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Idyahia A, Redouan S, Amalou G, Charoute H, Harmak H, Bonnet C, Petit C, Benrahma H, Barakat A. Exome sequencing reveals pathogenic mutations in the LARS2 and HSD17B4 genes associated with Perrault syndrome and D-bifunctional protein deficiency in Moroccan families. Mol Biol Rep 2024; 51:850. [PMID: 39052101 DOI: 10.1007/s11033-024-09740-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2024] [Accepted: 06/19/2024] [Indexed: 07/27/2024]
Abstract
BACKGROUND Syndromic hearing loss (SHL) is characterized by hearing impairment accompanied by other clinical manifestations, reaching over 400 syndromes. Early and accurate diagnosis is essential to understand the progression of hearing loss and associated systemic complications. METHODS AND RESULTS In this study, we investigated the genetic etiology of sensorineural hearing loss in three Moroccan patients using whole exome sequencing (WES). The results revealed in two families Perrault syndrome caused by LARS2, p. Asn153His; p. Thr629Met compound heterozygous variants in two siblings in one family; and p. Thr522Asn, a homozygous variant in two sisters in another. The patient in the third family was diagnosed with D-bifunctional protein deficiency (D-BPD), linked to compound heterozygous mutations p. Asn457Tyr and p. Val643Argfs*5 in HSD17B4. Molecular dynamic simulation results showed that Val643Argfs*5 does not prevent HSD17B4 protein from binding to the PEX5 receptor, but further studies are recommended to verify its effect on HSD17B4 protein functionality. CONCLUSION These results highlight the effectiveness of WES in identifying pathogenic mutations involved in heterogeneous disorders and the usefulness of bioinformatics in predicting their effects on protein structure.
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Affiliation(s)
- Assia Idyahia
- Genomics and Human Genetics Laboratory, Institut Pasteur du Maroc, 1 Place Louis Pasteur, Casablanca, 20360, Morocco
- Interdisciplinary Laboratory of Biotechnology and Health, Mohammed VI Higher Institute of Biosciences and Biotechnology, Mohammed VI University of Health Sciences (UM6SS), Casablanca, Morocco
| | - Salaheddine Redouan
- Genomics and Human Genetics Laboratory, Institut Pasteur du Maroc, 1 Place Louis Pasteur, Casablanca, 20360, Morocco
| | - Ghita Amalou
- Genomics and Human Genetics Laboratory, Institut Pasteur du Maroc, 1 Place Louis Pasteur, Casablanca, 20360, Morocco
| | - Hicham Charoute
- Research unit of epidemiology, biostatistics and bioinformatics, Institut Pasteur du Maroc, Casablanca, Morocco
| | - Houda Harmak
- Genomics and Human Genetics Laboratory, Institut Pasteur du Maroc, 1 Place Louis Pasteur, Casablanca, 20360, Morocco
| | - Crystel Bonnet
- Université Paris Cité, Institut Pasteur, AP-HP, Inserm, Fondation pour l'Audition, Institut de l'Audition, IHU reConnect, Paris, F-75012, France
| | - Christine Petit
- Université Paris Cité, Institut Pasteur, AP-HP, Inserm, Fondation pour l'Audition, Institut de l'Audition, IHU reConnect, Paris, F-75012, France
- Collège de France, Paris, F-75005, France
| | - Houda Benrahma
- Interdisciplinary Laboratory of Biotechnology and Health, Mohammed VI Higher Institute of Biosciences and Biotechnology, Mohammed VI University of Health Sciences (UM6SS), Casablanca, Morocco
| | - Abdelhamid Barakat
- Genomics and Human Genetics Laboratory, Institut Pasteur du Maroc, 1 Place Louis Pasteur, Casablanca, 20360, Morocco.
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Lansing H, Doering L, Fischer K, Baune MC, Schaewen AV. Analysis of potential redundancy among Arabidopsis 6-phosphogluconolactonase isoforms in peroxisomes. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:823-836. [PMID: 31641750 DOI: 10.1093/jxb/erz473] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Accepted: 10/10/2019] [Indexed: 05/21/2023]
Abstract
Recent work revealed that PGD2, an Arabidopsis 6-phosphogluconate dehydrogenase (6-PGD) catalysing the third step of the oxidative pentose-phosphate pathway (OPPP) in peroxisomes, is essential during fertilization. Earlier studies on the second step, catalysed by PGL3, a dually targeted Arabidopsis 6-phosphogluconolactonase (6-PGL), reported the importance of OPPP reactions in plastids but their irrelevance in peroxisomes. Assuming redundancy of 6-PGL activity in peroxisomes, we examined the sequences of other higher plant enzymes. In tomato, there exist two 6-PGL isoforms with the strong PTS1 motif SKL. However, their analysis revealed problems regarding peroxisomal targeting: reporter-PGL detection in peroxisomes required construct modification, which was also applied to the Arabidopsis isoforms. The relative contribution of PGL3 versus PGL5 during fertilization was assessed by mutant crosses. Reduced transmission ratios were found for pgl3-1 (T-DNA-eliminated PTS1) and also for knock-out allele pgl5-2. The prominent role of PGL3 showed as compromised growth of pgl3-1 seedlings on sucrose and higher activity of mutant PGL3-1 versus PGL5 using purified recombinant proteins. Evidence for PTS1-independent uptake was found for PGL3-1 and other Arabidopsis PGL isoforms, indicating that peroxisome import may be supported by a piggybacking mechanism. Thus, multiple redundancy at the level of the second OPPP step in peroxisomes explains the occurrence of pgl3-1 mutant plants.
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Affiliation(s)
- Hannes Lansing
- Molekulare Physiologie der Pflanzen, Institut für Biologie und Biotechnologie der Pflanzen, Westfälische Wilhelms-Universität Münster, Schlossplatz 7, D-48149 Münster, Germany
| | - Lennart Doering
- Molekulare Physiologie der Pflanzen, Institut für Biologie und Biotechnologie der Pflanzen, Westfälische Wilhelms-Universität Münster, Schlossplatz 7, D-48149 Münster, Germany
| | - Kerstin Fischer
- Molekulare Physiologie der Pflanzen, Institut für Biologie und Biotechnologie der Pflanzen, Westfälische Wilhelms-Universität Münster, Schlossplatz 7, D-48149 Münster, Germany
| | - Marie-Christin Baune
- Molekulare Physiologie der Pflanzen, Institut für Biologie und Biotechnologie der Pflanzen, Westfälische Wilhelms-Universität Münster, Schlossplatz 7, D-48149 Münster, Germany
| | - Antje Von Schaewen
- Molekulare Physiologie der Pflanzen, Institut für Biologie und Biotechnologie der Pflanzen, Westfälische Wilhelms-Universität Münster, Schlossplatz 7, D-48149 Münster, Germany
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Davis A, Abbriano R, Smith SR, Hildebrand M. Clarification of Photorespiratory Processes and the Role of Malic Enzyme in Diatoms. Protist 2016; 168:134-153. [PMID: 28104538 DOI: 10.1016/j.protis.2016.10.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 10/03/2016] [Accepted: 10/08/2016] [Indexed: 11/20/2022]
Abstract
Evidence suggests that diatom photorespiratory metabolism is distinct from other photosynthetic eukaryotes in that there may be at least two routes for the metabolism of the photorespiratory metabolite glycolate. One occurs primarily in the mitochondria and is similar to the C2 photorespiratory pathway, and the other processes glycolate through the peroxisomal glyoxylate cycle. Genomic analysis has identified the presence of key genes required for glycolate oxidation, the glyoxylate cycle, and malate metabolism, however, predictions of intracellular localization can be ambiguous and require verification. This knowledge gap leads to uncertainties surrounding how these individual pathways operate, either together or independently, to process photorespiratory intermediates under different environmental conditions. Here, we combine in silico sequence analysis, in vivo protein localization techniques and gene expression patterns to investigate key enzymes potentially involved in photorespiratory metabolism in the model diatom Thalassiosira pseudonana. We demonstrate the peroxisomal localization of isocitrate lyase and the mitochondrial localization of malic enzyme and a glycolate oxidase. Based on these analyses, we propose an updated model for photorespiratory metabolism in T. pseudonana, as well as a mechanism by which C2 photorespiratory metabolism and its associated pathways may operate during silicon starvation and growth arrest.
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Affiliation(s)
- Aubrey Davis
- Marine Biology Research Division, Scripps Institution of Oceanography, UC San Diego, La Jolla, CA, U.S.A
| | - Raffaela Abbriano
- Marine Biology Research Division, Scripps Institution of Oceanography, UC San Diego, La Jolla, CA, U.S.A
| | - Sarah R Smith
- Integrative Oceanography Division, Scripps Institution of Oceanography, UC San Diego, La Jolla, CA, U.S.A.; J. Craig Venter Institute, La Jolla, CA, U.S.A
| | - Mark Hildebrand
- Marine Biology Research Division, Scripps Institution of Oceanography, UC San Diego, La Jolla, CA, U.S.A..
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Abstract
Peroxisomes are remarkably versatile cell organelles whose size, shape, number, and protein content can vary greatly depending on the organism, the developmental stage of the organism’s life cycle, and the environment in which the organism lives. The main functions usually associated with peroxisomes include the metabolism of lipids and reactive oxygen species. However, in recent years, it has become clear that these organelles may also act as intracellular signaling platforms that mediate developmental decisions by modulating extraperoxisomal concentrations of several second messengers. To fulfill their functions, peroxisomes physically and functionally interact with other cell organelles, including mitochondria and the endoplasmic reticulum. Defects in peroxisome dynamics can lead to organelle dysfunction and have been associated with various human disorders. The purpose of this paper is to thoroughly summarize and discuss the current concepts underlying peroxisome formation, multiplication, and degradation. In addition, this paper will briefly highlight what is known about the interplay between peroxisomes and other cell organelles and explore the physiological and pathological implications of this interorganellar crosstalk.
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Affiliation(s)
- Marc Fransen
- Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, P.O. Box 601, 3000 Leuven, Belgium
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Rucktäschel R, Girzalsky W, Erdmann R. Protein import machineries of peroxisomes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2010; 1808:892-900. [PMID: 20659419 DOI: 10.1016/j.bbamem.2010.07.020] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Revised: 07/19/2010] [Accepted: 07/20/2010] [Indexed: 10/19/2022]
Abstract
Peroxisomes are a class of structurally and functionally related organelles present in almost all eukaryotic cells. The importance of peroxisomes for human life is highlighted by severe inherited diseases which are caused by defects of peroxins, encoded by PEX genes. To date 32 peroxins are known to be involved in different aspects of peroxisome biogenesis. This review addresses two of these aspects, the translocation of soluble proteins into the peroxisomal matrix and the biogenesis of the peroxisomal membrane. This article is part of a Special Issue entitled Protein translocation across or insertion into membranes.
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Affiliation(s)
- Robert Rucktäschel
- Abteilung für Systembiochemie, Institut für Physiologische Chemie, Medizinische Fakultät der Ruhr-Universität Bochum, D-44780 Bochum, Germany
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Girzalsky W, Saffian D, Erdmann R. Peroxisomal protein translocation. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2010; 1803:724-31. [DOI: 10.1016/j.bbamcr.2010.01.002] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2009] [Revised: 12/22/2009] [Accepted: 01/04/2010] [Indexed: 11/30/2022]
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Galland N, de Walque S, Voncken FGJ, Verlinde CLMJ, Michels PAM. An internal sequence targets Trypanosoma brucei triosephosphate isomerase to glycosomes. Mol Biochem Parasitol 2010; 171:45-9. [PMID: 20138091 DOI: 10.1016/j.molbiopara.2010.01.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2009] [Revised: 01/08/2010] [Accepted: 01/18/2010] [Indexed: 12/01/2022]
Abstract
In kinetoplastid protists, glycolysis is compartmentalized in glycosomes, organelles belonging to the peroxisome family. The Trypanosoma brucei glycosomal enzyme triosephosphate isomerase (TPI) does not contain either of the two established peroxisome-targeting signals, but we identified a 22 amino acids long fragment, present at an internal position of the polypeptide, that has the capacity to route a reporter protein to glycosomes in transfected trypanosomes, as demonstrated by cell-fractionation experiments and corroborating immunofluorescence studies. This polypeptide-internal routing information seems to be unique for the sequence of the trypanosome enzyme: a reporter protein fused to a Saccharomyces cerevisiae peptide containing the sequence corresponding to the 22-residue fragment of the T. brucei enzyme, was not targeted to glycosomes. In yeasts, as in most other organisms, TPI is indeed exclusively present in the cytosol. These results suggest that it may be possible to develop new trypanocidal drugs by targeting specifically the glycosome import mechanism of TPI.
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Affiliation(s)
- Nathalie Galland
- Research Unit for Tropical Diseases, de Duve Institute and Laboratory of Biochemistry, Université catholique de Louvain, TROP 74.39, Avenue Hippocrate 74, B-1200 Brussels, Belgium
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Piekarska K, Hardy G, Mol E, van den Burg J, Strijbis K, van Roermund C, van den Berg M, Distel B. The activity of the glyoxylate cycle in peroxisomes of Candida albicans depends on a functional β-oxidation pathway: evidence for reduced metabolite transport across the peroxisomal membrane. Microbiology (Reading) 2008; 154:3061-3072. [DOI: 10.1099/mic.0.2008/020289-0] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Katarzyna Piekarska
- Department of Medical Biochemistry, Academic Medical Center, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
| | - Guy Hardy
- Department of Medical Biochemistry, Academic Medical Center, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
| | - Els Mol
- Department of Medical Biochemistry, Academic Medical Center, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
| | - Janny van den Burg
- Department of Medical Biochemistry, Academic Medical Center, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
| | - Karin Strijbis
- Department of Medical Biochemistry, Academic Medical Center, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
| | - Carlo van Roermund
- Department of Genetic Metabolic Diseases, Academic Medical Center, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
| | - Marlene van den Berg
- Department of Medical Biochemistry, Academic Medical Center, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
| | - Ben Distel
- Department of Medical Biochemistry, Academic Medical Center, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
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9
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van der Klei IJ, Veenhuis M. PTS1-independent sorting of peroxisomal matrix proteins by Pex5p. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2007; 1763:1794-800. [PMID: 17005270 DOI: 10.1016/j.bbamcr.2006.08.013] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2006] [Revised: 07/27/2006] [Accepted: 08/18/2006] [Indexed: 10/24/2022]
Abstract
Most peroxisomal matrix proteins contain a peroxisomal targeting signal 1 (PTS1) for sorting to the correct organelle. This signal is located at the extreme C-terminus and generally consists of only three amino acids. The PTS1 is recognized by the receptor protein Pex5p. Several examples have been reported of peroxisomal matrix proteins that are sorted to peroxisomes via Pex5p, but lack a typical PTS1 tripeptide. In this contribution we present an overview of these so-called non-PTS1 proteins and discuss the current knowledge of the molecular mechanisms involved in their sorting.
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Affiliation(s)
- Ida J van der Klei
- Eukaryotic Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, The Netherlands.
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10
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Stanley WA, Filipp FV, Kursula P, Schüller N, Erdmann R, Schliebs W, Sattler M, Wilmanns M. Recognition of a functional peroxisome type 1 target by the dynamic import receptor pex5p. Mol Cell 2007; 24:653-663. [PMID: 17157249 PMCID: PMC5030714 DOI: 10.1016/j.molcel.2006.10.024] [Citation(s) in RCA: 120] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2006] [Revised: 08/16/2006] [Accepted: 10/16/2006] [Indexed: 10/23/2022]
Abstract
Peroxisomes require the translocation of folded and functional target proteins of various sizes across the peroxisomal membrane. We have investigated the structure and function of the principal import receptor Pex5p, which recognizes targets bearing a C-terminal peroxisomal targeting signal type 1. Crystal structures of the receptor in the presence and absence of a peroxisomal target, sterol carrier protein 2, reveal major structural changes from an open, snail-like conformation into a closed, circular conformation. These changes are caused by a long loop C terminal to the 7-fold tetratricopeptide repeat segments. Mutations in residues of this loop lead to defects in peroxisomal import in human fibroblasts. The structure of the receptor/cargo complex demonstrates that the primary receptor-binding site of the cargo is structurally and topologically autonomous, enabling the cargo to retain its native structure and function.
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Affiliation(s)
- Will A Stanley
- European Molecular Biology Laboratory-Hamburg Outstation, Notkestrasse 85, 22603 Hamburg
| | - Fabian V Filipp
- Structural and Computational Biology Unit, European Molecular Biology Laboratory-Heidelberg, Meyerhofstrasse 1, 69117 Heidelberg
| | - Petri Kursula
- European Molecular Biology Laboratory-Hamburg Outstation, Notkestrasse 85, 22603 Hamburg
| | - Nicole Schüller
- European Molecular Biology Laboratory-Hamburg Outstation, Notkestrasse 85, 22603 Hamburg
| | - Ralf Erdmann
- Department of Systems Biology, Institute for Physiological Chemistry, Faculty of Medicine, Ruhr University of Bochum, 44780 Bochum, Germany
| | - Wolfgang Schliebs
- Department of Systems Biology, Institute for Physiological Chemistry, Faculty of Medicine, Ruhr University of Bochum, 44780 Bochum, Germany
| | - Michael Sattler
- Structural and Computational Biology Unit, European Molecular Biology Laboratory-Heidelberg, Meyerhofstrasse 1, 69117 Heidelberg
| | - Matthias Wilmanns
- European Molecular Biology Laboratory-Hamburg Outstation, Notkestrasse 85, 22603 Hamburg.
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Stanley WA, Wilmanns M. Dynamic architecture of the peroxisomal import receptor Pex5p. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2006; 1763:1592-8. [PMID: 17141887 DOI: 10.1016/j.bbamcr.2006.10.015] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2006] [Revised: 10/26/2006] [Accepted: 10/26/2006] [Indexed: 11/29/2022]
Abstract
The majority of peroxisomal matrix proteins are recognized by the import receptor Pex5p. The receptor is dynamic in terms of its overall architecture and association with the peroxisomal membrane. It participates in different protein complexes during the translocation of cargos from the cytosol to the peroxisomal matrix. Its sequence comprises two structurally and functionally autonomous parts. The N-terminal segment interacts with several peroxins that assemble into distinct protein complexes during cargo translocation. Despite evidence for alpha-helical binding motifs for some of these components (Pex13p, Pex14p) its overall appearance is that of a molten globule and folding/unfolding transitions may play a critical role in its function. In contrast, most of the C-terminal part of the receptor folds into a ring-like alpha-helical structure and binds folded and functionally intact peroxisomal targets that bear a C-terminal peroxisomal targeting signal type-1. Some of these targets also bind to secondary binding sites of the receptor.
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Affiliation(s)
- Will A Stanley
- EMBL-Hamburg Outstation, c/o DESY, Notkestrasse 85, 22603 Hamburg, Germany
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Kerssen D, Hambruch E, Klaas W, Platta HW, de Kruijff B, Erdmann R, Kunau WH, Schliebs W. Membrane Association of the Cycling Peroxisome Import Receptor Pex5p. J Biol Chem 2006; 281:27003-15. [PMID: 16849337 DOI: 10.1074/jbc.m509257200] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Peroxisomal proteins carrying a peroxisome targeting signal type 1 (PTS1) are recognized in the cytosol by the cycling import receptor Pex5p. The receptor-cargo complex docks at the peroxisomal membrane where it associates with multimeric protein complexes, referred to as the docking and RING finger complexes. Here we have identified regions within the Saccharomyces cerevisiae Pex5p sequence that interconnect the receptor-cargo complex with the docking complex. Site-directed mutagenesis of the conserved tryptophan residue within a reverse WXXXF motif abolished two-hybrid binding with the N-terminal half of Pex14p. In combination with an additional mutation introduced into the Pex13p-binding site, we generated a Pex5p mutant defective in a stable association not only with the docking complex but also with the RING finger peroxins at the membrane. Surprisingly, PTS1 proteins are still imported into peroxisomes in these mutant cells. Because these mutations had no significant effect on the membrane binding properties of Pex5p, we examined yeast and human Pex5p for intrinsic lipid binding activity. In vitro analyses demonstrated that both proteins have the potential to insert spontaneously into phospholipid membranes. Altogether, these data strongly suggest that a translocation-competent state of the PTS1 receptor enters the membrane via protein-lipid interactions before it tightly associates with other peroxins.
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Affiliation(s)
- Daniela Kerssen
- Institut für Physiologische Chemie, Abt. Systembiochemie, Ruhr-Universität Bochum, D-44780 Bochum, Germany
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Brocard C, Hartig A. Peroxisome targeting signal 1: is it really a simple tripeptide? BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2006; 1763:1565-73. [PMID: 17007944 DOI: 10.1016/j.bbamcr.2006.08.022] [Citation(s) in RCA: 213] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2006] [Revised: 08/10/2006] [Accepted: 08/18/2006] [Indexed: 10/24/2022]
Abstract
Originally, the peroxisomal targeting signal 1 (PTS1) was defined as a tripeptide at the C-terminus of proteins prone to be imported into the peroxisomal matrix. The corresponding receptor PEX5 initiates the translocation of proteins by identifying potential substrates via their C-termini and trapping PTS1s through remodeling of its TPR domain. Thorough studies on the interaction between PEX5 and PTS1 as well as sequence-analytic tools revealed the influence of amino acid residues further upstream of the ultimate tripeptide. Altogether, PTS1s should be defined as dodecamer sequences at the C-terminal ends of proteins. These sequences accommodate physical contacts with both the surface and the binding cavity of PEX5 and ensure accessibility of the extreme C-terminus. Knowledge-based approaches in applied Bioinformatics provide reliable tools to accurately predict the peroxisomal location of proteins not yet determined experimentally.
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Affiliation(s)
- Cécile Brocard
- Max F Perutz Laboratories, University of Vienna, Department of Biochemistry, Dr. Bohrgasse 9, 1030 Vienna, Austria.
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