共查询到20条相似文献,搜索用时 15 毫秒
1.
Mcp3 is a novel mitochondrial outer membrane protein that follows a unique IMP‐dependent biogenesis pathway
下载免费PDF全文
![点击此处可从《EMBO reports》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Monika Sinzel Tao Tan Philipp Wendling Hubert Kalbacher Cagakan Özbalci Xenia Chelius Benedikt Westermann Britta Brügger Doron Rapaport Kai Stefan Dimmer 《EMBO reports》2016,17(7):965-981
Mitochondria are separated from the remainder of the eukaryotic cell by the mitochondrial outer membrane (MOM). The MOM plays an important role in different transport processes like lipid trafficking and protein import. In yeast, the ER–mitochondria encounter structure (ERMES) has a central, but poorly defined role in both activities. To understand the functions of the ERMES, we searched for suppressors of the deficiency of one of its components, Mdm10, and identified a novel mitochondrial protein that we named Mdm10 complementing protein 3 (Mcp3). Mcp3 partially rescues a variety of ERMES‐related phenotypes. We further demonstrate that Mcp3 is an integral protein of the MOM that follows a unique import pathway. It is recognized initially by the import receptor Tom70 and then crosses the MOM via the translocase of the outer membrane. Mcp3 is next relayed to the TIM23 translocase at the inner membrane, gets processed by the inner membrane peptidase (IMP) and finally integrates into the MOM. Hence, Mcp3 follows a novel biogenesis route where a MOM protein is processed by a peptidase of the inner membrane. 相似文献
2.
The mitochondrial outer membrane (MOM) harbors several multispan proteins that execute various functions. Despite their importance, the mechanisms by which these proteins are recognized and inserted into the outer membrane remain largely unclear. In this paper, we address this issue using yeast mitochondria and the multispan protein Ugo1. Using a specific insertion assay and analysis by native gel electrophoresis, we show that the import receptor Tom70, but not its partner Tom20, is involved in the initial recognition of the Ugo1 precursor. Surprisingly, the import pore formed by the translocase of the outer membrane complex appears not to be required for the insertion process. Conversely, the multifunctional outer membrane protein mitochondrial import 1 (Mim1) plays a central role in mediating the insertion of Ugo1. Collectively, these results suggest that Ugo1 is inserted into the MOM by a novel pathway in which Tom70 and Mim1 contribute to the efficiency and selectivity of the process. 相似文献
3.
The understanding of the biogenesis of the outer membrane of Gram‐negative bacteria is of critical importance due to the emergence of bacteria that are becoming resistant to available antibiotics. A problem that is most serious for Gram‐negative bacteria, with essentially few antibiotics under development or likely to be available for clinical use in the near future. The understanding of the Gram‐negative bacterial outer membrane is therefore critical to developing new antimicrobial agents, as this membrane makes direct contact with the external milieu, and the proteins present within this membrane are the instruments of microbial warfare, playing key roles in microbial pathogenesis, virulence and multidrug resistance. To date, a single outer membrane complex has been identified as essential for the folding and insertion of proteins into the outer membrane, this is the β‐barrel assembly machine (BAM) complex, which in some cases is supplemented by the Translocation and Assembly Module (TAM). In this issue of Molecular Microbiology, Dunstan et al. have identified a novel pathway for the insertion of a subset of integral membrane proteins into the Gram‐negative outer membrane that is independent of the BAM complex and TAM. 相似文献
4.
Meineke B Engl G Kemper C Vasiljev-Neumeyer A Paulitschke H Rapaport D 《FEBS letters》2008,582(6):855-860
The yeast gene MCR1 encodes two isoforms of the mitochondrial NADH-cytochrome b5 reductase. One form is embedded in the outer membrane whereas the other is located in the intermembrane space (IMS). In the present work we investigated the biogenesis of the outer membrane form. We demonstrate that while the IMS form crosses the outer membrane via the translocase of the outer mitochondrial membrane (TOM) complex, the other form is integrated into the outer membrane by a process that does not require any of the known import components at the outer membrane. Thus, the import pathways of the two forms diverge in a stage before the encounter with the TOM complex and their mechanism of biogenesis represents a unique example how to achieve dual localization within one organelle. 相似文献
5.
The majority of mitochondrial proteins are nuclear-encoded and need to be transported into the mitochondria, including the proteins in the outer mitochondrial membrane. For β-barrel proteins, the preproteins are initially recognized and imported by the TOM complex, then shuttled to the SAM complex via small Tim proteins. For ⍺-helical proteins, some preproteins are recognized by the TOM complex and imported into the membrane by the MIM complex. In recent years multiple structures of the TOM complex and the SAM complex have been reported, increasing our understanding of the mechanism of protein biogenesis in the outer mitochondrial membrane. 相似文献
6.
The presequence pathway is involved in protein sorting to the mitochondrial outer membrane
下载免费PDF全文
![点击此处可从《EMBO reports》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Lena‐Sophie Wenz Łukasz Opaliński Max‐Hinderk Schuler Lars Ellenrieder Raffaele Ieva Lena Böttinger Jian Qiu Martin van der Laan Nils Wiedemann Bernard Guiard Nikolaus Pfanner Thomas Becker 《EMBO reports》2014,15(6):678-685
The mitochondrial outer membrane contains integral α-helical and β-barrel proteins that are imported from the cytosol. The machineries importing β-barrel proteins have been identified, however, different views exist on the import of α-helical proteins. It has been reported that the biogenesis of Om45, the most abundant signal-anchored protein, does not depend on proteinaceous components, but involves direct insertion into the outer membrane. We show that import of Om45 occurs via the translocase of the outer membrane and the presequence translocase of the inner membrane. Assembly of Om45 in the outer membrane involves the MIM machinery. Om45 thus follows a new mitochondrial biogenesis pathway that uses elements of the presequence import pathway to direct a protein to the outer membrane. 相似文献
7.
Becker T Wenz LS Krüger V Lehmann W Müller JM Goroncy L Zufall N Lithgow T Guiard B Chacinska A Wagner R Meisinger C Pfanner N 《The Journal of cell biology》2011,194(3):387-395
The mitochondrial outer membrane contains translocase complexes for the import of precursor proteins. The translocase of the outer membrane complex functions as a general preprotein entry gate, whereas the sorting and assembly machinery complex mediates membrane insertion of β-barrel proteins of the outer membrane. Several α-helical outer membrane proteins are known to carry multiple transmembrane segments; however, only limited information is available on the biogenesis of these proteins. We report that mitochondria lacking the mitochondrial import protein 1 (Mim1) are impaired in the biogenesis of multispanning outer membrane proteins, whereas overexpression of Mim1 stimulates their import. The Mim1 complex cooperates with the receptor Tom70 in binding of precursor proteins and promotes their insertion and assembly into the outer membrane. We conclude that the Mim1 complex plays a central role in the import of α-helical outer membrane proteins with multiple transmembrane segments. 相似文献
8.
Yusuke Shiromoto Satomi Kuramochi-Miyagawa Akito Daiba Shinichiro Chuma Ami Katanaya Akiko Katsumata Ken Nishimura Manami Ohtaka Mahito Nakanishi Toshinobu Nakamura Koichi Yoshinaga Noriko Asada Shota Nakamura Teruo Yasunaga Kanako Kojima-Kita Daisuke Itou Tohru Kimura Toru Nakano 《RNA (New York, N.Y.)》2013,19(6):803-810
piRNA (PIWI-interacting RNA) is a germ cell–specific small RNA in which biogenesis PIWI (P-element wimpy testis) family proteins play crucial roles. MILI (mouse Piwi-like), one of the three mouse PIWI family members, is indispensable for piRNA production, DNA methylation of retrotransposons presumably through the piRNA, and spermatogenesis. The biogenesis of piRNA has been divided into primary and secondary processing pathways; in both of these MILI is involved in mice. To analyze the molecular function of MILI in piRNA biogenesis, we utilized germline stem (GS) cells, which are derived from testicular stem cells and possess a spermatogonial phenotype. We established MILI-null GS cell lines and their revertant, MILI-rescued GS cells, by introducing the Mili gene with Sendai virus vector. Comparison of wild-type, MILI-null, and MILI-rescued GS cells revealed that GS cells were quite useful for analyzing the molecular mechanisms of piRNA production, especially the primary processing pathway. We found that glycerol-3-phosphate acyltransferase 2 (GPAT2), a mitochondrial outer membrane protein for lysophosphatidic acid, bound to MILI using the cells and that gene knockdown of GPAT2 brought about impaired piRNA production in GS cells. GPAT2 is not only one of the MILI bound proteins but also a protein essential for primary piRNA biogenesis. 相似文献
9.
F.-Nora V?gtle Michael Keller Asli A. Taskin Susanne E. Horvath Xue Li Guan Claudia Prinz Magdalena Opalińska Carina Zorzin Martin van der Laan Markus R. Wenk Rolf Schubert Nils Wiedemann Martin Holzer Chris Meisinger 《The Journal of cell biology》2015,210(6):951-960
Import and assembly of mitochondrial proteins depend on a complex interplay of
proteinaceous translocation machineries. The role of lipids in this process has been
studied only marginally and so far no direct role for a specific lipid in
mitochondrial protein biogenesis has been shown. Here we analyzed a potential role of
phosphatidic acid (PA) in biogenesis of mitochondrial proteins in
Saccharomyces cerevisiae. In vivo remodeling of the mitochondrial
lipid composition by lithocholic acid treatment or by ablation of the lipid transport
protein Ups1, both leading to an increase of mitochondrial PA levels, specifically
stimulated the biogenesis of the outer membrane protein Ugo1, a component of the
mitochondrial fusion machinery. We reconstituted the import and assembly pathway of
Ugo1 in protein-free liposomes, mimicking the outer membrane phospholipid
composition, and found a direct dependency of Ugo1 biogenesis on PA. Thus, PA
represents the first lipid that is directly involved in the biogenesis pathway of a
mitochondrial membrane protein. 相似文献
10.
Saccharomyces cerevisiae acyl-CoA oxidase follows a novel, non-PTS1, import pathway into peroxisomes that is dependent on Pex5p 总被引:4,自引:0,他引:4
Klein AT van den Berg M Bottger G Tabak HF Distel B 《The Journal of biological chemistry》2002,277(28):25011-25019
The peroxisomal protein acyl-CoA oxidase (Pox1p) of Saccharomyces cerevisiae lacks either of the two well characterized peroxisomal targeting sequences known as PTS1 and PTS2. Here we demonstrate that peroxisomal import of Pox1p is nevertheless dependent on binding to Pex5p, the PTS1 import receptor. The interaction between Pex5p and Pox1p, however, involves novel contact sites in both proteins. The interaction region in Pex5p is located in a defined area of the amino-terminal part of the protein outside of the tetratricopeptide repeat domain involved in PTS1 recognition; the interaction site in Pox1p is located internally and not at the carboxyl terminus where a PTS1 is normally found. By making use of pex5 mutants that are either specifically disturbed in binding of PTS1 proteins or in binding of Pox1p, we demonstrate the existence of two independent, Pex5p-mediated import pathways into peroxisomes in yeast as follows: a classical PTS1 pathway and a novel, non-PTS1 pathway for Pox1p. 相似文献
11.
Identification of an outer mitochondrial membrane protein that interacts with a synthetic signal peptide 总被引:5,自引:0,他引:5
L L Gillespie 《The Journal of biological chemistry》1987,262(17):7939-7942
Chemical cross-linking procedures have been employed to study possible interactions between components of the mitochondrial outer membrane and NH2-terminal signal sequences located in proteins destined for import into the organelle. A synthetic peptide comprising amino acids 1-27 of pre-ornithine carbamyltransferase (pOCT) was found to interact specifically with a mitochondrial polypeptide of apparent molecular size 30 kDa. Membrane fractionation and protease accessibility analyses indicated that the polypeptide, designated p30, is located in the outer membrane. Binding of the synthetic peptide to p30 was saturable and reversible; Scatchard analysis of the binding data revealed a dissociation constant of 2 X 10(-6) M and predicts that p30 constitutes 4-10% of the outer mitochondrial membrane protein. Mild trypsin digestion of the mitochondrial surface destroyed both the ability of p30 to cross-link to the signal peptide and the ability of the organelle to import pOCT. Neither parameter was affected, however, by pretreatment of mitochondria with 1 M KCl. 相似文献
12.
Three proteins with similar effects on mitochondrial morphology were identified in an RNA interference (RNAi) screen for mitochondrial abnormalities in Caenorhabditis elegans. One of these is the novel mitochondrial outer membrane protein MOMA-1. The second is the CHCHD3 homologue, CHCH-3, a small intermembrane space protein that may act as a chaperone. The third is a mitofilin homologue, IMMT-1. Mitofilins are inner membrane proteins that control the shapes of cristae. RNAi or mutations in each of these genes change the relatively constant diameters of mitochondria into highly variable diameters, ranging from thin tubes to localized swellings. Neither growth nor brood size of the moma-1, chch-3, or immt-1 single mutants is affected, suggesting that their metabolic functions are normal. However, growth of moma-1 or immt-1 mutants on chch-3(RNAi) leads to withered gonads, a lack of mitochondrial staining, and a dramatic reduction in fecundity, while moma-1; immt-1 double mutants are indistinguishable from single mutants. Mutations in moma-1 and immt-1 also have similar effects on cristae morphology. We conclude that MOMA-1 and IMMT-1 act in the same pathway. It is likely that the observed effects on mitochondrial diameter are an indirect effect of disrupting cristae morphology. 相似文献
13.
Maria Bohnert Lena-Sophie Wenz Ralf M. Zerbes Susanne E. Horvath David A. Stroud Karina von der Malsburg Judith M. Müller Silke Oeljeklaus Inge Perschil Bettina Warscheid Agnieszka Chacinska Marten Veenhuis Ida J. van der Klei Günther Daum Nils Wiedemann Thomas Becker Nikolaus Pfanner Martin van der Laan 《Molecular biology of the cell》2012,23(20):3948-3956
Mitochondria contain two membranes, the outer membrane and the inner membrane with folded cristae. The mitochondrial inner membrane organizing system (MINOS) is a large protein complex required for maintaining inner membrane architecture. MINOS interacts with both preprotein transport machineries of the outer membrane, the translocase of the outer membrane (TOM) and the sorting and assembly machinery (SAM). It is unknown, however, whether MINOS plays a role in the biogenesis of outer membrane proteins. We have dissected the interaction of MINOS with TOM and SAM and report that MINOS binds to both translocases independently. MINOS binds to the SAM complex via the conserved polypeptide transport–associated domain of Sam50. Mitochondria lacking mitofilin, the large core subunit of MINOS, are impaired in the biogenesis of β-barrel proteins of the outer membrane, whereas mutant mitochondria lacking any of the other five MINOS subunits import β-barrel proteins in a manner similar to wild-type mitochondria. We show that mitofilin is required at an early stage of β-barrel biogenesis that includes the initial translocation through the TOM complex. We conclude that MINOS interacts with TOM and SAM independently and that the core subunit mitofilin is involved in biogenesis of outer membrane β-barrel proteins. 相似文献
14.
A novel insertion pathway of mitochondrial outer membrane proteins with multiple transmembrane segments 总被引:2,自引:0,他引:2
下载免费PDF全文
![点击此处可从《The Journal of cell biology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Otera H Taira Y Horie C Suzuki Y Suzuki H Setoguchi K Kato H Oka T Mihara K 《The Journal of cell biology》2007,179(7):1355-1363
The central channel Tom40 of the preprotein translocase of outer membrane (TOM) complex is thought to be responsible for the import of virtually all preproteins synthesized outside the mitochondria. In this study, we analyze the topogenesis of the peripheral benzodiazepine receptor (PBR), which integrates into the mitochondrial outer membrane (MOM) through five hydrophobic transmembrane segments (TMSs) and functions in cholesterol import into the inner membrane. Analyses of in vitro and in vivo import into TOM component–depleted mitochondria reveal that PBR import (1) depends on the import receptor Tom70 but requires neither the Tom20 and Tom22 import receptors nor the import channel Tom40, (2) shares the post-Tom70 pathway with the C-tail–anchored proteins, and (3) requires factors of the mitochondrial intermembrane space. Furthermore, membrane integration of mitofusins and mitochondrial ubiquitin ligase, the MOM proteins with two and four TMSs, respectively, proceeds through the same initial pathway. These findings reveal a previously unidentified pathway of the membrane integration of MOM proteins with multiple TMSs. 相似文献
15.
The L protein encoded by Theiler's murine encephalomyelitis virus (TMEV) is a unique example of a picornaviral protein encoded by an alternative open reading frame. This protein is an important determinant of TMEV persistence in the mouse central nervous system. We showed that in infected cells, L is partitioned between the cytosol and the mitochondria. In mitochondria, L is anchored in the outer membrane and exposed to the cytosol. The targeting of L to mitochondria is independent of other viral components and likely depends on a conformational signal. L targeting to mitochondria might involve chaperones of the Hsp70 family, as these proteins are shown to interact. 相似文献
16.
Ping Li Niloofar Nayeri Kamil Grecki Eva Ramos Becares Kaituo Wang Dhani Ram Mahato Magnus Andersson Sameera S. Abeyrathna Karin LindkvistPetersson Gabriele Meloni Julie Winkel Missel Pontus Gourdon 《Protein science : a publication of the Protein Society》2022,31(7)
Copper (Cu) is one of the most abundant trace metals in all organisms, involved in a plethora of cellular processes. Yet elevated concentrations of the element are harmful, and interestingly prokaryotes are more sensitive for environmental Cu stress than humans. Various transport systems are present to maintain intracellular Cu homeostasis, including the prokaryotic plasmid‐encoded multiprotein pco operon, which is generally assigned as a defense mechanism against elevated Cu concentrations. Here we structurally and functionally characterize the outer membrane component of the Pco system, PcoB, recovering a 2.0 Å structure, revealing a classical β‐barrel architecture. Unexpectedly, we identify a large opening on the extracellular side, linked to a considerably electronegative funnel that becomes narrower towards the periplasm, defining an ion‐conducting pathway as also supported by metal binding quantification via inductively coupled plasma mass spectrometry and molecular dynamics (MD) simulations. However, the structure is partially obstructed towards the periplasmic side, and yet flux is permitted in the presence of a Cu gradient as shown by functional characterization in vitro. Complementary in vivo experiments demonstrate that isolated PcoB confers increased sensitivity towards Cu. Aggregated, our findings indicate that PcoB serves to permit Cu import. Thus, it is possible the Pco system physiologically accumulates Cu in the periplasm as a part of an unorthodox defense mechanism against metal stress. These results point to a previously unrecognized principle of maintaining Cu homeostasis and may as such also assist in the understanding and in efforts towards combatting bacterial infections of Pco‐harboring pathogens. 相似文献
17.
Mitochondrial outer and inner membranes contain translocators that achieve protein translocation across and/or insertion into the membranes. Recent evidence has shown that mitochondrial beta-barrel protein assembly in the outer membrane requires specific translocator proteins in addition to the components of the general translocator complex in the outer membrane, the TOM40 complex. Here we report two novel mitochondrial outer membrane proteins in yeast, Tom13 and Tom38/Sam35, that mediate assembly of mitochondrial beta-barrel proteins, Tom40, and/or porin in the outer membrane. Depletion of Tom13 or Tom38/Sam35 affects assembly pathways of the beta-barrel proteins differently, suggesting that they mediate different steps of the complex assembly processes of beta-barrel proteins in the outer membrane. 相似文献
18.
F1F0 ATP synthase subunit c is a substrate of the novel YidC pathway for membrane protein biogenesis
van der Laan M Bechtluft P Kol S Nouwen N Driessen AJ 《The Journal of cell biology》2004,165(2):213-222
The Escherichia coli YidC protein belongs to the Oxa1 family of membrane proteins that have been suggested to facilitate the insertion and assembly of membrane proteins either in cooperation with the Sec translocase or as a separate entity. Recently, we have shown that depletion of YidC causes a specific defect in the functional assembly of F1F0 ATP synthase and cytochrome o oxidase. We now demonstrate that the insertion of in vitro-synthesized F1F0 ATP synthase subunit c (F0c) into inner membrane vesicles requires YidC. Insertion is independent of the proton motive force, and proteoliposomes containing only YidC catalyze the membrane insertion of F0c in its native transmembrane topology whereupon it assembles into large oligomers. Co-reconstituted SecYEG has no significant effect on the insertion efficiency. Remarkably, signal recognition particle and its membrane-bound receptor FtsY are not required for the membrane insertion of F0c. In conclusion, a novel membrane protein insertion pathway in E. coli is described in which YidC plays an exclusive role. 相似文献
19.
20.
Wiley SE Paddock ML Abresch EC Gross L van der Geer P Nechushtai R Murphy AN Jennings PA Dixon JE 《The Journal of biological chemistry》2007,282(33):23745-23749
The outer mitochondrial membrane protein mitoNEET was discovered as a binding target of pioglitazone, an insulin-sensitizing drug of the thiazolidinedione class used to treat type 2 diabetes (Colca, J. R., McDonald, W. G., Waldon, D. J., Leone, J. W., Lull, J. M., Bannow, C. A., Lund, E. T., and Mathews, W. R. (2004) Am. J. Physiol. 286, E252-E260). We have shown that mitoNEET is a member of a small family of proteins containing a 39-amino-acid CDGSH domain. Although the CDGSH domain is annotated as a zinc finger motif, mitoNEET was shown to contain iron (Wiley, S. E., Murphy, A. N., Ross, S. A., van der Geer, P., and Dixon, J. E. (2007) Proc. Natl. Acad. Sci. U. S. A. 104, 5318-5323). Optical and electron paramagnetic resonance spectroscopy showed that it contained a redox-active pH-labile Fe-S cluster. Mass spectrometry showed the loss of 2Fe and 2S upon cofactor extrusion. Spectroscopic studies of recombinant proteins showed that the 2Fe-2S cluster was coordinated by Cys-3 and His-1. The His ligand was shown to be involved in the observed pH lability of the cluster, indicating that loss of this ligand via protonation triggered release of the cluster. mitoNEET is the first identified 2Fe-2S-containing protein located in the outer mitochondrial membrane. Based on the biophysical data and domain fusion analysis, mitoNEET may function in Fe-S cluster shuttling and/or in redox reactions. 相似文献