ubiquinol to oxygen. The enzyme is encoded by the nuclear aod-1 gene and is produced when the standard electron transport chain is inhibited. We previously identified eleven strains in the N. crassa single gene deletion library that were severely deficient in their ability to produce AOD1 when grown in the presence of chloramphenicol, an inhibitor of mitochondrial translation that is known to induce the enzyme. Three mutants affected previously characterized genes. In this report we examined the remaining mutants and found that the deficiency of AOD1 was due to secondary mutations in all but two of the strains. One of the authentic mutants contained a deletion of the yvh1 gene and was found to have a deficiency of aod-1 transcripts. The YVH1 protein localized to the nucleus and a post mitochondrial pellet from the cytoplasm. A zinc binding domain in the protein was required for rescue of the AOD1 deficiency. In other organisms YVH1 is required for ribosome assembly and mutants have multiple phenotypes. Lack of YVH1 in N. crassa likely also affects ribosome assembly leading to phenotypes that include altered regulation of AOD1 production.
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Qi Z, Smith KM, Bredeweg EL, Bosnjak N, Freitag M, Nargang FE. Alternative Oxidase Transcription Factors AOD2 and AOD5 of Neurospora crassa Control the Expression of Genes Involved in Energy Production and Metabolism. G3 (BETHESDA, MD.) 2017; 7:449-466. [PMID: 27986792 PMCID: PMC5295593 DOI: 10.1534/g3.116.035402] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/11/2016] [Accepted: 11/22/2016] [Indexed: 01/16/2023]
Abstract
In Neurospora crassa, blocking the function of the standard mitochondrial electron transport chain results in the induction of an alternative oxidase (AOX). AOX transfers electrons directly from ubiquinol to molecular oxygen. AOX serves as a model of retrograde regulation since it is encoded by a nuclear gene that is regulated in response to signals from mitochondria. The N. crassa transcription factors AOD2 and AOD5 are necessary for the expression of the AOX gene. To gain insight into the mechanism by which these factors function, and to determine if they have roles in the expression of additional genes in N. crassa, we constructed strains expressing only tagged versions of the proteins. Cell fractionation experiments showed that both proteins are localized to the nucleus under both AOX inducing and noninducing conditions. Furthermore, chromatin immunoprecipitation and high throughput sequencing (ChIP-seq) analysis revealed that the proteins are bound to the promoter region of the AOX gene under both conditions. ChIP-seq also showed that the transcription factors bind to the upstream regions of a number of genes that are involved in energy production and metabolism. Dependence on AOD2 and AOD5 for the expression of several of these genes was verified by quantitative PCR. The majority of ChIP-seq peaks observed were enriched for both AOD2 and AOD5. However, we also observed occasional sites where one factor appeared to bind preferentially. The most striking of these was a conserved sequence that bound large amounts of AOD2 but little AOD5. This sequence was found within a 310 bp repeat unit that occurs at several locations in the genome.
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Affiliation(s)
- Zhigang Qi
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
| | - Kristina M Smith
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331-4003
| | - Erin L Bredeweg
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331-4003
| | - Natasa Bosnjak
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
| | - Michael Freitag
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331-4003
| | - Frank E Nargang
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
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Lackey SWK, Taylor RD, Go NE, Wong A, Sherman EL, Nargang FE. Evidence supporting the 19 β-strand model for Tom40 from cysteine scanning and protease site accessibility studies. J Biol Chem 2014; 289:21640-50. [PMID: 24947507 DOI: 10.1074/jbc.m114.578765] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Most proteins found in mitochondria are translated in the cytosol and enter the organelle via the TOM complex (translocase of the outer mitochondrial membrane). Tom40 is the pore forming component of the complex. Although the three-dimensional structure of Tom40 has not been determined, the structure of porin, a related protein, has been shown to be a β-barrel containing 19 membrane spanning β-strands and an N-terminal α-helical region. The evolutionary relationship between the two proteins has allowed modeling of Tom40 into a similar structure by several laboratories. However, it has been suggested that the 19-strand porin structure does not represent the native form of the protein. If true, modeling of Tom40 based on the porin structure would also be invalid. We have used substituted cysteine accessibility mapping to identify several potential β-strands in the Tom40 protein in isolated mitochondria. These data, together with protease accessibility studies, support the 19 β-strand model for Tom40 with the C-terminal end of the protein localized to the intermembrane space.
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Affiliation(s)
- Sebastian W K Lackey
- From the Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
| | - Rebecca D Taylor
- From the Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
| | - Nancy E Go
- From the Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
| | - Annie Wong
- From the Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
| | - E Laura Sherman
- From the Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
| | - Frank E Nargang
- From the Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
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Wideman JG, Lackey SWK, Srayko MA, Norton KA, Nargang FE. Analysis of mutations in Neurospora crassa ERMES components reveals specific functions related to β-barrel protein assembly and maintenance of mitochondrial morphology. PLoS One 2013; 8:e71837. [PMID: 23940790 PMCID: PMC3733929 DOI: 10.1371/journal.pone.0071837] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2013] [Accepted: 07/03/2013] [Indexed: 11/22/2022] Open
Abstract
The endoplasmic reticulum mitochondria encounter structure (ERMES) tethers the er to mitochondria and contains four structural components: Mmm1, Mdm12, Mdm10, and Mmm2 (Mdm34). The Gem1 protein may play a role in regulating ERMES function. Saccharomyces cerevisiae and Neurospora crassa strains lacking any of Mmm1, Mdm12, or Mdm10 are known to show a variety of phenotypic defects including altered mitochondrial morphology and defects in the assembly of β-barrel proteins into the mitochondrial outer membrane. Here we examine ERMES complex components in N. crassa and show that Mmm1 is an ER membrane protein containing a Cys residue near its N-terminus that is conserved in the class Sordariomycetes. The residue occurs in the ER-lumen domain of the protein and is involved in the formation of disulphide bonds that give rise to Mmm1 dimers. Dimer formation is required for efficient assembly of Tom40 into the TOM complex. However, no effects are seen on porin assembly or mitochondrial morphology. This demonstrates a specificity of function and suggests a direct role for Mmm1 in Tom40 assembly. Mutation of a highly conserved region in the cytosolic domain of Mmm1 results in moderate defects in Tom40 and porin assembly, as well as a slight morphological phenotype. Previous reports have not examined the role of Mmm2 with respect to mitochondrial protein import and assembly. Here we show that absence of Mmm2 affects assembly of β-barrel proteins and that lack of any ERMES structural component results in defects in Tom22 assembly. Loss of N. crassa Gem1 has no effect on the assembly of these proteins but does affect mitochondrial morphology.
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Affiliation(s)
- Jeremy G. Wideman
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | | | - Martin A. Srayko
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Kacie A. Norton
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Frank E. Nargang
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
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Duncan O, van der Merwe MJ, Daley DO, Whelan J. The outer mitochondrial membrane in higher plants. TRENDS IN PLANT SCIENCE 2013; 18:207-17. [PMID: 23291162 DOI: 10.1016/j.tplants.2012.12.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Revised: 11/29/2012] [Accepted: 12/05/2012] [Indexed: 05/11/2023]
Abstract
The acquisition and integration of intracellular organelles, such as mitochondria and plastids, were important steps in the emergence of complex multicellular life. Although the outer membranes of these organelles have lost many of the functions of their free-living bacterial ancestor, others were acquired during organellogenesis. To date, the biological roles of these proteins have not been systematically characterized. In this review, we discuss the evolutionary origins and functions of outer membrane mitochondrial (OMM) proteins in Arabidopsis thaliana. Our analysis, using phylogenetic inference, indicates that several OMM proteins either acquired novel functional roles or were recruited from other subcellular localizations during evolution in Arabidopsis. These observations suggest the existence of novel communication routes and functions between organelles within plant cells.
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Affiliation(s)
- Owen Duncan
- ARC Centre of Excellence in Plant Energy Biology, MCS Building M316, University of Western Australia, Crawley, WA 6009, Australia
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7
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Kempken F. Alternative splicing in ascomycetes. Appl Microbiol Biotechnol 2013; 97:4235-41. [DOI: 10.1007/s00253-013-4841-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2013] [Revised: 03/06/2013] [Accepted: 03/06/2013] [Indexed: 01/08/2023]
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Klein A, Israel L, Lackey SWK, Nargang FE, Imhof A, Baumeister W, Neupert W, Thomas DR. Characterization of the insertase for β-barrel proteins of the outer mitochondrial membrane. ACTA ACUST UNITED AC 2012; 199:599-611. [PMID: 23128244 PMCID: PMC3494861 DOI: 10.1083/jcb.201207161] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Isolation of the intact TOB complex reveals a 1:1:1 stoichiometry of Tob55, Tob38, and Tob37 with a 140-kD molecular mass, providing new insight into complex structure and function. The TOB–SAM complex is an essential component of the mitochondrial outer membrane that mediates the insertion of β-barrel precursor proteins into the membrane. We report here its isolation and determine its size, composition, and structural organization. The complex from Neurospora crassa was composed of Tob55–Sam50, Tob38–Sam35, and Tob37–Sam37 in a stoichiometry of 1:1:1 and had a molecular mass of 140 kD. A very minor fraction of the purified complex was associated with one Mdm10 protein. Using molecular homology modeling for Tob55 and cryoelectron microscopy reconstructions of the TOB complex, we present a model of the TOB–SAM complex that integrates biochemical and structural data. We discuss our results and the structural model in the context of a possible mechanism of the TOB insertase.
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Affiliation(s)
- Astrid Klein
- Max-Planck Institut für Biochemie, Abteilung für zelluläre Biochemie, D-82152 Martinsried, Germany
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Lackey SWK, Wideman JG, Kennedy EK, Go NE, Nargang FE. The Neurospora crassa TOB complex: analysis of the topology and function of Tob38 and Tob37. PLoS One 2011; 6:e25650. [PMID: 21980517 PMCID: PMC3182244 DOI: 10.1371/journal.pone.0025650] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Accepted: 09/07/2011] [Indexed: 11/18/2022] Open
Abstract
The TOB or SAM complex is responsible for assembling several proteins into the mitochondrial outer membrane, including all β-barrel proteins. We have identified several forms of the complex in Neurospora crassa. One form contains Tob55, Tob38, and Tob37; another contains these three subunits plus the Mdm10 protein; while additional complexes contain only Tob55. As previously shown for Tob55, both Tob37 and Tob38 are essential for viability of the organism. Mitochondria deficient in Tob37 or Tob38 have reduced ability to assemble β-barrel proteins. The function of two hydrophobic domains in the C-terminal region of the Tob37 protein was investigated. Mutant Tob37 proteins lacking either or both of these regions are able to restore viability to cells lacking the protein. One of the domains was found to anchor the protein to the outer mitochondrial membrane but was not necessary for targeting or association of the protein with mitochondria. Examination of the import properties of mitochondria containing Tob37 with deletions of the hydrophobic domains reveals that the topology of Tob37 may be important for interactions between specific classes of β-barrel precursors and the TOB complex.
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Affiliation(s)
| | - Jeremy G. Wideman
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Erin K. Kennedy
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Nancy E. Go
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Frank E. Nargang
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
- * E-mail:
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Schleiff E, Maier UG, Becker T. Omp85 in eukaryotic systems: one protein family with distinct functions. Biol Chem 2011; 392:21-7. [DOI: 10.1515/bc.2011.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
AbstractOmp85-like proteins are evolutionary ancient components of bacterial outer membranes and their evolutionary offspring. As a consequence, proteins of this family can be found in the outer membrane systems of Gram-negative bacteria and endosymbiotically derived organelles. In the different membranes, they perform distinct functions such as catalyzing protein insertion into or protein transport across the bilayer. Here, the knowledge on the Omp85-like proteins in the eukaryotic system with regard to structural properties and physiological behavior is summarized.
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11
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Evidence of alternative splicing of the chi2 chitinase gene from Metarhizium anisopliae. Gene 2010; 462:1-7. [DOI: 10.1016/j.gene.2010.04.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2009] [Revised: 04/09/2010] [Accepted: 04/13/2010] [Indexed: 11/17/2022]
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12
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Wideman JG, Go NE, Klein A, Redmond E, Lackey SWK, Tao T, Kalbacher H, Rapaport D, Neupert W, Nargang FE. Roles of the Mdm10, Tom7, Mdm12, and Mmm1 proteins in the assembly of mitochondrial outer membrane proteins in Neurospora crassa. Mol Biol Cell 2010; 21:1725-36. [PMID: 20335503 PMCID: PMC2869378 DOI: 10.1091/mbc.e09-10-0844] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Mdm10, Mdm12, and Mmm1 are implicated in several mitochondrial functions. We show that loss of any of these proteins in Neurospora crassa results in the formation of large mitochondrial tubules and reduces assembly of porin and Tom40. The effects of mutations affecting Tom7 and Mdm10 are additive with respect to the assembly of Tom40 and porin. The Mdm10, Mdm12, and Mmm1 proteins have been implicated in several mitochondrial functions including mitochondrial distribution and morphology, assembly of β-barrel proteins such as Tom40 and porin, association of mitochondria and endoplasmic reticulum, and maintaining lipid composition of mitochondrial membranes. Here we show that loss of any of these three proteins in Neurospora crassa results in the formation of large mitochondrial tubules and reduces the assembly of porin and Tom40 into the outer membrane. We have also investigated the relationship of Mdm10 and Tom7 in the biogenesis of β-barrel proteins. Previous work showed that mitochondria lacking Tom7 assemble Tom40 more efficiently, and porin less efficiently, than wild-type mitochondria. Analysis of mdm10 and tom7 single and double mutants, has demonstrated that the effects of the two mutations are additive. Loss of Tom7 partially compensates for the decrease in Tom40 assembly resulting from loss of Mdm10, whereas porin assembly is more severely reduced in the double mutant than in either single mutant. The additive effects observed in the double mutant suggest that different steps in β-barrel assembly are affected in the individual mutants. Many aspects of Tom7 and Mdm10 function in N. crassa are different from those of their homologues in Saccharomyces cerevisiae.
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Affiliation(s)
- Jeremy G Wideman
- Department of Biological Sciences, University of Alberta, Alberta, Canada
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Wittig I, Schägger H. Features and applications of blue-native and clear-native electrophoresis. Proteomics 2008; 8:3974-90. [DOI: 10.1002/pmic.200800017] [Citation(s) in RCA: 136] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Walther DM, Rapaport D. Biogenesis of mitochondrial outer membrane proteins. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2008; 1793:42-51. [PMID: 18501716 DOI: 10.1016/j.bbamcr.2008.04.013] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/29/2008] [Revised: 04/15/2008] [Accepted: 04/25/2008] [Indexed: 11/29/2022]
Abstract
Mitochondria are surrounded by two distinct membranes: the outer and the inner membrane. The mitochondrial outer membrane mediates numerous interactions between the mitochondrial metabolic and genetic systems and the rest of the eukaryotic cell. Proteins of this membrane are nuclear-encoded and synthesized as precursor proteins in the cytosol. They are targeted to the mitochondria and inserted into their target membrane via various pathways. This review summarizes our current knowledge of the sorting signals for this specific targeting and describes the mechanisms by which the mitochondrial import machineries recognize precursor proteins, mediate their membrane integration and facilitate assembly into functional complexes.
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Affiliation(s)
- Dirk M Walther
- Interfakultäres Institut für Biochemie, Hoppe-Seyler-Str. 4, University of Tübingen, 72076 Tübingen, Germany
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Chapter 5 New Insights into the Mechanism of Precursor Protein Insertion into the Mitochondrial Membranes. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2008; 268:147-90. [DOI: 10.1016/s1937-6448(08)00805-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/10/2023]
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Stojanovski D, Guiard B, Kozjak-Pavlovic V, Pfanner N, Meisinger C. Alternative function for the mitochondrial SAM complex in biogenesis of alpha-helical TOM proteins. ACTA ACUST UNITED AC 2007; 179:881-93. [PMID: 18039934 PMCID: PMC2099199 DOI: 10.1083/jcb.200706043] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The mitochondrial outer membrane contains two preprotein translocases: the general translocase of outer membrane (TOM) and the β-barrel–specific sorting and assembly machinery (SAM). TOM functions as the central entry gate for nuclear-encoded proteins. The channel-forming Tom40 is a β-barrel protein, whereas all Tom receptors and small Tom proteins are membrane anchored by a transmembrane α-helical segment in their N- or C-terminal portion. Synthesis of Tom precursors takes place in the cytosol, and their import occurs via preexisting TOM complexes. The precursor of Tom40 is then transferred to SAM for membrane insertion and assembly. Unexpectedly, we find that the biogenesis of α-helical Tom proteins with a membrane anchor in the C-terminal portion is SAM dependent. Each SAM protein is necessary for efficient membrane integration of the receptor Tom22, whereas assembly of the small Tom proteins depends on Sam37. Thus, the substrate specificity of SAM is not restricted to β-barrel proteins but also includes the majority of α-helical Tom proteins.
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Affiliation(s)
- Diana Stojanovski
- Institut für Biochemie und Molekularbiologie, Zentrum für Biochemie und Molekulare Zellforschung, Universität Freiburg, D-79104 Freiburg, Germany
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