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Zappa F, Intartaglia D, Guarino AM, De Cegli R, Wilson C, Salierno FG, Polishchuk E, Sorrentino NC, Conte I, De Matteis MA. Role of trafficking protein particle complex 2 in medaka development. Traffic 2024; 25:e12924. [PMID: 37963679 DOI: 10.1111/tra.12924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 10/16/2023] [Accepted: 10/27/2023] [Indexed: 11/16/2023]
Abstract
The skeletal dysplasia spondyloepiphyseal dysplasia tarda (SEDT) is caused by mutations in the TRAPPC2 gene, which encodes Sedlin, a component of the trafficking protein particle (TRAPP) complex that we have shown previously to be required for the export of type II collagen (Col2) from the endoplasmic reticulum. No vertebrate model for SEDT has been generated thus far. To address this gap, we generated a Sedlin knockout animal by mutating the orthologous TRAPPC2 gene (olSedl) of Oryzias latipes (medaka) fish. OlSedl deficiency leads to embryonic defects, short size, diminished skeletal ossification and altered Col2 production and secretion, resembling human defects observed in SEDT patients. Moreover, SEDT knock-out animals display photoreceptor degeneration and gut morphogenesis defects, suggesting a key role for Sedlin in the development of these organs. Thus, by studying Sedlin function in vivo, we provide evidence for a mechanistic link between TRAPPC2-mediated membrane trafficking, Col2 export, and developmental disorders.
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Affiliation(s)
- Francesca Zappa
- Telethon Institute of Genetics and Medicine, TIGEM, Pozzuoli (Naples), Italy
| | - Daniela Intartaglia
- Telethon Institute of Genetics and Medicine, TIGEM, Pozzuoli (Naples), Italy
| | - Andrea M Guarino
- Telethon Institute of Genetics and Medicine, TIGEM, Pozzuoli (Naples), Italy
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Naples, Italy
| | - Rossella De Cegli
- Telethon Institute of Genetics and Medicine, TIGEM, Pozzuoli (Naples), Italy
| | - Cathal Wilson
- Telethon Institute of Genetics and Medicine, TIGEM, Pozzuoli (Naples), Italy
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Naples, Italy
| | | | - Elena Polishchuk
- Telethon Institute of Genetics and Medicine, TIGEM, Pozzuoli (Naples), Italy
| | - Nicolina Cristina Sorrentino
- Telethon Institute of Genetics and Medicine, TIGEM, Pozzuoli (Naples), Italy
- Department of Clinical Medicine and Surgery, University of Naples Federico II, Naples, Italy
| | - Ivan Conte
- Telethon Institute of Genetics and Medicine, TIGEM, Pozzuoli (Naples), Italy
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Maria Antonietta De Matteis
- Telethon Institute of Genetics and Medicine, TIGEM, Pozzuoli (Naples), Italy
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Naples, Italy
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2
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Sacher M, Shahrzad N, Kamel H, Milev MP. TRAPPopathies: An emerging set of disorders linked to variations in the genes encoding transport protein particle (TRAPP)-associated proteins. Traffic 2018; 20:5-26. [PMID: 30152084 DOI: 10.1111/tra.12615] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 08/23/2018] [Accepted: 08/26/2018] [Indexed: 02/06/2023]
Abstract
The movement of proteins between cellular compartments requires the orchestrated actions of many factors including Rab family GTPases, Soluble NSF Attachment protein REceptors (SNAREs) and so-called tethering factors. One such tethering factor is called TRAnsport Protein Particle (TRAPP), and in humans, TRAPP proteins are distributed into two related complexes called TRAPP II and III. Although thought to act as a single unit within the complex, in the past few years it has become evident that some TRAPP proteins function independently of the complex. Consistent with this, variations in the genes encoding these proteins result in a spectrum of human diseases with diverse, but partially overlapping, phenotypes. This contrasts with other tethering factors such as COG, where variations in the genes that encode its subunits all result in an identical phenotype. In this review, we present an up-to-date summary of all the known disease-related variations of genes encoding TRAPP-associated proteins and the disorders linked to these variations which we now call TRAPPopathies.
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Affiliation(s)
- Michael Sacher
- Department of Biology, Concordia University, Montreal, Quebec, Canada.,Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada
| | - Nassim Shahrzad
- Department of Medicine, University of California, San Francisco, California
| | - Hiba Kamel
- Department of Biology, Concordia University, Montreal, Quebec, Canada
| | - Miroslav P Milev
- Department of Biology, Concordia University, Montreal, Quebec, Canada
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Kong L, Wang D, Li S, Zhang C, Jiang X, Guan Q, Zhang Z, Jing F, Xu J. Clinical Diagnosis of X-Linked Spondyloepiphyseal Dysplasia Tarda and a Novel Missense Mutation in the Sedlin Gene (SEDL). Int J Endocrinol 2018; 2018:8263136. [PMID: 30647738 PMCID: PMC6311833 DOI: 10.1155/2018/8263136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Revised: 10/04/2018] [Accepted: 10/25/2018] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVE Spondyloepiphyseal dysplasia tarda (SEDT) is a rare hereditary bone disease characterized by spinal and epiphyseal anomalies. We identified the disease by gene sequencing in a Chinese pedigree with SEDT. METHODS We extracted genomic DNA from five members of a four-generation Chinese SEDT kindred with three affected males and then analyzed the genetic mutation by PCR and DNA sequencing. RESULTS DNA sequencing showed that the genetic missense mutation occurred one bp upstream of exon 6 in the SEDL gene in two families, and a heterozygous mutation was found in a female carrier. In addition, no mutation was found in the other members of the family. CONCLUSION SEDT in this family was caused by a G/C missense mutation in exon 6 of the SEDL gene, previously not shown to be associated with X-linked SEDT.
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Affiliation(s)
- Lei Kong
- Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University, China
- Shandong Clinical Medical Centre of Endocrinology and Metabolism, China
- Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, China
| | | | - Shanshan Li
- Metabolic Bone Disease and Genetics Research Unit, Department of Osteoporosis and Bone Diseases, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, China
- Shanghai Key Clinical Centre for Metabolic Disease, China
| | | | - Xiuyun Jiang
- Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University, China
- Shandong Clinical Medical Centre of Endocrinology and Metabolism, China
- Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, China
| | - Qingbo Guan
- Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University, China
- Shandong Clinical Medical Centre of Endocrinology and Metabolism, China
- Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, China
| | - Zhenlin Zhang
- Metabolic Bone Disease and Genetics Research Unit, Department of Osteoporosis and Bone Diseases, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, China
- Shanghai Key Clinical Centre for Metabolic Disease, China
| | - Fei Jing
- Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University, China
- Shandong Clinical Medical Centre of Endocrinology and Metabolism, China
- Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, China
| | - Jin Xu
- Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University, China
- Shandong Clinical Medical Centre of Endocrinology and Metabolism, China
- Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, China
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4
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Brunet S, Shahrzad N, Saint-Dic D, Dutczak H, Sacher M. Atrs20Mutation That Mimics an SEDT-Causing Mutation Blocks Selective and Non-Selective Autophagy: A Model for TRAPP III Organization. Traffic 2013; 14:1091-104. [DOI: 10.1111/tra.12095] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Revised: 07/28/2013] [Accepted: 07/30/2013] [Indexed: 02/04/2023]
Affiliation(s)
- Stephanie Brunet
- Department of Biology; Concordia University; Montreal; Quebec; Canada
| | - Nassim Shahrzad
- Department of Biology; Concordia University; Montreal; Quebec; Canada
| | - Djenann Saint-Dic
- Department of Biology; Concordia University; Montreal; Quebec; Canada
| | - Hartley Dutczak
- Department of Biology; Concordia University; Montreal; Quebec; Canada
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Wang H, Wu W, Xu Z, Xie J. A novel splicing mutation in the SEDL gene causes spondyloepiphyseal dysplasia tarda in a large Chinese pedigree. Clin Chim Acta 2013; 425:30-3. [PMID: 23876379 DOI: 10.1016/j.cca.2013.07.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2013] [Revised: 07/01/2013] [Accepted: 07/02/2013] [Indexed: 11/26/2022]
Abstract
The X-linked form of spondyloepiphyseal dysplasia tarda (SEDT, OMIM# 313400) is a rare osteochondrodysplasia caused by mutations in the SEDL (TRAPPC2, OMIM# 300202) gene. It is clinically characterized by disproportionate short stature, barrel-shaped chests and early development of degenerative joint disease. We report here a novel mutation in the intron 3 splice-donor site (c. 93+5G>C) segregated in an X-link pattern in a large Chinese family with SEDT. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis revealed that the mutation causes an aberrant splicing of exon 3, resulting in the elimination of 31 codons in the exon and a considerable loss function of the SEDL protein. This mutation was not detected in the 100 healthy controls. This novel mutation adds to the spectrum of previously-identified disease-causing mutations. Pre-symptomatic molecular diagnosis and prenatal diagnosis of the pregnant carriers could be helpful to families with SEDT.
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Affiliation(s)
- Hui Wang
- Prenatal Diagnosis Center, Shenzhen Maternity and Child Healthcare Hospital, Shenzhen, Guangdong Province, China
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Xie X, Liao L, Gao J, Luo X. A novel COMP mutation in a Chinese patient with pseudoachondroplasia. Gene 2013; 522:102-6. [PMID: 23562786 DOI: 10.1016/j.gene.2013.02.056] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2012] [Revised: 02/16/2013] [Accepted: 02/19/2013] [Indexed: 10/27/2022]
Abstract
A 2.75-year-old Chinese boy presented with typical clinical features of pseudoachondroplasia, including disproportionate short-limb short stature, brachydactyly, genu varus and waddling gait. Radiologically, tubular bones were short with widened metaphyses, irregular and small epiphyses; anterior tonguing or beaking of vertebral bodies were characteristic. DNA sequencing analysis of the COMP gene revealed a heterozygous mutation (c.1511G>A, p.Cys504Tyr) in the patient but his parents were unaffected without this genetic change. The missense mutation (c.1511G>A) was not found in 100 healthy controls and has not been reported previously. Our findings expand the spectrum of known mutations in COMP leading to pseudoachondroplasia.
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Affiliation(s)
- Xuemei Xie
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
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Taussig D, Lipatova Z, Kim JJ, Zhang X, Segev N. Trs20 is required for TRAPP II assembly. Traffic 2013; 14:678-90. [PMID: 23465091 DOI: 10.1111/tra.12065] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Revised: 02/22/2013] [Accepted: 03/07/2013] [Indexed: 11/28/2022]
Abstract
The modular TRAPP complexes act as nucleotide exchangers to activate the Golgi Ypt/Rab GTPases, Ypt1 and Ypt31/Ypt32. In yeast, TRAPP I acts at the cis-Golgi and its assembly and structure are well characterized. In contrast, TRAPP II acts at the trans-Golgi and is poorly understood. Especially puzzling is the role of Trs20, an essential TRAPP I/II subunit required neither for the assembly of TRAPP I nor for its Ypt1-exchange activity. Mutations in Sedlin, the human functional ortholog of Trs20, cause the cartilage-specific disorder SEDT. Here we show that Trs20 interacts with the TRAPP II-specific subunit Trs120. Furthermore, the Trs20-Trs120 interaction is required for assembly of TRAPP II and for its Ypt32-exchange activity. Finally, Trs20-D46Y, with a single-residue substitution equivalent to a SEDT-causing mutation in Sedlin, interacts with TRAPP I, but the resulting TRAPP complex cannot interact with Trs120 and TRAPP II cannot be assembled. These results indicate that Trs20 is crucial for assembly of TRAPP II, and the defective assembly caused by a SEDT-linked mutation suggests that this role is conserved.
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Affiliation(s)
- David Taussig
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, USA
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Mahfouz H, Ragnini-Wilson A, Venditti R, De Matteis MA, Wilson C. Mutational analysis of the yeast TRAPP subunit Trs20p identifies roles in endocytic recycling and sporulation. PLoS One 2012; 7:e41408. [PMID: 23049729 PMCID: PMC3458868 DOI: 10.1371/journal.pone.0041408] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Accepted: 06/22/2012] [Indexed: 11/20/2022] Open
Abstract
Trs20p is a subunit of the evolutionarily conserved TRAPP (TRAnsport Protein Particle) complex that mediates various aspects of membrane trafficking. Three TRAPP complexes have been identified in yeast with roles in ER-to-Golgi trafficking, post-Golgi and endosomal-to-Golgi transport and in autophagy. The role of Trs20p, which is essential for viability and a component of all three complexes, and how it might function within each TRAPP complex, has not been clarified to date. To begin to address the role of Trs20p we generated different mutants by random mutagenesis but, surprisingly, no defects were observed in diverse anterograde transport pathways or general secretion in Trs20 temperature-sensitive mutants. Instead, mutation of Trs20 led to defects in endocytic recycling and a block in sporulation/meiosis. The phenotypes of different mutants appear to be separable suggesting that the mutations affect the function of Trs20 in different TRAPP complexes.
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Affiliation(s)
- Hichem Mahfouz
- Consorzio Mario Negri Sud, Santa Maria Imbaro, Chieti, Italy
| | - Antonella Ragnini-Wilson
- Department of Biology, University of Rome “Tor Vergata”, Rome, Italy
- Consorzio Mario Negri Sud, Santa Maria Imbaro, Chieti, Italy
| | | | | | - Cathal Wilson
- Telethon Institute of Genetics and Medicine, Naples, Italy
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9
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Duarte DT, Hul S, Sacher M. A yeast two hybrid screen identifies SPATA4 as a TRAPP interactor. FEBS Lett 2011; 585:2676-81. [PMID: 21827752 DOI: 10.1016/j.febslet.2011.07.040] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Revised: 07/25/2011] [Accepted: 07/26/2011] [Indexed: 11/17/2022]
Abstract
The TRAPP vesicle-tethering complex consists of more than 10 distinct polypeptides and is involved in protein transport. Using the C2 subunit as bait we identified SPATA4, a spermatocyte-specific protein of unknown function, as an interacting partner in a yeast two hybrid screen. Further studies indicate SPATA4 interacts with the C2 portion of the TRAPP complex. SPATA4 fractionates with both cytosolic and nuclear fractions suggesting it may have several distinct functions. SPATA4 is one of only three human proteins that contain a DUF1042 domain and we show that C2 does not interact with another one of the DUF1042 domain-containing proteins. Our results suggest a role for SPATA4 in membrane traffic and a specialized function for TRAPP in spermatocytes.
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10
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Jeyabalan J, Nesbit MA, Galvanovskis J, Callaghan R, Rorsman P, Thakker RV. SEDLIN forms homodimers: characterisation of SEDLIN mutations and their interactions with transcription factors MBP1, PITX1 and SF1. PLoS One 2010; 5:e10646. [PMID: 20498720 PMCID: PMC2871040 DOI: 10.1371/journal.pone.0010646] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2010] [Accepted: 04/22/2010] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND SEDLIN, a 140 amino acid subunit of the Transport Protein Particle (TRAPP) complex, is ubiquitously expressed and interacts with the transcription factors c-myc promoter-binding protein 1 (MBP1), pituitary homeobox 1 (PITX1) and steroidogenic factor 1 (SF1). SEDLIN mutations cause X-linked spondyloepiphyseal dysplasia tarda (SEDT). METHODOLOGY/PRINCIPAL FINDINGS We investigated the effects of 4 missense (Asp47Tyr, Ser73Leu, Phe83Ser and Val130Asp) and the most C-terminal nonsense (Gln131Stop) SEDT-associated mutations on interactions with MBP1, PITX1 and SF1 by expression in COS7 cells. Wild-type SEDLIN was present in the cytoplasm and nucleus and interacted with MBP1, PITX1 and SF1; the SEDLIN mutations did not alter these subcellular localizations or the interactions. However, SEDLIN was found to homodimerize, and the formation of dimers between wild-type and mutant SEDLIN would mask a loss in these interactions. A mammalian SEDLIN null cell-line is not available, and the interactions between SEDLIN and the transcription factors were therefore investigated in yeast, which does not endogenously express SEDLIN. This revealed that all the SEDT mutations, except Asp47Tyr, lead to a loss of interaction with MBP1, PITX1 and SF1. Three-dimensional modelling studies of SEDLIN revealed that Asp47 resides on the surface whereas all the other mutant residues lie within the hydrophobic core of the protein, and hence are likely to affect the correct folding of SEDLIN and thereby disrupt protein-protein interactions. CONCLUSIONS/SIGNIFICANCE Our studies demonstrate that SEDLIN is present in the nucleus, forms homodimers and that SEDT-associated mutations cause a loss of interaction with the transcription factors MBP1, PITX1 and SF1.
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Affiliation(s)
- Jeshmi Jeyabalan
- Academic Endocrine Unit, Nuffield Department of Clinical Medicine, Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, United Kingdom
| | - M. Andrew Nesbit
- Academic Endocrine Unit, Nuffield Department of Clinical Medicine, Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, United Kingdom
| | - Juris Galvanovskis
- Diabetes Research Laboratories, Nuffield Department of Clinical Medicine, Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, United Kingdom
| | - Richard Callaghan
- Nuffield Department of Clinical Laboratory Sciences, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom
| | - Patrik Rorsman
- Diabetes Research Laboratories, Nuffield Department of Clinical Medicine, Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, United Kingdom
| | - Rajesh V. Thakker
- Academic Endocrine Unit, Nuffield Department of Clinical Medicine, Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, United Kingdom
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Vedovato M, Rossi V, Dacks JB, Filippini F. Comparative analysis of plant genomes allows the definition of the "Phytolongins": a novel non-SNARE longin domain protein family. BMC Genomics 2009; 10:510. [PMID: 19889231 PMCID: PMC2779197 DOI: 10.1186/1471-2164-10-510] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2009] [Accepted: 11/04/2009] [Indexed: 12/27/2022] Open
Abstract
Background Subcellular trafficking is a hallmark of eukaryotic cells. Because of their pivotal role in the process, a great deal of attention has been paid to the SNARE proteins. Most R-SNAREs, or "longins", however, also possess a highly conserved, N-terminal fold. This "longin domain" is known to play multiple roles in regulating SNARE activity and targeting via interaction with other trafficking proteins. However, the diversity and complement of longins in eukaryotes is poorly understood. Results Our comparative genome survey identified a novel family of longin-related proteins, dubbed the "Phytolongins" because they are specific to land plants. Phytolongins share with longins the N-terminal longin domain and the C-terminal transmembrane domain; however, in the central region, the SNARE motif is replaced by a novel region. Phylogenetic analysis pinpoints the Phytolongins as a derivative of the plant specific VAMP72 longin sub-family and allows elucidation of Phytolongin evolution. Conclusion "Longins" have been defined as R-SNAREs composed of both a longin domain and a SNARE motif. However, expressed gene isoforms and splice variants of longins are examples of non-SNARE motif containing longins. The discovery of Phytolongins, a family of non-SNARE longin domain proteins, together with recent evidence on the conservation of the longin-like fold in proteins involved in both vesicle fusion (e.g. the Trs20 tether) and vesicle formation (e.g. σ and μ adaptin) highlight the importance of the longin-like domain in protein trafficking and suggest that it was one of the primordial building blocks of the eukaryotic membrane-trafficking machinery.
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Affiliation(s)
- Marco Vedovato
- Department of Cell Biology, University of Alberta, Edmonton, Canada.
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12
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Sztul E, Lupashin V. Role of vesicle tethering factors in the ER-Golgi membrane traffic. FEBS Lett 2009; 583:3770-83. [PMID: 19887069 DOI: 10.1016/j.febslet.2009.10.083] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2009] [Revised: 10/29/2009] [Accepted: 10/30/2009] [Indexed: 12/27/2022]
Abstract
Tethers are a diverse group of loosely related proteins and protein complexes grouped into three families based on structural and functional similarities. A well-accepted role for tethering factors is the initial attachment of transport carriers to acceptor membranes prior to fusion. However, accumulating evidence indicates that tethers are more than static bridges. Tethers have been shown to interact with components of the fusion machinery and with components involved in vesicle formation. Tethers belonging to the three families act at the same stage of traffic, suggesting that they mediate distinct events during vesicle tethering. Thus, multiple tether-facilitated events are required to provide selectivity to vesicle fusion. In this review, we highlight findings that support this model.
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Affiliation(s)
- Elizabeth Sztul
- Department of Cell Biology, University of Alabama at Birmingham, 1918 University Boulevard, Birmingham, AL 35294, USA
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13
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Biochemical consequences of sedlin mutations that cause spondyloepiphyseal dysplasia tarda. Biochem J 2009; 423:233-42. [DOI: 10.1042/bj20090541] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
SEDT (spondyloepiphyseal dysplasia tarda) is a late-onset X-linked recessive skeletal dysplasia caused by mutations in the gene SEDL coding for sedlin. In the present paper, we investigated four missense mutations observed in SEDT and compare biochemical and cellular characteristics relative to the wild-type protein to address the mechanism of disease and to gain insight into the function of the sedlin protein. In situ hybridization and immunohistochemical experiments in mouse growth plates revealed sedlin to be predominantly expressed in proliferating and hypertrophic chondrocytes. Cell culture studies showed that the wild-type protein localized predominantly in the vicinity of the nucleus and the Golgi, with further localization around the cytoplasm, whereas mutation resulted in mislocalization. The D47Y mutant was expressed similarly to the wild-type, but the S73L, F83S and V130D mutants showed particularly low levels of expression that were rescued in the presence of the proteasome inhibitor MG132 (benzyloxycarbonyl-leucylleucylleucinal). Furthermore, whereas the D47Y mutant folded similarly and had similar stability to the wild-type sedlin as shown by CD and fluorescence, the S73L, F83S and V130D mutants all misfolded during expression. Two independent assays showed that the D47Y mutation resulted in an increased affinity for the transport protein particle component Bet3 compared with the wild-type sedlin. Our results suggest that the sedlin mutations S73L, F83S and V130D cause SEDT by sedlin misfolding, whereas the D47Y mutation may influence normal TRAPP (transport protein particle) dynamics.
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Ren M, Feng H, Fu Y, Land M, Rubin CS. Protein kinase D is an essential regulator of C. elegans innate immunity. Immunity 2009; 30:521-32. [PMID: 19371715 DOI: 10.1016/j.immuni.2009.03.007] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2007] [Revised: 08/08/2008] [Accepted: 03/05/2009] [Indexed: 10/20/2022]
Abstract
Protein kinase D (PKD) mediates signal transduction downstream from phospholipase C and diacylglycerol (DAG). PKDs are activated by hormones and stress in cell lines, but little is known about PKD functions and regulation in vivo. Here, we show that DKF-2, a C. elegans PKD, regulates innate immunity. Animals lacking DKF-2 were hypersensitive to killing by bacteria that are pathogens of C. elegans and humans. DKF-2 induced 85 mRNAs, which encode antimicrobial peptides and proteins that sustain intestinal epithelium. Induction of immune effector mRNAs by DKF-2 proceeded via PMK-1 (p38 Map-kinase)-dependent and -independent pathways. TPA-1, a PKCdelta homolog, regulated activation and functions of DKF-2 in vivo. Therefore, DKF-2 provides a molecular link that couples DAG signaling to regulation of immunity. This intersection between DAG-TPA-1-DKF-2 and PMK-1 pathways enables integrated immune responses to multiple stimuli. Thus, a PKD mobilizes activation of host immune defenses against pathogens by previously unappreciated signaling pathways and mechanisms.
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Affiliation(s)
- Min Ren
- Department of Molecular Pharmacology, Atran Laboratories, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
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15
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A novel RNA-splicing mutation in TRAPPC2 gene causing X-linked spondyloepiphyseal dysplasia tarda in a large Chinese family. J Genet 2009; 88:87-91. [DOI: 10.1007/s12041-009-0012-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Scrivens PJ, Shahrzad N, Moores A, Morin A, Brunet S, Sacher M. TRAPPC2L is a novel, highly conserved TRAPP-interacting protein. Traffic 2009; 10:724-36. [PMID: 19416478 DOI: 10.1111/j.1600-0854.2009.00906.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Mutations in the trafficking protein particle complex C2 protein (TRAPPC2), a mammalian ortholog of yeast Trs20p and a component of the trafficking protein particle (TRAPP) vesicle tethering complex, have been linked to the skeletal disorder spondyloepiphyseal dysplasia tarda (SEDT). Intriguingly, the X-linked TRAPPC2 is just one of a complement of Trs20-related genes in humans. Here we characterize TRAPPC2L, a novel, highly conserved TRAPP-interacting protein related to TRAPPC2 and the uncharacterized yeast open reading frame YEL048c. TRAPPC2L and TRAPPC2 genes are found in pairs across species and show broad and overlapping expression, suggesting they are functionally distinct, a notion supported by yeast complementation studies and biochemical characterization. RNA interference-mediated knockdown of either TRAPPC2L or TRAPPC2 in HeLa cells leads to fragmentation of the Golgi, implicating both proteins in Golgi dynamics. Gradient fractionation of cellular membranes indicates that TRAPPC2L is found with a portion of cellular TRAPP on very low-density membranes whereas the remainder of TRAPP, but not TRAPPC2L, is found associated with Golgi markers. YEL048c displays genetic interactions with TRAPP II-encoding genes and the gene product co-fractionates with and interacts with yeast TRAPP II. Taken together these results indicate that TRAPPC2L and its yeast ortholog YEL048c are novel TRAPP-interacting proteins that may modulate the function of the TRAPP II complex.
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Affiliation(s)
- P James Scrivens
- Concordia University, Department of Biology, Montreal, Quebec, Canada
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Dimitrov A, Paupe V, Gueudry C, Sibarita JB, Raposo G, Vielemeyer O, Gilbert T, Csaba Z, Attie-Bitach T, Cormier-Daire V, Gressens P, Rustin P, Perez F, El Ghouzzi V. The gene responsible for Dyggve-Melchior-Clausen syndrome encodes a novel peripheral membrane protein dynamically associated with the Golgi apparatus. Hum Mol Genet 2008; 18:440-53. [PMID: 18996921 DOI: 10.1093/hmg/ddn371] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Dyggve-Melchior-Clausen dysplasia (DMC) is a rare inherited dwarfism with severe mental retardation due to mutations in the DYM gene which encodes Dymeclin, a 669-amino acid protein of yet unknown function. Despite a high conservation across species and several predicted transmembrane domains, Dymeclin could not be ascribed to any family of proteins. Here we show, using in situ hybridization, that DYM is widely expressed in human embryos, especially in the cortex, the hippocampus and the cerebellum. Both the endogenous and the recombinant protein fused to green fluorescent protein co-localized with Golgi apparatus markers. Electron microscopy revealed that Dymeclin associates with the Golgi apparatus and with transitional vesicles of the reticulum-Golgi interface. Moreover, permeabilization assays revealed that Dymeclin is not a transmembrane but a peripheral protein of the Golgi apparatus as it can be completely released from the Golgi after permeabilization of the plasma membrane. Time lapse confocal microscopy experiments on living cells further showed that the protein shuttles between the cytosol and the Golgi apparatus in a highly dynamic manner and recognizes specifically a subset of mature Golgi membranes. Finally, we found that DYM mutations associated with DMC result in mis-localization and subsequent degradation of Dymeclin. These data indicate that DMC results from a loss-of-function of Dymeclin, a novel peripheral membrane protein which shuttles rapidly between the cytosol and mature Golgi membranes and point out a role of Dymeclin in cellular trafficking.
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18
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Abstract
Vesicle‐mediated transport is a process carried out by virtually every cell and is required for the proper targeting and secretion of proteins. As such, there are numerous players involved to ensure that the proteins are properly localized. Overall, transport requires vesicle budding, recognition of the vesicle by the target membrane and fusion of the vesicle with the target membrane resulting in delivery of its contents. The initial interaction between the vesicle and the target membrane has been referred to as tethering. Because this is the first contact between the two membranes, tethering is critical to ensuring that specificity is achieved. It is therefore not surprising that there are numerous ‘tethering factors’ involved ranging from multisubunit complexes, coiled‐coil proteins and Rab guanosine triphosphatases. Of the multisubunit tethering complexes, one of the best studied at the molecular level is the evolutionarily conserved TRAPP complex. There are two forms of this complex: TRAPP I and TRAPP II. In yeast, these complexes function in a number of processes including endoplasmic reticulum‐to‐Golgi transport (TRAPP I) and an ill‐defined step at the trans Golgi (TRAPP II). Because the complex was first reported in 1998 (1), there has been a decade of studies that have clarified some aspects of its function but have also raised further questions. In this review, we will discuss recent advances in our understanding of yeast and mammalian TRAPP at the structural and functional levels and its role in disease while trying to resolve some apparent discrepancies and highlighting areas for future study.
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Affiliation(s)
- Michael Sacher
- Department of Biology, Concordia University, Montreal, QC, Canada.
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Dyggve-Melchior-Clausen syndrome: chondrodysplasia resulting from defects in intracellular vesicle traffic. Proc Natl Acad Sci U S A 2008; 105:16171-6. [PMID: 18852472 DOI: 10.1073/pnas.0804259105] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Dyggve-Melchior-Clausen syndrome and Smith-McCort dysplasia are recessive spondyloepimetaphyseal dysplasias caused by loss-of-function mutations in dymeclin (Dym), a gene with previously unknown function. Here we report that Dym-deficient mice display defects in endochondral bone formation similar to that of Dyggve-Melchior-Clausen syndrome and Smith-McCort dysplasia, demonstrating functional conservation between the two species. Dym-mutant cells display multiple defects in vesicle traffic, as evidenced by enhanced dispersal of Golgi markers in interphase cells, delayed Golgi reassembly after brefeldin A treatment, delayed retrograde traffic of an endoplasmic reticulum-targeted Shiga toxin B subunit, and altered furin trafficking; and the Dym protein associates with multiple cellular proteins involved in vesicular traffic. These results establish dymeclin as a novel protein involved in Golgi organization and intracellular vesicle traffic and clarify the molecular basis for chondrodysplasia in mice and men.
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Heinicke S, Livstone MS, Lu C, Oughtred R, Kang F, Angiuoli SV, White O, Botstein D, Dolinski K. The Princeton Protein Orthology Database (P-POD): a comparative genomics analysis tool for biologists. PLoS One 2007; 2:e766. [PMID: 17712414 PMCID: PMC1942082 DOI: 10.1371/journal.pone.0000766] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2007] [Accepted: 07/18/2007] [Indexed: 02/07/2023] Open
Abstract
Many biological databases that provide comparative genomics information and tools are now available on the internet. While certainly quite useful, to our knowledge none of the existing databases combine results from multiple comparative genomics methods with manually curated information from the literature. Here we describe the Princeton Protein Orthology Database (P-POD, http://ortholog.princeton.edu), a user-friendly database system that allows users to find and visualize the phylogenetic relationships among predicted orthologs (based on the OrthoMCL method) to a query gene from any of eight eukaryotic organisms, and to see the orthologs in a wider evolutionary context (based on the Jaccard clustering method). In addition to the phylogenetic information, the database contains experimental results manually collected from the literature that can be compared to the computational analyses, as well as links to relevant human disease and gene information via the OMIM, model organism, and sequence databases. Our aim is for the P-POD resource to be extremely useful to typical experimental biologists wanting to learn more about the evolutionary context of their favorite genes. P-POD is based on the commonly used Generic Model Organism Database (GMOD) schema and can be downloaded in its entirety for installation on one's own system. Thus, bioinformaticians and software developers may also find P-POD useful because they can use the P-POD database infrastructure when developing their own comparative genomics resources and database tools.
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Affiliation(s)
- Sven Heinicke
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America
| | - Michael S. Livstone
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America
| | - Charles Lu
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America
| | - Rose Oughtred
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America
| | - Fan Kang
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America
| | - Samuel V. Angiuoli
- The Institute for Genomic Research, Rockville, Maryland, United States of America
- Center for Bioinformatics and Computational Biology, University of Maryland, College Park, Maryland, United States of America
| | - Owen White
- The Institute for Genomic Research, Rockville, Maryland, United States of America
| | - David Botstein
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America
| | - Kara Dolinski
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America
- * To whom correspondence should be addressed. E-mail:
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21
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Baines AC, Zhang B. Receptor-mediated protein transport in the early secretory pathway. Trends Biochem Sci 2007; 32:381-8. [PMID: 17618120 DOI: 10.1016/j.tibs.2007.06.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2007] [Revised: 05/31/2007] [Accepted: 06/22/2007] [Indexed: 11/25/2022]
Abstract
Many secretory proteins are thought to rely upon transmembrane cargo receptors for efficient endoplasmic reticulum (ER)-to-Golgi transport. These receptors recognize specific cargo-encoded sorting signals. Only a few such cargo receptors have been characterized in detail, most of them in yeast. The only well-defined cargo receptor from mammalian cells, the LMAN1-MCFD2 complex, is required for the efficient secretion of coagulation factors V and VIII. Studies of this complex, coupled with recent advances in elucidating the basic machinery that mediates ER-to-Golgi transport, have provided a more-detailed picture of the mechanisms underlying receptor-mediated transport in the early secretory pathway. In addition to yeast studies, insights have also come from investigations into several inherited disorders that have recently been attributed to defects in the secretory pathway.
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Affiliation(s)
- Andrea C Baines
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109-2216, USA
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Lupashin V, Sztul E. Golgi tethering factors. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2005; 1744:325-39. [PMID: 15979505 DOI: 10.1016/j.bbamcr.2005.03.013] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2005] [Revised: 03/30/2005] [Accepted: 03/31/2005] [Indexed: 10/25/2022]
Abstract
Transport of cargo to, through and from the Golgi complex is mediated by vesicular carriers and transient tubular connections. In this review, we describe vesicle tethering events with the understanding that similar events occur during transport via larger structures. Tethering factors can be generally divided into a group of coiled-coil proteins and a group of multi-subunit complexes. Current evidence suggests that these factors function in a variety of membrane-membrane tethering events at the Golgi complex, interact with SNARE molecules, and are regulated by small GTPases of the Rab and Arl families.
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Affiliation(s)
- Vladimir Lupashin
- Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Biomed 261-2, Slot 505, 200 South Cedar St, Little Rock, AR 72205, USA.
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Turnbull AP, Kümmel D, Prinz B, Holz C, Schultchen J, Lang C, Niesen FH, Hofmann KP, Delbrück H, Behlke J, Müller EC, Jarosch E, Sommer T, Heinemann U. Structure of palmitoylated BET3: insights into TRAPP complex assembly and membrane localization. EMBO J 2005; 24:875-84. [PMID: 15692564 PMCID: PMC554119 DOI: 10.1038/sj.emboj.7600565] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2004] [Accepted: 01/04/2005] [Indexed: 11/09/2022] Open
Abstract
BET3 is a component of TRAPP, a complex involved in the tethering of transport vesicles to the cis-Golgi membrane. The crystal structure of human BET3 has been determined to 1.55-A resolution. BET3 adopts an alpha/beta-plait fold and forms dimers in the crystal and in solution, which predetermines the architecture of TRAPP where subunits are present in equimolar stoichiometry. A hydrophobic pocket within BET3 buries a palmitate bound through a thioester linkage to cysteine 68. BET3 and yeast Bet3p are palmitoylated in recombinant yeast cells, the mutant proteins BET3 C68S and Bet3p C80S remain unmodified. Both BET3 and BET3 C68S are found in membrane and cytosolic fractions of these cells; in membrane extractions, they behave like tightly membrane-associated proteins. In a deletion strain, both Bet3p and Bet3p C80S rescue cell viability. Thus, palmitoylation is neither required for viability nor sufficient for membrane association of BET3, which may depend on protein-protein contacts within TRAPP or additional, yet unidentified modifications of BET3. A conformational change may facilitate palmitoyl extrusion from BET3 and allow the fatty acid chain to engage in intermolecular hydrophobic interactions.
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Affiliation(s)
- Andrew P Turnbull
- Max-Delbrück-Centrum für Molekulare Medizin, Berlin, Germany
- Protein Structure Factory, c/o BESSY GmbH, Berlin, Germany
| | - Daniel Kümmel
- Max-Delbrück-Centrum für Molekulare Medizin, Berlin, Germany
| | - Bianka Prinz
- Institut für Biotechnologie, FG Mikrobiologie und Genetik, Technische Universität Berlin, Berlin, Germany
- Protein Structure Factory, Heubnerweg, Berlin, Germany
| | - Caterina Holz
- Institut für Biotechnologie, FG Mikrobiologie und Genetik, Technische Universität Berlin, Berlin, Germany
- Protein Structure Factory, Heubnerweg, Berlin, Germany
| | - Jeffrey Schultchen
- Institut für Biotechnologie, FG Mikrobiologie und Genetik, Technische Universität Berlin, Berlin, Germany
- Protein Structure Factory, Heubnerweg, Berlin, Germany
| | - Christine Lang
- Institut für Biotechnologie, FG Mikrobiologie und Genetik, Technische Universität Berlin, Berlin, Germany
- Protein Structure Factory, Heubnerweg, Berlin, Germany
| | - Frank H Niesen
- Protein Structure Factory, Heubnerweg, Berlin, Germany
- Institut für Medizinische Physik und Biophysik, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Klaus-Peter Hofmann
- Institut für Medizinische Physik und Biophysik, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Heinrich Delbrück
- Protein Structure Factory, Heubnerweg, Berlin, Germany
- Institut für Chemie/Kristallographie, Freie Universität Berlin, Berlin, Germany
| | - Joachim Behlke
- Max-Delbrück-Centrum für Molekulare Medizin, Berlin, Germany
| | | | - Ernst Jarosch
- Max-Delbrück-Centrum für Molekulare Medizin, Berlin, Germany
| | - Thomas Sommer
- Max-Delbrück-Centrum für Molekulare Medizin, Berlin, Germany
| | - Udo Heinemann
- Max-Delbrück-Centrum für Molekulare Medizin, Berlin, Germany
- Institut für Chemie/Kristallographie, Freie Universität Berlin, Berlin, Germany
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Shaw MA, McDonough B, Hodess AB, Harter DH, Gécz J. Identification of aSEDLgene mutation in an individual with Leber hereditary optic neuropathy and spondyloepiphyseal dysplasia. Am J Med Genet A 2004; 129A:206-7. [PMID: 15316971 DOI: 10.1002/ajmg.a.30161] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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