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Wang R, Chen Y, Xu S, Wei E, He P, Wang Q, Zhang Y, Tang X, Shen Z. Ssn6 Interacts with Polar Tube Protein 2 and Transcriptional Repressor for RNA Polymerase II: Insight into Its Involvement in the Biological Process of Microsporidium Nosema bombycis. J Fungi (Basel) 2023; 9:990. [PMID: 37888246 PMCID: PMC10608102 DOI: 10.3390/jof9100990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 10/02/2023] [Accepted: 10/03/2023] [Indexed: 10/28/2023] Open
Abstract
Nosema bombycis is a representative species of Microsporidia, and is the pathogen that causes pebrine disease in silkworms. In the process of infection, the polar tube of N. bombycis is injected into the host cells. During proliferation, N. bombycis recruits the mitochondria of host cells. The general transcriptional corepressor Ssn6 contains six tetratricopeptide repeats (TPR) and undertakes various important functions. In this study, we isolated and characterized Nbssn6 of the microsporidium N. bombycis. The Nbssn6 gene contains a complete ORF of 1182 bp in length that encodes a 393 amino acid polypeptide. Indirect immunofluorescence assay showed that the Ssn6 protein was mainly distributed in the cytoplasm and nucleus at the proliferative phase of N. bombycis. We revealed the interaction of Nbssn6 with polar tube protein 2 (Nbptp2) and the transcriptional repressor for RNA polymerase II (Nbtrrp2) by Co-IP and yeast two-hybrid assays. Results from RNA interference further confirmed that the transcriptional level of Nbptp2 and Nbtrrp2 was regulated by Nbssn6. These results suggest that Nbssn6 impacts the infection and proliferation of N. bombycis via interacting with the polar tube protein and transcriptional repressor for RNA polymerase II.
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Affiliation(s)
- Runpeng Wang
- College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China; (R.W.); (Y.C.); (S.X.); (E.W.); (P.H.); (Q.W.); (Y.Z.); (X.T.)
| | - Yong Chen
- College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China; (R.W.); (Y.C.); (S.X.); (E.W.); (P.H.); (Q.W.); (Y.Z.); (X.T.)
| | - Sheng Xu
- College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China; (R.W.); (Y.C.); (S.X.); (E.W.); (P.H.); (Q.W.); (Y.Z.); (X.T.)
| | - Erjun Wei
- College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China; (R.W.); (Y.C.); (S.X.); (E.W.); (P.H.); (Q.W.); (Y.Z.); (X.T.)
| | - Ping He
- College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China; (R.W.); (Y.C.); (S.X.); (E.W.); (P.H.); (Q.W.); (Y.Z.); (X.T.)
| | - Qiang Wang
- College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China; (R.W.); (Y.C.); (S.X.); (E.W.); (P.H.); (Q.W.); (Y.Z.); (X.T.)
- Sericulture Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang 212100, China
| | - Yiling Zhang
- College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China; (R.W.); (Y.C.); (S.X.); (E.W.); (P.H.); (Q.W.); (Y.Z.); (X.T.)
- Sericulture Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang 212100, China
| | - Xudong Tang
- College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China; (R.W.); (Y.C.); (S.X.); (E.W.); (P.H.); (Q.W.); (Y.Z.); (X.T.)
- Sericulture Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang 212100, China
| | - Zhongyuan Shen
- College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China; (R.W.); (Y.C.); (S.X.); (E.W.); (P.H.); (Q.W.); (Y.Z.); (X.T.)
- Sericulture Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang 212100, China
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2
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Zhang Y, Peng Y, Liu J, Yan J, Zhu K, Sun X, Bu X, Wang X, Ahammed GJ, Liu Y, Sun Z, Qi M, Wang F, Li T. Tetratricopeptide repeat protein SlREC2 positively regulates cold tolerance in tomato. PLANT PHYSIOLOGY 2023; 192:648-665. [PMID: 36760172 PMCID: PMC10152682 DOI: 10.1093/plphys/kiad085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 01/06/2023] [Accepted: 01/18/2023] [Indexed: 05/03/2023]
Abstract
Cold stress is a key environmental constraint that dramatically affects the growth, productivity, and quality of tomato (Solanum lycopersicum); however, the underlying molecular mechanisms of cold tolerance remain poorly understood. In this study, we identified REDUCED CHLOROPLAST COVERAGE 2 (SlREC2) encoding a tetratricopeptide repeat protein that positively regulates tomato cold tolerance. Disruption of SlREC2 largely reduced abscisic acid (ABA) levels, photoprotection, and the expression of C-REPEAT BINDING FACTOR (CBF)-pathway genes in tomato plants under cold stress. ABA deficiency in the notabilis (not) mutant, which carries a mutation in 9-CIS-EPOXYCAROTENOID DIOXYGENASE 1 (SlNCED1), strongly inhibited the cold tolerance of SlREC2-silenced plants and empty vector control plants and resulted in a similar phenotype. In addition, foliar application of ABA rescued the cold tolerance of SlREC2-silenced plants, which confirms that SlNCED1-mediated ABA accumulation is required for SlREC2-regulated cold tolerance. Strikingly, SlREC2 physically interacted with β-RING CAROTENE HYDROXYLASE 1b (SlBCH1b), a key regulatory enzyme in the xanthophyll cycle. Disruption of SlBCH1b severely impaired photoprotection, ABA accumulation, and CBF-pathway gene expression in tomato plants under cold stress. Taken together, this study reveals that SlREC2 interacts with SlBCH1b to enhance cold tolerance in tomato via integration of SlNCED1-mediated ABA accumulation, photoprotection, and the CBF-pathway, thus providing further genetic knowledge for breeding cold-resistant tomato varieties.
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Affiliation(s)
- Ying Zhang
- College of Horticulture, Shenyang Agricultural University, Shenyang 110866, China
| | - Yinxia Peng
- College of Horticulture, Shenyang Agricultural University, Shenyang 110866, China
| | - Juan Liu
- College of Horticulture, Shenyang Agricultural University, Shenyang 110866, China
| | - Jiarong Yan
- College of Horticulture, Shenyang Agricultural University, Shenyang 110866, China
| | - Kangyou Zhu
- College of Horticulture, Shenyang Agricultural University, Shenyang 110866, China
| | - Xin Sun
- College of Land and Environment, Shenyang Agricultural University, Shenyang 110866, China
| | - Xin Bu
- College of Horticulture, Shenyang Agricultural University, Shenyang 110866, China
| | - Xiujie Wang
- College of Horticulture, Shenyang Agricultural University, Shenyang 110866, China
| | - Golam Jalal Ahammed
- College of Horticulture and Plant Protection, Henan University of Science and Technology, Luoyang 471023, China
- Henan International Joint Laboratory of Stress Resistance Regulation and Safe Production of Protected Vegetables, Henan University of Science and Technology, Luoyang 471023, China
| | - Yufeng Liu
- College of Horticulture, Shenyang Agricultural University, Shenyang 110866, China
| | - Zhouping Sun
- College of Horticulture, Shenyang Agricultural University, Shenyang 110866, China
| | - Mingfang Qi
- College of Horticulture, Shenyang Agricultural University, Shenyang 110866, China
| | - Feng Wang
- College of Horticulture, Shenyang Agricultural University, Shenyang 110866, China
- National & Local Joint Engineering Research Center of Northern Horticultural Facilities Design & Application Technology (Liaoning), Shenyang 110866, China
- Key Laboratory of Protected Horticulture, Ministry of Education, Shenyang 110866, China
| | - Tianlai Li
- College of Horticulture, Shenyang Agricultural University, Shenyang 110866, China
- National & Local Joint Engineering Research Center of Northern Horticultural Facilities Design & Application Technology (Liaoning), Shenyang 110866, China
- Key Laboratory of Protected Horticulture, Ministry of Education, Shenyang 110866, China
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3
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Kreimendahl S, Rassow J. The Mitochondrial Outer Membrane Protein Tom70-Mediator in Protein Traffic, Membrane Contact Sites and Innate Immunity. Int J Mol Sci 2020; 21:E7262. [PMID: 33019591 PMCID: PMC7583919 DOI: 10.3390/ijms21197262] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 09/25/2020] [Accepted: 09/28/2020] [Indexed: 02/08/2023] Open
Abstract
Tom70 is a versatile adaptor protein of 70 kDa anchored in the outer membrane of mitochondria in metazoa, fungi and amoeba. The tertiary structure was resolved for the Tom70 of yeast, showing 26 α-helices, most of them participating in the formation of 11 tetratricopeptide repeat (TPR) motifs. Tom70 serves as a docking site for cytosolic chaperone proteins and co-chaperones and is thereby involved in the uptake of newly synthesized chaperone-bound proteins in mitochondrial biogenesis. In yeast, Tom70 additionally mediates ER-mitochondria contacts via binding to sterol transporter Lam6/Ltc1. In mammalian cells, TOM70 promotes endoplasmic reticulum (ER) to mitochondria Ca2+ transfer by association with the inositol-1,4,5-triphosphate receptor type 3 (IP3R3). TOM70 is specifically targeted by the Bcl-2-related protein MCL-1 that acts as an anti-apoptotic protein in macrophages infected by intracellular pathogens, but also in many cancer cells. By participating in the recruitment of PINK1 and the E3 ubiquitin ligase Parkin, TOM70 can be implicated in the development of Parkinson's disease. TOM70 acts as receptor of the mitochondrial antiviral-signaling protein (MAVS) and thereby participates in the corresponding system of innate immunity against viral infections. The protein encoded by Orf9b in the genome of SARS-CoV-2 binds to TOM70, probably compromising the synthesis of type I interferons.
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Affiliation(s)
| | - Joachim Rassow
- Institute for Biochemistry and Pathobiochemistry, Ruhr-University Bochum, 44801 Bochum, Germany;
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4
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Structural and Functional Heat Stress Responses of Chloroplasts of Arabidopsis thaliana. Genes (Basel) 2020; 11:genes11060650. [PMID: 32545654 PMCID: PMC7349189 DOI: 10.3390/genes11060650] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 06/04/2020] [Accepted: 06/08/2020] [Indexed: 11/17/2022] Open
Abstract
Temperature elevations constitute a major threat to plant performance. In recent years, much was learned about the general molecular mode of heat stress reaction of plants. The current research focuses on the integration of the knowledge into more global networks, including the reactions of cellular compartments. For instance, chloroplast function is central for plant growth and survival, and the performance of chloroplasts is tightly linked to the general status of the cell and vice versa. We examined the changes in photosynthesis, chloroplast morphology and proteomic composition posed in Arabidopsis thaliana chloroplasts after a single or repetitive heat stress treatment over a period of two weeks. We observed that the acclimation is potent in the case of repetitive application of heat stress, while a single stress results in lasting alterations. Moreover, the physiological capacity and its adjustment are dependent on the efficiency of the protein translocation process as judged from the analysis of mutants of the two receptor units of the chloroplast translocon, TOC64, and TOC33. In response to repetitive heat stress, plants without TOC33 accumulate Hsp70 proteins and plants without TOC64 have a higher content of proteins involved in thylakoid structure determination when compared to wild-type plants.
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5
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Bohne AV, Schwenkert S, Grimm B, Nickelsen J. Roles of Tetratricopeptide Repeat Proteins in Biogenesis of the Photosynthetic Apparatus. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2016; 324:187-227. [PMID: 27017009 DOI: 10.1016/bs.ircmb.2016.01.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Biosynthesis of the photosynthetic apparatus is a complex operation, which includes the concerted synthesis and assembly of lipids, pigments and metal cofactors, and dozens of proteins. Research conducted in recent years has shown that these processes, as well as the stabilization and repair of this molecular machinery, are facilitated by transiently acting regulatory proteins, many of which belong to the superfamily of helical repeat proteins. Here, we focus on one of its families in photoautotrophic model organisms, the tetratricopeptide repeat (TPR) proteins, which participate in almost all of these steps and are crucial for biogenesis of the thylakoid membrane.
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Affiliation(s)
- A-V Bohne
- Molecular Plant Sciences, Ludwig-Maximilians-University, Munich, Germany
| | - S Schwenkert
- Botany, Ludwig-Maximilians-University, Munich, Germany
| | - B Grimm
- Institute of Biology/Plant Physiology, Humboldt University, Berlin, Germany
| | - J Nickelsen
- Molecular Plant Sciences, Ludwig-Maximilians-University, Munich, Germany.
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6
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The Design and Structure of Outer Membrane Receptors from Peroxisomes, Mitochondria, and Chloroplasts. Structure 2015; 23:1783-1800. [DOI: 10.1016/j.str.2015.08.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 07/20/2015] [Accepted: 08/10/2015] [Indexed: 01/03/2023]
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7
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Paila YD, Richardson LGL, Schnell DJ. New insights into the mechanism of chloroplast protein import and its integration with protein quality control, organelle biogenesis and development. J Mol Biol 2014; 427:1038-1060. [PMID: 25174336 DOI: 10.1016/j.jmb.2014.08.016] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 08/20/2014] [Accepted: 08/23/2014] [Indexed: 01/04/2023]
Abstract
The translocons at the outer (TOC) and the inner (TIC) envelope membranes of chloroplasts mediate the targeting and import of several thousand nucleus-encoded preproteins that are required for organelle biogenesis and homeostasis. The cytosolic events in preprotein targeting remain largely unknown, although cytoplasmic chaperones have been proposed to facilitate delivery to the TOC complex. Preprotein recognition is mediated by the TOC GTPase receptors Toc159 and Toc34. The receptors constitute a GTP-regulated switch, which initiates membrane translocation via Toc75, a member of the Omp85 (outer membrane protein 85)/TpsB (two-partner secretion system B) family of bacterial, plastid and mitochondrial β-barrel outer membrane proteins. The TOC receptor systems have diversified to recognize distinct sets of preproteins, thereby maximizing the efficiency of targeting in response to changes in gene expression during developmental and physiological events that impact organelle function. The TOC complex interacts with the TIC translocon to allow simultaneous translocation of preproteins across the envelope. Both the two inner membrane complexes, the Tic110 and 1 MDa complexes, have been implicated as constituents of the TIC translocon, and it remains to be determined how they interact to form the TIC channel and assemble the import-associated chaperone network in the stroma that drives import across the envelope membranes. This review will focus on recent developments in our understanding of the mechanisms and diversity of the TOC-TIC systems. Our goal is to incorporate these recent studies with previous work and present updated or revised models for the function of TOC-TIC in protein import.
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Affiliation(s)
- Yamuna D Paila
- Department of Biochemistry and Molecular Biology, Life Sciences Laboratories Room N431, 240 Thatcher Rd, University of Massachusetts, Amherst MA 01003-9364, USA
| | - Lynn G L Richardson
- Department of Biochemistry and Molecular Biology, Life Sciences Laboratories Room N431, 240 Thatcher Rd, University of Massachusetts, Amherst MA 01003-9364, USA
| | - Danny J Schnell
- Department of Biochemistry and Molecular Biology, Life Sciences Laboratories Room N431, 240 Thatcher Rd, University of Massachusetts, Amherst MA 01003-9364, USA
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8
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Sommer MS, Schleiff E. Protein targeting and transport as a necessary consequence of increased cellular complexity. Cold Spring Harb Perspect Biol 2014; 6:6/8/a016055. [PMID: 25085907 DOI: 10.1101/cshperspect.a016055] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
With increasing intracellular complexity, a new cell-biological problem that is the allocation of cytoplasmically synthesized proteins to their final destinations within the cell emerged. A special challenge is thereby the translocation of proteins into or across cellular membranes. The underlying mechanisms are only in parts well understood, but it can be assumed that the course of cellular evolution had a deep impact on the design of the required molecular machines. In this article, we aim to summarize the current knowledge and concepts of the evolutionary development of protein trafficking as a necessary premise and consequence of increased cellular complexity.
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Affiliation(s)
- Maik S Sommer
- Institute for Molecular Biosciences, Department of Biosciences, Molecular Cell Biology of Plants, Goethe University Frankfurt am Main, D-60438 Frankfurt, Germany
| | - Enrico Schleiff
- Institute for Molecular Biosciences, Department of Biosciences, Molecular Cell Biology of Plants, Goethe University Frankfurt am Main, D-60438 Frankfurt, Germany Cluster of Excellence Macromolecular Complexes, Goethe University Frankfurt am Main, D-60438 Frankfurt, Germany Centre of Membrane Proteomics, Goethe University Frankfurt am Main, D-60438 Frankfurt, Germany
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9
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Panigrahi R, Whelan J, Vrielink A. Exploring ligand recognition, selectivity and dynamics of TPR domains of chloroplast Toc64 and mitochondria Om64 fromArabidopsis thaliana. J Mol Recognit 2014; 27:402-14. [DOI: 10.1002/jmr.2360] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2013] [Revised: 01/14/2014] [Accepted: 01/15/2014] [Indexed: 01/31/2023]
Affiliation(s)
- Rashmi Panigrahi
- School of Chemistry and Biochemistry; University of Western Australia; 35 Stirling Highway Crawley WA 6009 Australia
| | - James Whelan
- ARC Centre of Excellence in Plant Energy Biology; University of Western Australia; 35 Stirling Highway Crawley WA 6009 Australia
- Department of Botany, School of Life Science; La Trobe University; Bundoora Victoria 3086 Australia
| | - Alice Vrielink
- School of Chemistry and Biochemistry; University of Western Australia; 35 Stirling Highway Crawley WA 6009 Australia
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10
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Hu Z, Xu F, Guan L, Qian P, Liu Y, Zhang H, Huang Y, Hou S. The tetratricopeptide repeat-containing protein slow green1 is required for chloroplast development in Arabidopsis. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:1111-23. [PMID: 24420572 PMCID: PMC3935568 DOI: 10.1093/jxb/ert463] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
A new gene, SG1, was identified in a slow-greening mutant (sg1) isolated from an ethylmethanesulphonate-mutagenized population of Arabidopsis thaliana. The newly formed leaves of sg1 were initially albino, but gradually became pale green. After 3 weeks, the leaves of the mutant were as green as those of the wild-type plants. Transmission electron microscopic observations revealed that the mutant displayed delayed proplastid to chloroplast transition. The results of map-based cloning showed that SG1 encodes a chloroplast-localized tetratricopeptide repeat-containing protein. Quantitative real-time reverse transcription-PCR data demonstrated the presence of SG1 gene expression in all tissues, particularly young green tissues. The sg1 mutation disrupted the expression levels of several genes associated with chloroplast development, photosynthesis, and chlorophyll biosynthesis. The results of genetic analysis indicated that gun1 and gun4 partially restored the expression patterns of the previously detected chloroplast-associated genes, thereby ameliorating the slow-greening phenotype of sg1. Taken together, the results suggest that the newly identified protein, SG1, is required for chloroplast development in Arabidopsis.
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Affiliation(s)
- Zhihong Hu
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou 730000, PR China
- * These authors contributed equally to this work
| | - Fan Xu
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou 730000, PR China
- * These authors contributed equally to this work
| | - Liping Guan
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou 730000, PR China
| | - Pingping Qian
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou 730000, PR China
| | - Yaqiong Liu
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou 730000, PR China
| | - Huifang Zhang
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou 730000, PR China
| | - Yan Huang
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou 730000, PR China
| | - Suiwen Hou
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou 730000, PR China
- National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai 200032, PR China
- To whom correspondence should be addressed. E-mail:
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11
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Panigrahi R, Adina-Zada A, Whelan J, Vrielink A. Ligand recognition by the TPR domain of the import factor Toc64 from Arabidopsis thaliana. PLoS One 2013; 8:e83461. [PMID: 24391770 PMCID: PMC3877065 DOI: 10.1371/journal.pone.0083461] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 11/04/2013] [Indexed: 01/21/2023] Open
Abstract
The specific targeting of protein to organelles is achieved by targeting signals being recognised by their cognate receptors. Cytosolic chaperones, bound to precursor proteins, are recognized by specific receptors of the import machinery enabling transport into the specific organelle. The aim of this study was to gain greater insight into the mode of recognition of the C-termini of Hsp70 and Hsp90 chaperones by the Tetratricopeptide Repeat (TPR) domain of the chloroplast import receptor Toc64 from Arabidopsis thaliana (At). The monomeric TPR domain binds with 1∶1 stoichiometry in similar micromolar affinity to both Hsp70 and Hsp90 as determined by isothermal titration calorimetry (ITC). Mutations of the terminal EEVD motif caused a profound decrease in affinity. Additionally, this study considered the contributions of residues upstream as alanine scanning experiments of these residues showed reduced binding affinity. Molecular dynamics simulations of the TPR domain helices upon peptide binding predicted that two helices within the TPR domain move backwards, exposing the cradle surface for interaction with the peptide. Our findings from ITC and molecular dynamics studies suggest that AtToc64_TPR does not discriminate between C-termini peptides of Hsp70 and Hsp90.
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Affiliation(s)
- Rashmi Panigrahi
- School of Chemistry and Biochemistry, University of Western Australia, Crawley, Western Australia, Australia
| | - Abdussalam Adina-Zada
- School of Chemistry and Biochemistry, University of Western Australia, Crawley, Western Australia, Australia
| | - James Whelan
- ARC Centre of Excellence in Plant Energy Biology, University of Western Australia, Crawley, Western Australia, Australia
- Department of Botany, School of Life Science, La Trobe University, Bundoora, Victoria, Australia
| | - Alice Vrielink
- School of Chemistry and Biochemistry, University of Western Australia, Crawley, Western Australia, Australia
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12
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Shi LX, Theg SM. The chloroplast protein import system: from algae to trees. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1833:314-31. [PMID: 23063942 DOI: 10.1016/j.bbamcr.2012.10.002] [Citation(s) in RCA: 138] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Revised: 09/07/2012] [Accepted: 10/01/2012] [Indexed: 01/15/2023]
Abstract
Chloroplasts are essential organelles in the cells of plants and algae. The functions of these specialized plastids are largely dependent on the ~3000 proteins residing in the organelle. Although chloroplasts are capable of a limited amount of semiautonomous protein synthesis - their genomes encode ~100 proteins - they must import more than 95% of their proteins after synthesis in the cytosol. Imported proteins generally possess an N-terminal extension termed a transit peptide. The importing translocons are made up of two complexes in the outer and inner envelope membranes, the so-called Toc and Tic machineries, respectively. The Toc complex contains two precursor receptors, Toc159 and Toc34, a protein channel, Toc75, and a peripheral component, Toc64/OEP64. The Tic complex consists of as many as eight components, namely Tic22, Tic110, Tic40, Tic20, Tic21 Tic62, Tic55 and Tic32. This general Toc/Tic import pathway, worked out largely in pea chloroplasts, appears to operate in chloroplasts in all green plants, albeit with significant modifications. Sub-complexes of the Toc and Tic machineries are proposed to exist to satisfy different substrate-, tissue-, cell- and developmental requirements. In this review, we summarize our understanding of the functions of Toc and Tic components, comparing these components of the import machinery in green algae through trees. We emphasize recent findings that point to growing complexities of chloroplast protein import process, and use the evolutionary relationships between proteins of different species in an attempt to define the essential core translocon components and those more likely to be responsible for regulation. This article is part of a Special Issue entitled: Protein Import and Quality Control in Mitochondria and Plastids.
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Affiliation(s)
- Lan-Xin Shi
- Department of Plant Biology, University of California-Davis, One Shields Avenue, Davis, CA 95616, USA.
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13
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Zeytuni N, Zarivach R. Structural and functional discussion of the tetra-trico-peptide repeat, a protein interaction module. Structure 2012; 20:397-405. [PMID: 22404999 DOI: 10.1016/j.str.2012.01.006] [Citation(s) in RCA: 238] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2011] [Revised: 01/04/2012] [Accepted: 01/06/2012] [Indexed: 01/14/2023]
Abstract
Tetra-trico-peptide repeat (TPR) domains are found in numerous proteins, where they serve as interaction modules and multiprotein complex mediators. TPRs can be found in all kingdoms of life and regulate diverse biological processes, such as organelle targeting and protein import, vesicle fusion, and biomineralization. This review considers the structural features of TPR domains that permit the great ligand-binding diversity of this motif, given that TPR-interacting partners display variations in both sequence and secondary structure. In addition, tools for predicting TPR-interacting partners are discussed, as are the abilities of TPR domains to serve as protein-protein interaction scaffolds in biotechnology and therapeutics.
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Affiliation(s)
- Natalie Zeytuni
- Department of Life Sciences, Ben-Gurion University of the Negev and National Institute for Biotechnology in the Negev, P.O. Box 653, Beer Sheva 84105, Israel
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14
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Duncan O, Murcha MW, Whelan J. Unique components of the plant mitochondrial protein import apparatus. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1833:304-13. [PMID: 22406071 DOI: 10.1016/j.bbamcr.2012.02.015] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2012] [Revised: 02/21/2012] [Accepted: 02/23/2012] [Indexed: 10/28/2022]
Abstract
The basic mitochondrial protein import apparatus was established in the earliest eukaryotes. Over the subsequent course of evolution and the divergence of the plant, animal and fungal lineages, this basic import apparatus has been modified and expanded in order to meet the specific needs of protein import in each kingdom. In the plant kingdom, the arrival of the plastid complicated the process of protein trafficking and is thought to have given rise to the evolution of a number of unique components that allow specific and efficient targeting of mitochondrial proteins from their site of synthesis in the cytosol, to their final location in the organelle. This includes the evolution of two unique outer membrane import receptors, plant Translocase of outer membrane 20 kDa subunit (TOM20) and Outer membrane protein of 64 kDa (OM64), the loss of a receptor domain from an ancestral import component, Translocase of outer membrane 22 kDa subunit (TOM22), evolution of unique features in the disulfide relay system of the inter membrane space, and the addition of an extra membrane spanning domain to another ancestral component of the inner membrane, Translocase of inner membrane 17 kDa subunit (TIM17). Notably, many of these components are encoded by multi-gene families and exhibit differential sub-cellular localisation and functional specialisation. This article is part of a Special Issue entitled: Protein Import and Quality Control in Mitochondria and Plastids.
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Affiliation(s)
- Owen Duncan
- ARC Centre of Excellence in Plant Energy Biology, Bayliss Building M316, The University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009, Australia
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Self-recognition mechanism of MamA, a magnetosome-associated TPR-containing protein, promotes complex assembly. Proc Natl Acad Sci U S A 2011; 108:E480-7. [PMID: 21784982 DOI: 10.1073/pnas.1103367108] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The magnetosome, a biomineralizing organelle within magnetotactic bacteria, allows their navigation along geomagnetic fields. Magnetosomes are membrane-bound compartments containing magnetic nanoparticles and organized into a chain within the cell, the assembly and biomineralization of magnetosomes are controlled by magnetosome-associated proteins. Here, we describe the crystal structures of the magnetosome-associated protein, MamA, from Magnetospirillum magneticum AMB-1 and Magnetospirillum gryphiswaldense MSR-1. MamA folds as a sequential tetra-trico-peptide repeat (TPR) protein with a unique hook-like shape. Analysis of the MamA structures indicates two distinct domains that can undergo conformational changes. Furthermore, structural analysis of seven crystal forms verified that the core of MamA is not affected by crystallization conditions and identified three protein-protein interaction sites, namely a concave site, a convex site, and a putative TPR repeat. Additionally, relying on transmission electron microscopy and size exclusion chromatography, we show that highly stable complexes form upon MamA homooligomerization. Disruption of the MamA putative TPR motif or N-terminal domain led to protein mislocalization in vivo and prevented MamA oligomerization in vitro. We, therefore, propose that MamA self-assembles through its putative TPR motif and its concave site to create a large homooligomeric scaffold which can interact with other magnetosome-associated proteins via the MamA convex site. We discuss the structural basis for TPR homooligomerization that allows the proper function of a prokaryotic organelle.
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Bölter B, Soll J. Protein Import into Chloroplasts: Dealing with the (Membrane) Integration Problem. Chembiochem 2011; 12:1655-61. [DOI: 10.1002/cbic.201100118] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Indexed: 11/10/2022]
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Delage L, Leblanc C, Nyvall Collén P, Gschloessl B, Oudot MP, Sterck L, Poulain J, Aury JM, Cock JM. In silico survey of the mitochondrial protein uptake and maturation systems in the brown alga Ectocarpus siliculosus. PLoS One 2011; 6:e19540. [PMID: 21611166 PMCID: PMC3097184 DOI: 10.1371/journal.pone.0019540] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2010] [Accepted: 03/31/2011] [Indexed: 01/24/2023] Open
Abstract
The acquisition of mitochondria was a key event in eukaryote evolution. The aim of this study was to identify homologues of the components of the mitochondrial protein import machinery in the brown alga Ectocarpus and to use this information to investigate the evolutionary history of this fundamental cellular process. Detailed searches were carried out both for components of the protein import system and for related peptidases. Comparative and phylogenetic analyses were used to investigate the evolution of mitochondrial proteins during eukaryote diversification. Key observations include phylogenetic evidence for very ancient origins for many protein import components (Tim21, Tim50, for example) and indications of differences between the outer membrane receptors that recognize the mitochondrial targeting signals, suggesting replacement, rearrangement and/or emergence of new components across the major eukaryotic lineages. Overall, the mitochondrial protein import components analysed in this study confirmed a high level of conservation during evolution, indicating that most are derived from very ancient, ancestral proteins. Several of the protein import components identified in Ectocarpus, such as Tim21, Tim50 and metaxin, have also been found in other stramenopiles and this study suggests an early origin during the evolution of the eukaryotes.
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Affiliation(s)
- Ludovic Delage
- Université Pierre et Marie Curie, The Marine Plants and Biomolecules Laboratory, UMR 7139, Station Biologique de Roscoff, Roscoff, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7139, Laboratoire International Associé Dispersal and Adaptation in Marine Species, Station Biologique de Roscoff, Roscoff, France
| | - Catherine Leblanc
- Université Pierre et Marie Curie, The Marine Plants and Biomolecules Laboratory, UMR 7139, Station Biologique de Roscoff, Roscoff, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7139, Laboratoire International Associé Dispersal and Adaptation in Marine Species, Station Biologique de Roscoff, Roscoff, France
| | - Pi Nyvall Collén
- Université Pierre et Marie Curie, The Marine Plants and Biomolecules Laboratory, UMR 7139, Station Biologique de Roscoff, Roscoff, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7139, Laboratoire International Associé Dispersal and Adaptation in Marine Species, Station Biologique de Roscoff, Roscoff, France
| | - Bernhard Gschloessl
- Université Pierre et Marie Curie, The Marine Plants and Biomolecules Laboratory, UMR 7139, Station Biologique de Roscoff, Roscoff, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7139, Laboratoire International Associé Dispersal and Adaptation in Marine Species, Station Biologique de Roscoff, Roscoff, France
| | - Marie-Pierre Oudot
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
| | - Lieven Sterck
- VIB Department of Plant Systems Biology, Ghent University, Ghent, Belgium
| | - Julie Poulain
- Commissariat à l'Energie Atomique, Direction des Sciences du Vivant, Institut de Génomique, Génoscope, Evry, France
- Centre National de la Recherche Scientifique, UMR 8030, Evry, France
- Université d'Evry, Evry, France
| | - Jean-Marc Aury
- Commissariat à l'Energie Atomique, Direction des Sciences du Vivant, Institut de Génomique, Génoscope, Evry, France
- Centre National de la Recherche Scientifique, UMR 8030, Evry, France
- Université d'Evry, Evry, France
| | - J. Mark Cock
- Université Pierre et Marie Curie, The Marine Plants and Biomolecules Laboratory, UMR 7139, Station Biologique de Roscoff, Roscoff, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7139, Laboratoire International Associé Dispersal and Adaptation in Marine Species, Station Biologique de Roscoff, Roscoff, France
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Murakami MT, Sforça ML, Neves JL, Paiva JH, Domingues MN, Pereira ALA, Zeri ACDM, Benedetti CE. The repeat domain of the type III effector protein PthA shows a TPR-like structure and undergoes conformational changes upon DNA interaction. Proteins 2010; 78:3386-95. [PMID: 20848643 DOI: 10.1002/prot.22846] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2010] [Revised: 07/16/2010] [Accepted: 07/24/2010] [Indexed: 11/11/2022]
Abstract
Many plant pathogenic bacteria rely on effector proteins to suppress defense and manipulate host cell mechanisms to cause disease. The effector protein PthA modulates the host transcriptome to promote citrus canker. PthA possesses unusual protein architecture with an internal region encompassing variable numbers of near-identical tandem repeats of 34 amino acids termed the repeat domain. This domain mediates protein-protein and protein-DNA interactions, and two polymorphic residues in each repeat unit determine DNA specificity. To gain insights into how the repeat domain promotes protein-protein and protein-DNA contacts, we have solved the structure of a peptide corresponding to 1.5 units of the PthA repeat domain by nuclear magnetic resonance (NMR) and carried out small-angle X-ray scattering (SAXS) and spectroscopic studies on the entire 15.5-repeat domain of PthA2 (RD2). Consistent with secondary structure predictions and circular dichroism data, the NMR structure of the 1.5-repeat peptide reveals three α-helices connected by two turns that fold into a tetratricopeptide repeat (TPR)-like domain. The NMR structure corroborates the theoretical TPR superhelix predicted for RD2, which is also in agreement with the elongated shape of RD2 determined by SAXS. Furthermore, RD2 undergoes conformational changes in a pH-dependent manner and upon DNA interaction, and shows sequence similarities to pentatricopeptide repeat (PPR), a nucleic acid-binding motif structurally related to TPR. The results point to a model in which the RD2 structure changes its compactness as it embraces the DNA with the polymorphic diresidues facing the interior of the superhelix oriented toward the nucleotide bases.
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Affiliation(s)
- Mário Tyago Murakami
- Laboratório Nacional de Biociências, Centro Nacional de Pesquisa em Energia e Materiais, 13083-970, Campinas, SP, Brazil.
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Zeytuni N, Zarivach R. Crystallization and preliminary crystallographic analysis of the Magnetospirillum magneticum AMB-1 and M. gryphiswaldense MSR-1 magnetosome-associated proteins MamA. Acta Crystallogr Sect F Struct Biol Cryst Commun 2010; 66:824-7. [PMID: 20606283 PMCID: PMC2898471 DOI: 10.1107/s1744309110018300] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2010] [Accepted: 05/17/2010] [Indexed: 11/11/2022]
Abstract
MamA is a unique magnetosome-associated protein that is predicted to contain six sequential tetratricopeptide-repeat (TPR) motifs. The TPR structural motif serves as a template for protein-protein interactions and mediates the assembly of multi-protein complexes. Here, the crystallization and preliminary X-ray analysis of recombinant and purified Magnetospirillum magneticum and M. gryphiswaldense MamA are reported for the first time. M. gryphiswaldense MamADelta41 crystallized in the tetragonal space group P4(1)2(1)2 or P4(3)2(1)2, with unit-cell parameters a = b = 58.88, c = 144.09 A. M. magneticum MamADelta41 crystallized in the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 44.75, b = 76.19, c = 105.05 A. X-ray diffraction data were collected to resolutions of 2.0 and 1.95 A, respectively.
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Affiliation(s)
- Natalie Zeytuni
- Department of Life Sciences and National Institute for Biotechnology in the Negev, Ben Gurion University of the Negev, PO Box 653, Beer-Sheva 84105, Israel
| | - Raz Zarivach
- Department of Life Sciences and National Institute for Biotechnology in the Negev, Ben Gurion University of the Negev, PO Box 653, Beer-Sheva 84105, Israel
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Zeytuni N, Zarivach R. Purification of the M. magneticum strain AMB-1 magnetosome associated protein MamADelta41. J Vis Exp 2010:1844. [PMID: 20339346 DOI: 10.3791/1844] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Magnetotactic bacteria comprise a diverse group of aquatic microorganisms that are able to orientate themselves along geomagnetic fields. This behavior is believed to aid their search for suitable environments (1). This capability is conferred by the magnetosome, a subcellular organelle that consists of a linear-chain assembly of lipid vesicles each able to biomineralize and enclose a ~50-nm crystal of magnetite or greigite. A principle component of the magnetosome that was shown to be required for the formation of functional vesicles is MamA. MamA is a highly abundant magnetosome-associated protein which is one of the most characterized magnetosome-associated proteins in vivo (2-6). This article focuses on the purification of MamA, which despite being studied in vivo, no clear functional or structural details have been identified for it. Bioinformatics analysis suggested that MamA is a tetra-tricopeptide repeat (TPR) containing protein. TPR is a structural motif found as such or forming part of a bigger fold in a wide range of proteins, it serves as a template for protein-protein interactions and mediates multi-protein complexes (7). TPRs are involved in many crucial tasks in eukaryotic cell organelle processes and many bacterial pathways (8-14). In order to understand MamA, a unique TPR containing protein, highly purified protein is required as a first step. In this article, we present the purification protocol for a stable MamA deletion mutant (MamADelta41) from M. magneticum AMB-1.
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Affiliation(s)
- Natalie Zeytuni
- Department of Life Sciences and National Institute for Biotechnology in the Negev, Ben Gurion University of the Negev
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Protein import into chloroplasts: the Tic complex and its regulation. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2010; 1803:740-7. [PMID: 20100520 DOI: 10.1016/j.bbamcr.2010.01.015] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2009] [Revised: 01/11/2010] [Accepted: 01/13/2010] [Indexed: 11/24/2022]
Abstract
Chloroplasts like mitochondria were derived from an endosymbiontic event. Due to the massive gene transfer to the nucleus during endosymbiosis, only a limited number of chloroplastic proteins are still encoded for in the plastid genome. Most of the nuclear-encoded plastidic proteins are post-translationally translocated back to the chloroplast via the general import pathway through distinct outer and inner envelope membrane protein complexes, the Toc and Tic translocons (Translocon at the outer/inner envelope membrane of chloroplasts). Eight Tic subunits have been described so far, including two potential channel proteins (Tic110 and Tic20), the "motor complex" (Tic40 associated with the stromal chaperone Hsp93) and the "redox regulon" (Tic62, Tic55, and Tic32) involved in regulation of protein import via the metabolic redox status of the chloroplast. Regulation can additionally occur via thioredoxins (Tic110 and Tic55) or via the calcium/calmodulin network (Tic110 and Tic32). In this review we present the current knowledge about the Tic complex focusing on its regulation and addressing some still open questions.
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