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Jakoby M, Stephan L, Heinemann B, Hülskamp M. Mutations in RABE1C suppress the spirrig mutant phenotype. PLoS One 2024; 19:e0304001. [PMID: 38885274 PMCID: PMC11182498 DOI: 10.1371/journal.pone.0304001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 05/03/2024] [Indexed: 06/20/2024] Open
Abstract
The plant BEACH-domain protein SPIRRIG (SPI) is involved in regulating cell morphogenesis and salt stress responses in Arabidopsis thaliana, Arabis alpina, and Marchantia polymorpha and was reported to function in the context of two unrelated cellular processes: vesicular trafficking and P-body mediated RNA metabolism. To further explore the molecular function of SPI, we isolated a second-site mutant, specifically rescuing the spi mutant trichome phenotype. The molecular analysis of the corresponding gene revealed a dominant negative mutation in RABE1C, a ras-related small GTP-binding protein that localizes to Golgi. Taken together, our data identified the genetic interaction between RABE1C and SPI, which is beneficial for further dissecting the function of SPI in vesicle trafficking-associated cell morphogenesis.
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Affiliation(s)
- Marc Jakoby
- Botanical Institute, Biocenter, Cologne University, Cologne, Germany
| | - Lisa Stephan
- Botanical Institute, Biocenter, Cologne University, Cologne, Germany
| | - Björn Heinemann
- Institute for Plant Sciences, Cluster of Excellence on Plant Sciences (CEPLAS), Cologne University, Cologne, Germany
| | - Martin Hülskamp
- Botanical Institute, Biocenter, Cologne University, Cologne, Germany
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2
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Rai P, Kumar Roy J. Endosomal recycling protein Rab11 in Parkin and Pink1 signaling in Drosophila model of Parkinson's disease. Exp Cell Res 2022; 420:113357. [PMID: 36116557 DOI: 10.1016/j.yexcr.2022.113357] [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: 06/30/2022] [Revised: 08/23/2022] [Accepted: 09/11/2022] [Indexed: 11/16/2022]
Abstract
Neurodegenerative diseases are progressive disorders of the nervous system primarily affecting the loss of neuronal cells present in the brain. Although most neurodegenerative cases are sporadic, some familial genes are found to be involved in the neurodegenerative diseases. The extensively studied parkin and pink1 gene products are known to be involved in the removal of damaged mitochondria via autophagy (mitophagy), a quality control process. If the function of any of these genes is somehow disrupted, accumulation of damaged mitochondria occurs in the forms of protein aggregates in the cytoplasm, leading to formation of the Lewy-bodies. Autophagy is an important catabolic process where the endosomal Rab proteins are seen to be involved. Rab11, an endosomal recycling protein, serves as an ATG9A carrier that helps in autophagosome formation and maturation. Earlier studies have reported that loss of Rab11 prevents the fusion of autophagosomes with the late endosomes hampering the autophagy pathway resulting in apoptosis of cells. In this study, we have emphasized on the importance and functional role of Rab11 in the molecular pathway of Parkin/Pink1 in Parkinson's disease.
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Affiliation(s)
- Pooja Rai
- Cytogenetics Laboratory, Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi, 221005, India.
| | - Jagat Kumar Roy
- Cytogenetics Laboratory, Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi, 221005, India.
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3
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Abbas M, Fan YH, Shi XK, Gao L, Wang YL, Li T, Cooper AMW, Silver K, Zhu KY, Zhang JZ. Identification of Rab family genes and functional analyses of LmRab5 and LmRab11A in the development and RNA interference of Locusta migratoria. INSECT SCIENCE 2022; 29:320-332. [PMID: 34347932 DOI: 10.1111/1744-7917.12921] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 02/26/2021] [Accepted: 03/13/2021] [Indexed: 06/13/2023]
Abstract
Rab proteins constitute the largest family of small GTPases, which play pivotal roles in intracellular membrane trafficking in all eukaryotes. A number of Rab genes have been identified in eukaryotes; however, very little information about these genes has been reported in insects. In the current study, for the first time we identified and characterized 27 Rab family genes from Locusta migratoria. Phylogenetic analysis and comparison of domain architecture indicated that Rab family genes are highly conserved among insect species. Tissue-dependent expression profiles indicated that expression of Rab genes was highest in the ovary, except for LmRab3, which was most highly expressed in hemolymph. The biological function of each Rab gene was investigated using RNA interference (RNAi). Double-stranded RNA targeting each Rab gene was injected into the hemocoel of nymphs and revealed that suppression of two Rab genes (LmRab5 and LmRab11A) caused 100% mortality. In addition, nymphs injected with dsLmRab5 exhibited severe phenotypic defects in the gastric caeca and midgut, while dsLmRab11A arrested the molting process. We then applied the RNAi of RNAi technique to test if silencing either of these two genes would affect the suppression of the lethal giant larvae (LmLgl) reporter gene and found that suppression of LmRab5 diminished the RNAi efficiency of LmLgl, whereas suppression of LmRab11A enhanced RNAi efficiency of LmLgl. These results indicate that Rab genes contribute differently to RNAi efficiency in different tissues. Our study provides a foundation for further functional investigations of Rab genes and their contributions to RNAi efficiency in L. migratoria.
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Affiliation(s)
- Mureed Abbas
- Institute of Applied Biology, Shanxi University, Taiyuan, China
| | - Yun-He Fan
- Institute of Applied Biology, Shanxi University, Taiyuan, China
- College of Life Science, Shanxi University, Taiyuan, China
| | - Xue-Kai Shi
- Institute of Applied Biology, Shanxi University, Taiyuan, China
- College of Life Science, Shanxi University, Taiyuan, China
| | - Lu Gao
- Institute of Applied Biology, Shanxi University, Taiyuan, China
- College of Life Science, Shanxi University, Taiyuan, China
| | - Yan-Li Wang
- Institute of Applied Biology, Shanxi University, Taiyuan, China
| | - Tao Li
- Institute of Applied Biology, Shanxi University, Taiyuan, China
| | | | - Kristopher Silver
- Department of Entomology, Kansas State University, Manhattan, Kansas, USA
| | - Kun Yan Zhu
- Department of Entomology, Kansas State University, Manhattan, Kansas, USA
| | - Jian-Zhen Zhang
- Institute of Applied Biology, Shanxi University, Taiyuan, China
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4
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Schneider K, Farr T, Pinter N, Schmitt K, Valerius O, Braus GH, Kämper J. The Nma1 protein promotes long distance transport mediated by early endosomes in Ustilago maydis. Mol Microbiol 2021; 117:334-352. [PMID: 34817894 DOI: 10.1111/mmi.14851] [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: 06/11/2021] [Revised: 11/18/2021] [Accepted: 11/21/2021] [Indexed: 11/28/2022]
Abstract
Early endosomes (EEs) are part of the endocytic transport pathway and resemble the earliest class of transport vesicles between the internalization of extracellular material, their cellular distribution or vacuolar degradation. In filamentous fungi, EEs fulfill important functions in long distance transport of cargoes as mRNAs, ribosomes, and peroxisomes. Formation and maturation of early endosomes is controlled by the specific membrane-bound Rab-GTPase Rab5 and tethering complexes as CORVET (class C core vacuole/endosome tethering). In the basidiomycete Ustilago maydis, Rab5a is the prominent GTPase to recruit CORVET to EEs; in rab5a deletion strains, this function is maintained by the second EE-associated GTPase Rab5b. The tethering- and core-subunits of CORVET are essential, buttressing a central role for EE transport in U. maydis. The function of EEs in long distance transport is supported by the Nma1 protein that interacts with the Vps3 subunit of CORVET. The interaction stabilizes the binding of Vps3 to the CORVET core complex that is recruited to Rab5a via Vps8. Deletion of nma1 leads to a significantly reduced number of EEs, and an increased conversion rate of EEs to late endosomes. Thus, Nma1 modulates the lifespan of EEs to ensure their availability for the various long distance transport processes.
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Affiliation(s)
- Karina Schneider
- Institute of Applied Biosciences, Department of Genetics, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Theresa Farr
- Institute of Applied Biosciences, Department of Genetics, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Niko Pinter
- Institute of Applied Biosciences, Department of Genetics, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Kerstin Schmitt
- Department of Molecular Microbiology and Genetics and Göttingen Center for Molecular Biosciences (GZMB), University of Göttingen, Göttingen, Germany
| | - Oliver Valerius
- Department of Molecular Microbiology and Genetics and Göttingen Center for Molecular Biosciences (GZMB), University of Göttingen, Göttingen, Germany
| | - Gerhard H Braus
- Department of Molecular Microbiology and Genetics and Göttingen Center for Molecular Biosciences (GZMB), University of Göttingen, Göttingen, Germany
| | - Jörg Kämper
- Institute of Applied Biosciences, Department of Genetics, Karlsruhe Institute of Technology, Karlsruhe, Germany
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Genome-wide toxicogenomic study of the lanthanides sheds light on the selective toxicity mechanisms associated with critical materials. Proc Natl Acad Sci U S A 2021; 118:2025952118. [PMID: 33903247 DOI: 10.1073/pnas.2025952118] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Lanthanides are a series of critical elements widely used in multiple industries, such as optoelectronics and healthcare. Although initially considered to be of low toxicity, concerns have emerged during the last few decades over their impact on human health. The toxicological profile of these metals, however, has been incompletely characterized, with most studies to date solely focusing on one or two elements within the group. In the current study, we assessed potential toxicity mechanisms in the lanthanide series using a functional toxicogenomics approach in baker's yeast, which shares many cellular pathways and functions with humans. We screened the homozygous deletion pool of 4,291 Saccharomyces cerevisiae strains with the lanthanides and identified both common and unique functional effects of these metals. Three very different trends were observed within the lanthanide series, where deletions of certain proteins on membranes and organelles had no effect on the cellular response to early lanthanides while inducing yeast sensitivity and resistance to middle and late lanthanides, respectively. Vesicle-mediated transport (primarily endocytosis) was highlighted by both gene ontology and pathway enrichment analyses as one of the main functions disturbed by the majority of the metals. Protein-protein network analysis indicated that yeast response to lanthanides relied on proteins that participate in regulatory paths used for calcium (and other biologically relevant cations), and lanthanide toxicity included disruption of biosynthetic pathways by enzyme inhibition. Last, multiple genes and proteins identified in the network analysis have human orthologs, suggesting that those may also be targeted by lanthanides in humans.
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Tripathy MK, Deswal R, Sopory SK. Plant RABs: Role in Development and in Abiotic and Biotic Stress Responses. Curr Genomics 2021; 22:26-40. [PMID: 34045922 PMCID: PMC8142350 DOI: 10.2174/1389202922666210114102743] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 12/05/2020] [Accepted: 12/26/2020] [Indexed: 12/15/2022] Open
Abstract
Endosomal trafficking plays an integral role in various eukaryotic cellular activities and is vital for higher-order functions in multicellular organisms. RAB GTPases are important proteins that influence various aspects of membrane traffic, which consequently influence many cellular functions and responses. Compared to yeast and mammals, plants have evolved a unique set of plant-specific RABs that play a significant role in their development. RABs form the largest family of small guanosine triphosphate (GTP)-binding proteins, and are divided into eight sub-families named RAB1, RAB2, RAB5, RAB6, RAB7, RAB8, RAB11 and RAB18. Recent studies on different species suggest that RAB proteins play crucial roles in intracellular trafficking and cytokinesis, in autophagy, plant microbe interactions and in biotic and abiotic stress responses. This review recaptures and summarizes the roles of RABs in plant cell functions and in enhancing plant survival under stress conditions.
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Affiliation(s)
- Manas K Tripathy
- 1International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India; 2Department of Botany, University of Delhi, Delhi 110007, India
| | - Renu Deswal
- 1International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India; 2Department of Botany, University of Delhi, Delhi 110007, India
| | - Sudhir K Sopory
- 1International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India; 2Department of Botany, University of Delhi, Delhi 110007, India
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Agarwal P, Patel K, More P, Sapara KK, Singh VK, Agarwal PK. The AlRabring7 E3-Ub-ligase mediates AlRab7 ubiquitination and improves ionic and oxidative stress tolerance in Saccharomyces cerevisiae. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2020; 151:689-704. [PMID: 32353675 DOI: 10.1016/j.plaphy.2020.03.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 03/13/2020] [Accepted: 03/23/2020] [Indexed: 06/11/2023]
Abstract
The maintenance of ROS homeostasis, membrane biogenesis and recycling of molecules are common stress responses involving specific and complex regulatory network. Ubiquitination is an important and common mechanism which facilitates environmental adaptation in eukaryotes. In the present study we have cloned the AlRabring7, an E3-Ub-ligase, previously identified as AlRab7 interacting partner. The role of AlRabring7 for ubiquitinating AlRab7 and facilitating stress tolerance is analysed. The AlRabring7, with an open-reading frame of 702 bp encodes a protein of 233 amino acids, with RING-HC domain of 40 amino acids. In silico analysis shows that AlRabring7 is a C3HC4-type RING E3 Ub ligase. The protein - protein docking show interaction dynamics between AlRab7-AlRabring7-Ubiquitin proteins. The AlRab7 and AlRabring7 transcript showed up-regulation in response to different salts i.e: NaCl, KCl, CaCl2, NaCl + KCl, NaCl + CaCl2, imposing ionic as well as hyperosmotic stress, and also with oxidative stress by H2O2 treatment. Interestingly, the AlRabring7 showed early transcript expression with maximum expression in shoots on combinatorial stresses. The AlRab7 showed delayed and maximum expression with NaCl + CaCl2 stress treatment. The AlRab7 complements yeast ypt7Δ mutants and restored the fragmented vacuole. The in vitro ubiquitination assay revealed that AlRabring7 function as E3 ubiquitin ligase and mediates AlRab7 ubiquitination. Overexpression of AlRab7 and AlRabring7 independently and when co-transformed enhanced the growth of yeast cells during stress conditions. Further, the bimolecular fluorescence complementation assay shows the in planta interaction of the two proteins. Our results suggest that AlRab7 and AlRabring7 confers enhanced stress tolerance in yeast.
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Affiliation(s)
- Parinita Agarwal
- Plant Omics Division, CSIR-Central Salt and Marine Chemicals Research Institute (CSIR-CSMCRI), Council of Scientific & Industrial Research (CSIR), Gijubhai Badheka Marg, Bhavnagar, 364 002, Gujarat, India.
| | - Khantika Patel
- Plant Omics Division, CSIR-Central Salt and Marine Chemicals Research Institute (CSIR-CSMCRI), Council of Scientific & Industrial Research (CSIR), Gijubhai Badheka Marg, Bhavnagar, 364 002, Gujarat, India
| | - Prashant More
- Plant Omics Division, CSIR-Central Salt and Marine Chemicals Research Institute (CSIR-CSMCRI), Council of Scientific & Industrial Research (CSIR), Gijubhai Badheka Marg, Bhavnagar, 364 002, Gujarat, India; Academy of Scientific and Innovative Research, (AcSIR), Ghaziabad, 201002, India
| | - Komal K Sapara
- Plant Omics Division, CSIR-Central Salt and Marine Chemicals Research Institute (CSIR-CSMCRI), Council of Scientific & Industrial Research (CSIR), Gijubhai Badheka Marg, Bhavnagar, 364 002, Gujarat, India; Academy of Scientific and Innovative Research, (AcSIR), Ghaziabad, 201002, India
| | - Vinay K Singh
- Centre for Bioinformatics, School of Biotechnology, Banaras Hindu University, Varanasi, 221005, Uttar Pradesh, India
| | - Pradeep K Agarwal
- Plant Omics Division, CSIR-Central Salt and Marine Chemicals Research Institute (CSIR-CSMCRI), Council of Scientific & Industrial Research (CSIR), Gijubhai Badheka Marg, Bhavnagar, 364 002, Gujarat, India; Academy of Scientific and Innovative Research, (AcSIR), Ghaziabad, 201002, India
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8
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Bhuin T, Roy JK. Developmental expression, co-localization and genetic interaction of exocyst component Sec15 with Rab11 during Drosophila development. Exp Cell Res 2019; 381:94-104. [PMID: 31071318 DOI: 10.1016/j.yexcr.2019.04.038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 04/17/2019] [Accepted: 04/30/2019] [Indexed: 12/13/2022]
Abstract
Sec15, a component of an evolutionarily conserved octomeric exocyst complex, has been identified as an interactor of GTP-bound Rab11 in mammals and Drosophila which shows its role in secretion in yeast and intracellular vesicle transport. Here, we report the expression patterns of Drosophila Sec15 (DSec15) transcript and Sec15 protein during Drosophila development. At early embryonic stages, a profound level of maternally loaded DSec15 transcript and protein is found. At cellular blastoderm cells (stage 5 embryos); the expression is seen in pole cells, apical membrane and sub-apical region. The transcript is predominantly accumulated in mesoderm, tracheal pits, gut, LE cells, trachea, and ventral nerve cord as development proceeds. While, a robust expression of Sec15 is seen in amnioserosa (AS), lateral epidermis (LAE), developing trachea, gut, ventral nerve cord and epithelial cells. During larval development, the transcript is also found in all imaginal discs with a distinguished accumulation in the morphogenetic furrow of eye disc, gut, proventriculus and gastric ceacae, garland cells/nephrocytes, malpighian tubules, ovary and testis. Further, we show that Sec15 co-localizes with Rab11 during Drosophila embryonic and larval development. Finally, using a genetic approach, we demonstrate that Sec15 interacts with Rab11 in producing blister during Drosophila wing development.
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Affiliation(s)
- Tanmay Bhuin
- Cytogenetics Laboratory, Department of Zoology, Banaras Hindu University, Varanasi, 221 005, India; Department of Zoology, The University of Burdwan, Golapbag, Burdwan, 713104, India.
| | - Jagat K Roy
- Cytogenetics Laboratory, Department of Zoology, Banaras Hindu University, Varanasi, 221 005, India
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9
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Yan H, Huang J, Zhang H, Shim WB. A Rab GTPase protein FvSec4 is necessary for fumonisin B1 biosynthesis and virulence in Fusarium verticillioides. Curr Genet 2019; 66:205-216. [PMID: 31292685 DOI: 10.1007/s00294-019-01013-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Revised: 06/30/2019] [Accepted: 07/01/2019] [Indexed: 10/26/2022]
Abstract
Rab GTPases are responsible for a variety of membrane trafficking and vesicular transportation in fungi. But the role of Rab GTPases in Fusarium verticillioides, one of the key corn pathogens worldwide, remains elusive. These Small GTPases in fungi, particularly those homologous to Saccharomyces cerevisiae Sec4, are known to be associated with protein secretion, vesicular trafficking, secondary metabolism and pathogenicity. In this study, our aim was to investigate the molecular functions of FvSec4 in F. verticillioides associated with physiology and virulence. Interestingly, the FvSec4 null mutation did not impair the expression of key conidiation-related genes. Also, the mutant did not show any defect in sexual development, including perithecia production. Meanwhile, GFP-FvSec4 localized to growing hyphal tips and raised the possibility that FvSec4 is involved in protein trafficking and endocytosis. The mutant exhibited defect in corn stalk rot virulence and also significant alteration of fumonisin B1 production. The mutation led to higher sensitivity to oxidative and cell wall stress agents, and defects in carbon utilization. Gene complementation fully restored the defects in the mutant demonstrating that FvSec4 plays important roles in these functions. Taken together, our data indicate that FvSec4 is critical in F. verticillioides hyphal development, virulence, mycotoxin production and stress responses.
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Affiliation(s)
- Huijuan Yan
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX, 77843, USA
| | - Jun Huang
- Department of Plant Pathology, Kansas State University, Manhattan, KS, 66506, USA
| | - Huan Zhang
- Department of Biology, Texas A&M University, College Station, TX, 77843, USA
| | - Won Bo Shim
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX, 77843, USA.
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10
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Takemura T, Imamura S, Kobayashi Y, Tanaka K. Construction of a Selectable Marker Recycling System and the Use in Epitope Tagging of Multiple Nuclear Genes in the Unicellular Red Alga Cyanidioschyzon merolae. PLANT & CELL PHYSIOLOGY 2018; 59:2308-2316. [PMID: 30099537 DOI: 10.1093/pcp/pcy156] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 07/30/2018] [Indexed: 06/08/2023]
Abstract
The nuclear genome of the unicellular red alga Cyanidioschyzon merolae can be modified by homologous recombination with exogenously introduced DNA. However, it is presently difficult to modify multiple chromosome loci because of the limited number of available positive selectable markers. In this study, we constructed a modified URA5.3 gene (URA5.3T), which can be repeatedly used for nuclear genome transformation, as well as two plasmid vectors for 3× FLAG- or 3× Myc-epitope tagging of nuclear-encoded proteins using URA5.3T. In the URA5.3T marker, the promoter region and open reading frame were located between directly repeated URA5.3 terminator sequences, and the URA5.3 gene can be eliminated by 5-fluoroorotic acid selection through homologous recombination. To demonstrate the utility of the constructed system, a 3× FLAG-tag and 3× Myc-tag were introduced at the C-termini of two of the six Rab proteins in C. merolae, CmRab18 and CmRab7, respectively, and the differential expression levels were successfully monitored by immunoblot analysis using these epitope tags. The URA5.3T marker's introduction and elimination cycle can be repeated. Thus, we have constructed a marker recycling system for C. merolae nuclear transformation. A novel procedure to obtain a high plating efficiency of C. merolae cells on solid gellan gum plates is also presented.
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Affiliation(s)
- Tokiaki Takemura
- Laboratory for Chemistry and Life Science, Institute of Innovative Science, Tokyo Institute of Technology, Nagatsuta, Yokohama, Japan
- School of Life Science and Technology, Tokyo Institute of Technology, Nagatsuta, Yokohama, Japan
| | - Sousuke Imamura
- Laboratory for Chemistry and Life Science, Institute of Innovative Science, Tokyo Institute of Technology, Nagatsuta, Yokohama, Japan
| | - Yuki Kobayashi
- Laboratory for Chemistry and Life Science, Institute of Innovative Science, Tokyo Institute of Technology, Nagatsuta, Yokohama, Japan
| | - Kan Tanaka
- Laboratory for Chemistry and Life Science, Institute of Innovative Science, Tokyo Institute of Technology, Nagatsuta, Yokohama, Japan
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Chua CEL, Tang BL. Rab 10-a traffic controller in multiple cellular pathways and locations. J Cell Physiol 2018; 233:6483-6494. [PMID: 29377137 DOI: 10.1002/jcp.26503] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 01/24/2018] [Indexed: 12/29/2022]
Abstract
Rab GTPases are key regulators of eukaryotic membrane traffic, and their functions and activities are limited to particular intracellular transport steps and their membrane localization is by and large restricted. Some Rabs do participate in more than one transport steps, but broadly speaking, there is a clear demarcation between exocytic and endocytic Rabs. One Rab protein, Rab10, however, appears to be anomalous in this regard and has a diverse array of functions and subcellular localizations. Rab10 has been implicated in a myriad of activities ranging from polarized exocytosis and endosomal sorting in polarized cells, insulin-dependent Glut4 transport in adipocytes, axonal growth in neurons, and endo-phagocytic processes in macrophages. It's reported subcellular localizations include the endoplasmic reticulum (ER), Golgi/TGN, the endosomes/phagosomes and the primary cilia. In this review, we summarize and discuss the multitude of known roles of Rab10 in cellular membrane transport and the molecular players and mechanisms associated with these roles.
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Affiliation(s)
- Christelle En Lin Chua
- Singapore Nuclear Research and Safety Initiative, National University of Singapore, Singapore
| | - Bor L Tang
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore
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12
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Chen C, Eldein S, Zhou X, Sun Y, Gao J, Sun Y, Liu C, Wang L. Immune function of a Rab-related protein by modulating the JAK-STAT signaling pathway in the silkworm, Bombyx mori. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2018; 97:e21434. [PMID: 29193252 DOI: 10.1002/arch.21434] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The Rab-family GTPases mainly regulate intracellular vesicle transport, and play important roles in the innate immune response in invertebrates. However, the function and signal transduction of Rab proteins in immune reactions remain unclear in silkworms. In this study, we analyzed a Rab-related protein of silkworm Bombyx mori (BmRABRP) by raising antibodies against its bacterially expressed recombinant form. Tissue distribution analysis showed that BmRABRP mRNA and protein were high expressed in the Malpighian tubule and fat body, respectively. However, among the different stages, only the fourth instar larvae and pupae showed significant BmRABRP levels. After challenge with four pathogenic microorganisms (Escherichia coli, BmNPV, Beauveria bassiana, Micrococcus luteus), the expression of BmRABRP mRNA in the fat body was significantly upregulated. In contrast, the BmRABRP protein was significantly upregulated after infection with BmNPV, while it was downregulated by E. coli, B. bassiana, and M. luteus. A specific dsRNA was used to explore the immune function and relationship between BmRABRP and the JAK-STAT signaling pathway. After BmRABRP gene interference, significant reduction in the number of nodules and increased mortality suggested that BmRABRP plays an important role in silkworm's response to bacterial challenge. In addition, four key genes (BmHOP, BmSTAT, BmSOCS2, and BmSOCS6) of the JAK-STAT signaling pathway showed significantly altered expressions after BmRABRP silencing. BmHOP and BmSOCS6 expressions were significantly decreased, while BmSTAT and BmSOCS2 were significantly upregulated. Our results suggested that BmRABRP is involved in the innate immune response against pathogenic microorganisms through the JAK-STAT signaling pathway in silkworm.
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Affiliation(s)
- Chen Chen
- College of Life Science, Anhui Agricultural University, Hefei, China
| | - Salah Eldein
- College of Life Science, Anhui Agricultural University, Hefei, China
| | - Xiaosan Zhou
- College of Life Science, Anhui Agricultural University, Hefei, China
| | - Yu Sun
- College of Life Science, Anhui Agricultural University, Hefei, China
| | - Jin Gao
- College of Life Science, Anhui Agricultural University, Hefei, China
| | - Yuxuan Sun
- College of Life Science, Anhui Agricultural University, Hefei, China
| | - Chaoliang Liu
- College of Life Science, Anhui Agricultural University, Hefei, China
| | - Lei Wang
- College of Life Science, Anhui Agricultural University, Hefei, China
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Ku B, You JA, Oh KJ, Yun HY, Lee HS, Shin HC, Jung J, Shin YB, Kim SJ. Crystal structures of two forms of the Acanthamoeba polyphaga mimivirus Rab GTPase. Arch Virol 2017; 162:3407-3416. [PMID: 28779233 DOI: 10.1007/s00705-017-3510-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 06/30/2017] [Indexed: 01/09/2023]
Abstract
Acanthamoeba polyphaga mimivirus (APMV) is a member of the family of giant viruses, harboring a 1,200 kbp genome within its 700 nm-diameter viral particle. The R214 gene of the APMV genome was recently shown to encode a homologue of the Rab GTPases, molecular switch proteins known to play a pivotal role in the regulation of membrane trafficking that were considered to exist only in eukaryotes. Herein, we report the first crystal structures of GDP- and GTP-bound forms of APMV Rab GTPase, both of which were determined at high resolution. An in-depth structural comparison of APMV Rab with each other and with mammalian Rab homologues led to an atomic-level elucidation of the inactive-active conformational change upon GDP/GTP exchange. APMV Rab GTPase exhibited considerable structural similarity to human Rab5, as previously predicted based on its amino acid sequence. However, it also contains unique structural features differentiating it from mammalian homologues, such as the functional substitution of a phenylalanine residue for the stabilization of the nucleotide's guanine base.
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Affiliation(s)
- Bonsu Ku
- Disease Target Structure Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 34141, Republic of Korea.
- Department of Bioscience, University of Science and Technology KRIBB School, Daejeon, 34113, Republic of Korea.
| | - Jin A You
- Disease Target Structure Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 34141, Republic of Korea
- Department of Bioscience, University of Science and Technology KRIBB School, Daejeon, 34113, Republic of Korea
| | - Kyoung-Jin Oh
- Metabolic Regulation Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 34141, Republic of Korea
| | - Hye-Yeoung Yun
- Disease Target Structure Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 34141, Republic of Korea
- Department of Bioscience, University of Science and Technology KRIBB School, Daejeon, 34113, Republic of Korea
| | - Hye Seon Lee
- Disease Target Structure Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 34141, Republic of Korea
- Department of Biology, Chungnam National University, Daejeon, 34134, Republic of Korea
| | - Ho-Chul Shin
- Disease Target Structure Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 34141, Republic of Korea
| | - Juyeon Jung
- Hazard Monitoring BioNanotechnology Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 34141, Republic of Korea
| | - Yong-Beom Shin
- Hazard Monitoring BioNanotechnology Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 34141, Republic of Korea
| | - Seung Jun Kim
- Disease Target Structure Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 34141, Republic of Korea.
- Department of Bioscience, University of Science and Technology KRIBB School, Daejeon, 34113, Republic of Korea.
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Ramadass M, Catz SD. Molecular mechanisms regulating secretory organelles and endosomes in neutrophils and their implications for inflammation. Immunol Rev 2017; 273:249-65. [PMID: 27558339 DOI: 10.1111/imr.12452] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Neutrophils constitute the first line of cellular defense against invading microorganisms and modulate the subsequent innate and adaptive immune responses. In order to execute a rapid and precise response to infections, neutrophils rely on preformed effector molecules stored in a variety of intracellular granules. Neutrophil granules contain microbicidal factors, the membrane-bound components of the respiratory burst oxidase, membrane-bound adhesion molecules, and receptors that facilitate the execution of all neutrophil functions including adhesion, transmigration, phagocytosis, degranulation, and neutrophil extracellular trap formation. The rapid mobilization of intracellular organelles is regulated by vesicular trafficking mechanisms controlled by effector molecules that include small GTPases and their interacting proteins. In this review, we focus on recent discoveries of mechanistic processes that are at center stage of the regulation of neutrophil function, highlighting the discrete and selective pathways controlled by trafficking modulators. In particular, we describe novel pathways controlled by the Rab27a effectors JFC1 and Munc13-4 in the regulation of degranulation, reactive oxygen species and neutrophil extracellular trap production, and endolysosomal signaling. Finally, we discuss the importance of understanding these molecular mechanisms in order to design novel approaches to modulate neutrophil-mediated inflammatory processes in a targeted fashion.
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Affiliation(s)
- Mahalakshmi Ramadass
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Sergio D Catz
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA, USA
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15
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Yang CD, Dang X, Zheng HW, Chen XF, Lin XL, Zhang DM, Abubakar YS, Chen X, Lu G, Wang Z, Li G, Zhou J. Two Rab5 Homologs Are Essential for the Development and Pathogenicity of the Rice Blast Fungus Magnaporthe oryzae. FRONTIERS IN PLANT SCIENCE 2017; 8:620. [PMID: 28529514 PMCID: PMC5418346 DOI: 10.3389/fpls.2017.00620] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2017] [Accepted: 04/06/2017] [Indexed: 06/07/2023]
Abstract
The rice blast fungus, Magnaporthe oryzae, infects many economically important cereal crops, particularly rice. It has emerged as an important model organism for studying the growth, development, and pathogenesis of filamentous fungi. RabGTPases are important molecular switches in regulation of intracellular membrane trafficking in all eukaryotes. MoRab5A and MoRab5B are Rab5 homologs in M. oryzae, but their functions in the fungal development and pathogenicity are unknown. In this study, we have employed a genetic approach and demonstrated that both MoRab5A and MoRab5B are crucial for vegetative growth and development, conidiogenesis, melanin synthesis, vacuole fusion, endocytosis, sexual reproduction, and plant pathogenesis in M. oryzae. Moreover, both MoRab5A and MoRab5B show similar localization in hyphae and conidia. To further investigate possible functional redundancy between MoRab5A and MoRab5B, we overexpressed MoRAB5A and MoRAB5B, respectively, in MoRab5B:RNAi and MoRab5A:RNAi strains, but neither could rescue each other's defects caused by the RNAi. Taken together, we conclude that both MoRab5A and MoRab5B are necessary for the development and pathogenesis of the rice blast fungus, while they may function independently.
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Affiliation(s)
- Cheng D. Yang
- Fujian Province Key Laboratory of Pathogenic Fungi and Mycotoxins and College of Life Sciences, Fujian Agriculture and Forestry UniversityFuzhou, China
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry UniversityFuzhou, China
| | - Xie Dang
- Fujian Province Key Laboratory of Pathogenic Fungi and Mycotoxins and College of Life Sciences, Fujian Agriculture and Forestry UniversityFuzhou, China
| | - Hua W. Zheng
- Fujian Province Key Laboratory of Pathogenic Fungi and Mycotoxins and College of Life Sciences, Fujian Agriculture and Forestry UniversityFuzhou, China
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry UniversityFuzhou, China
| | - Xiao F. Chen
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry UniversityFuzhou, China
| | - Xiao L. Lin
- Fujian Province Key Laboratory of Pathogenic Fungi and Mycotoxins and College of Life Sciences, Fujian Agriculture and Forestry UniversityFuzhou, China
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry UniversityFuzhou, China
| | - Dong M. Zhang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry UniversityFuzhou, China
| | - Yakubu S. Abubakar
- Fujian Province Key Laboratory of Pathogenic Fungi and Mycotoxins and College of Life Sciences, Fujian Agriculture and Forestry UniversityFuzhou, China
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry UniversityFuzhou, China
| | - Xin Chen
- Fujian Province Key Laboratory of Pathogenic Fungi and Mycotoxins and College of Life Sciences, Fujian Agriculture and Forestry UniversityFuzhou, China
| | - Guodong Lu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry UniversityFuzhou, China
| | - Zonghua Wang
- Fujian Province Key Laboratory of Pathogenic Fungi and Mycotoxins and College of Life Sciences, Fujian Agriculture and Forestry UniversityFuzhou, China
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry UniversityFuzhou, China
- College of Ocean Science, Minjiang UniversityFuzhou, China
| | - Guangpu Li
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma CityOK, USA
| | - Jie Zhou
- Fujian Province Key Laboratory of Pathogenic Fungi and Mycotoxins and College of Life Sciences, Fujian Agriculture and Forestry UniversityFuzhou, China
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry UniversityFuzhou, China
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16
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Jiang Z, Wang H, Zhang G, Zhao R, Bie T, Zhang R, Gao D, Xing L, Cao A. Characterization of a small GTP-binding protein gene TaRab18 from wheat involved in the stripe rust resistance. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2017; 113:40-50. [PMID: 28182966 DOI: 10.1016/j.plaphy.2017.01.025] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 12/27/2016] [Accepted: 01/27/2017] [Indexed: 05/24/2023]
Abstract
The stripe rust resistance gene, Yr26, is commonly used in wheat production. Identification of Yr26 resistance related genes is important for better understanding of the resistance mechanism. TaRab18, a putative small GTP-binding protein, was screened as a resistance regulated gene as it showed differential expression between the Yr26-containing resistant wheat and the susceptible wheat at different time points after Pst inoculation. TaRab18 contains four typical domains (GI to GIV) of the small GTP-binding proteins superfamily and five domains (RabF1 to RabF5) specific to the Rab subfamily. From the phylogenetic tree that TaRab18 was identified as belonging to the RABC1 subfamily. Chromosome location analysis indicated that TaRab18 and its homeoalles were on the homeologous group 7 chromosomes, and the Pst induced TaRab18 was on the 7 B chromosome. Functional analysis by virus induced gene silencing (VIGS) indicated that TaRab18 was positively involved in the stripe rust resistance through regulating the hypersensitive response, and Pst can develop on the leaves of TaRab18 silenced 92R137. However, over-expression of TaRab18 in susceptible Yangmai158 did not enhance its resistance dramatically, only from 9 grade in Yangmai158 to 8 grade in the transgenic plant. However, histological observation indicated that the transgenic plants with over-expressed TaRab18 showed a strong hypersensitive response at the early infection stage. The research herein, will improve our understanding of the roles of Rab in wheat resistance.
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Affiliation(s)
- Zhengning Jiang
- Key Laboratory of Crop Genetics and Germplasm Enhancement, Cytogenetics Institute, Nanjing Agricultural University/JCIC-MCP, Nanjing 210095, China; Key Laboratory of Wheat Biology and Genetic Improvement on Low and Middle Yangtze River Valley Wheat Region (Ministry of Agriculture), Institute of Agricultural Science of the Lixiahe District in Jiangsu Province, Yangzhou 225007, China.
| | - Hui Wang
- Key Laboratory of Crop Genetics and Germplasm Enhancement, Cytogenetics Institute, Nanjing Agricultural University/JCIC-MCP, Nanjing 210095, China.
| | - Guoqin Zhang
- Key Laboratory of Crop Genetics and Germplasm Enhancement, Cytogenetics Institute, Nanjing Agricultural University/JCIC-MCP, Nanjing 210095, China.
| | - Renhui Zhao
- Key Laboratory of Wheat Biology and Genetic Improvement on Low and Middle Yangtze River Valley Wheat Region (Ministry of Agriculture), Institute of Agricultural Science of the Lixiahe District in Jiangsu Province, Yangzhou 225007, China.
| | - Tongde Bie
- Key Laboratory of Wheat Biology and Genetic Improvement on Low and Middle Yangtze River Valley Wheat Region (Ministry of Agriculture), Institute of Agricultural Science of the Lixiahe District in Jiangsu Province, Yangzhou 225007, China.
| | - Ruiqi Zhang
- Key Laboratory of Crop Genetics and Germplasm Enhancement, Cytogenetics Institute, Nanjing Agricultural University/JCIC-MCP, Nanjing 210095, China.
| | - Derong Gao
- Key Laboratory of Wheat Biology and Genetic Improvement on Low and Middle Yangtze River Valley Wheat Region (Ministry of Agriculture), Institute of Agricultural Science of the Lixiahe District in Jiangsu Province, Yangzhou 225007, China.
| | - Liping Xing
- Key Laboratory of Crop Genetics and Germplasm Enhancement, Cytogenetics Institute, Nanjing Agricultural University/JCIC-MCP, Nanjing 210095, China.
| | - Aizhong Cao
- Key Laboratory of Crop Genetics and Germplasm Enhancement, Cytogenetics Institute, Nanjing Agricultural University/JCIC-MCP, Nanjing 210095, China.
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17
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Zheng H, Zheng W, Wu C, Yang J, Xi Y, Xie Q, Zhao X, Deng X, Lu G, Li G, Ebbole D, Zhou J, Wang Z. Rab GTPases are essential for membrane trafficking-dependent growth and pathogenicity in Fusarium graminearum. Environ Microbiol 2015; 17:4580-99. [PMID: 26177389 DOI: 10.1111/1462-2920.12982] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2015] [Revised: 07/06/2015] [Accepted: 07/07/2015] [Indexed: 12/12/2022]
Abstract
Rab GTPases represent the largest subfamily of Ras-related small GTPases and regulate membrane trafficking. Vesicular transport is a general mechanism that governs intracellular membrane trafficking along the endocytic and exocytic pathways in all eukaryotic cells. Fusarium graminearum is a filamentous fungus and causes the devastating and economically important head blight of wheat and related species. The mechanism of vesicular transport is not well understood, and little is known about Rab GTPases in F. graminearum. In this study, we systematically characterized all eleven FgRabs by live cell imaging and genetic analysis. We find that FgRab51 and FgRab52 are important for the endocytosis, FgRab7 localizes to the vacuolar membrane and regulates the fusion of vacuoles and autophagosomes, and FgRab8 and FgRab11 are important for polarized growth and/or exocytosis. Furthermore, both endocytic and exocytic FgRabs are required for vegetative growth, conidiogenesis, sexual reproduction, as well as pathogenesis and deoxynivalenol metabolism in F. graminearum. Thus, we conclude that Rab GTPases are essential for membrane trafficking-dependent growth and pathogenicity in F. graminearum.
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Affiliation(s)
- Huawei Zheng
- Fujian Province Key Laboratory of Pathogenic Fungi and Mycotoxins, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China.,Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Wenhui Zheng
- Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Congxian Wu
- Fujian Province Key Laboratory of Pathogenic Fungi and Mycotoxins, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Jie Yang
- Institute of Forestry Protection, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Yang Xi
- Fujian Province Key Laboratory of Pathogenic Fungi and Mycotoxins, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Qiurong Xie
- Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Xu Zhao
- Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Xiaolong Deng
- Fujian Province Key Laboratory of Pathogenic Fungi and Mycotoxins, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Guodong Lu
- Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Guangpu Li
- Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, Fuzhou, China.,Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Daniel Ebbole
- Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, Fuzhou, China.,Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX, USA
| | - Jie Zhou
- Fujian Province Key Laboratory of Pathogenic Fungi and Mycotoxins, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China.,Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Zonghua Wang
- Fujian Province Key Laboratory of Pathogenic Fungi and Mycotoxins, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China.,Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, Fuzhou, China
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18
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Watson K, Rossi G, Temple B, Brennwald P. Structural basis for recognition of the Sec4 Rab GTPase by its effector, the Lgl/tomosyn homologue, Sro7. Mol Biol Cell 2015. [PMID: 26202462 PMCID: PMC4569318 DOI: 10.1091/mbc.e15-04-0228] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Members of the tomosyn/Lgl/Sro7 family play important roles in vesicle trafficking and cell polarity in eukaryotic cells. The yeast homologue, Sro7, is believed to act as a downstream effector of the Sec4 Rab GTPase to promote soluble N-ethylmaleimide-sensitive factor adaptor protein receptor (SNARE) assembly during Golgi-to-cell surface vesicle transport. Here we describe the identification of a Sec4 binding site on the surface of Sro7 that is contained within a cleft created by the junction of two adjacent β-propellers that form the core structure of Sro7. Computational docking experiments suggested four models for interaction of GTP-Sec4 with the Sro7 binding cleft. Further mutational and biochemical analyses confirmed that only one of the four docking arrangements is perfectly consistent with our genetic and biochemical interaction data. Close examination of this docking model suggests a structural basis for the high substrate and nucleotide selectivity in effector binding by Sro7. Finally, analysis of the surface variation within the homologous interaction site on tomosyn-1 and Lgl-1 structural models suggests a possible conserved Rab GTPase effector function in tomosyn vertebrate homologues.
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Affiliation(s)
- Kelly Watson
- Department of Cell Biology and Physiology, University of North Carolina School of Medicine, Chapel Hill, NC 27599 Graduate Program in Cell and Developmental Biology, University of North Carolina School of Medicine, Chapel Hill, NC 27599
| | - Guendalina Rossi
- Department of Cell Biology and Physiology, University of North Carolina School of Medicine, Chapel Hill, NC 27599
| | - Brenda Temple
- Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill, NC 27599 R. L. Juliano Structural Bioinformatics Core, University of North Carolina School of Medicine, Chapel Hill, NC 27599
| | - Patrick Brennwald
- Department of Cell Biology and Physiology, University of North Carolina School of Medicine, Chapel Hill, NC 27599 Graduate Program in Cell and Developmental Biology, University of North Carolina School of Medicine, Chapel Hill, NC 27599
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19
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Ye M, Chen Y, Zou S, Yu S, Liang Y. Ypt1 suppresses defects of vesicle trafficking and autophagy in Ypt6 related mutants. Cell Biol Int 2015; 38:663-74. [PMID: 24843892 DOI: 10.1002/cbin.10250] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Ypt/Rab GTPases coordinately regulate vesicle trafficking in yeasts. Previously, Ypt1 was shown to suppress growth defects of Ypt6 and its related mutants (ypt6ts, ric1∆, rgp1∆, ric1∆rgp1∆), but the physiological role of this suppression has not been well studied. We have investigated the effects of Ypt1 on two major trafficking pathways, vesicle trafficking and autophagy, in Ypt6 related mutants. Ypt1 restores Snc1 transport to the plasma membrane via Golgi in the exocytic pathway in Ypt6 related mutants under nutrient rich conditions. Overexpression of Ypt1 suppresses autophagic defects under nutrient starvation conditions with increased GFP-Atg8 sorting to vacuoles and GFP-Atg8 to GFP conversion in Ypt6 related mutants. However, overexpression of Ypt1 does not restore Ypt6 intracellular localisation in rgp1∆ cells. We propose that vesicle trafficking and autophagy are closely connected processes, and Ypt1 and Ypt6 have some similar functions in both cellular processes.
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20
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Lardong JA, Driller JH, Depner H, Weise C, Petzoldt A, Wahl MC, Sigrist SJ, Loll B. Structures of Drosophila melanogaster Rab2 and Rab3 bound to GMPPNP. Acta Crystallogr F Struct Biol Commun 2015; 71:34-40. [PMID: 25615965 PMCID: PMC4304744 DOI: 10.1107/s2053230x1402617x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 11/28/2014] [Indexed: 01/11/2023] Open
Abstract
Rab GTPases belong to the large family of Ras proteins. They act as key regulators of membrane organization and intracellular trafficking. Functionally, they act as switches. In the active GTP-bound form they can bind to effector proteins to facilitate the delivery of transport vesicles. Upon stimulation, the GTP is hydrolyzed and the Rab proteins undergo conformational changes in their switch regions. This study focuses on Rab2 and Rab3 from Drosophila melanogaster. Whereas Rab2 is involved in vesicle transport between the Golgi and the endoplasmatic reticulum, Rab3 is a key player in exocytosis, and in the synapse it is involved in the assembly of the presynaptic active zone. Here, high-resolution crystal structures of Rab2 and Rab3 in complex with GMPPNP and Mg2+ are presented. In the structure of Rab3 a modified cysteine residue is observed with an enigmatic electron density attached to its thiol function.
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Affiliation(s)
- Jennifer A. Lardong
- Institut für Chemie und Biochemie Abteilung Strukturbiochemie, Freie Universität Berlin, Takustrasse 6, 15195 Berlin, Germany
| | - Jan H. Driller
- Institut für Chemie und Biochemie Abteilung Strukturbiochemie, Freie Universität Berlin, Takustrasse 6, 15195 Berlin, Germany
| | - Harald Depner
- Biologie Abteilung Genetik, Freie Universität Berlin, Takustrasse 6, 15195 Berlin, Germany
- NeuroCure Cluster of Excellence, Charité Universitätsmedizin Berlin, Virchowweg 6, 10117 Berlin, Germany
| | - Christoph Weise
- Institut für Chemie und Biochemie, BioSupraMol Core Facility, Freie Universität Berlin, Thielallee 63, 15195 Berlin, Germany
| | - Astrid Petzoldt
- Biologie Abteilung Genetik, Freie Universität Berlin, Takustrasse 6, 15195 Berlin, Germany
- NeuroCure Cluster of Excellence, Charité Universitätsmedizin Berlin, Virchowweg 6, 10117 Berlin, Germany
| | - Markus C. Wahl
- Institut für Chemie und Biochemie Abteilung Strukturbiochemie, Freie Universität Berlin, Takustrasse 6, 15195 Berlin, Germany
| | - Stephan J. Sigrist
- Biologie Abteilung Genetik, Freie Universität Berlin, Takustrasse 6, 15195 Berlin, Germany
- NeuroCure Cluster of Excellence, Charité Universitätsmedizin Berlin, Virchowweg 6, 10117 Berlin, Germany
| | - Bernhard Loll
- Institut für Chemie und Biochemie Abteilung Strukturbiochemie, Freie Universität Berlin, Takustrasse 6, 15195 Berlin, Germany
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21
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Rajan N, Agarwal P, Patel K, Sanadhya P, Khedia J, Agarwal PK. Molecular characterization and identification of target protein of an important vesicle trafficking gene AlRab7 from a salt excreting halophyte Aeluropus lagopoides. DNA Cell Biol 2014; 34:83-91. [PMID: 25408252 DOI: 10.1089/dna.2014.2592] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The endomembrane system plays an important role during cellular adaptation of the plants with the extracellular environment. The small GTP-binding protein Rab7 located at the vacuolar membrane regulates the vesicle fusion with the vacuole and thereby helps in recycling of the molecules. This is the first report on isolation and characterization of AlRab7 gene from the halophyte plant, Aeluropus that extrudes NaCl through salt glands and grows luxuriantly throughout the year at the Gujarat coast, India. The AlRab7 encodes a protein with 206 amino acids, and a highly conserved effector-binding domain and four nucleotide-binding domains. The in silico analysis predicts the presence of the prenylation site for Rab geranylgeranyltransferase 2 and the Rab escort protein site. The C-terminal two cysteine residues in -XCC sequence are present for membrane attachment. Transcript expression of the AlRab7 gene was differentially regulated by different environmental stimuli such as dehydration, salinity, and hormone abscisic acid (ABA). The recombinant Escherichia coli cells showed improved growth in Luria Bertani medium supplemented with NaCl, KCl, mannitol, ABA, and indole-3-acetic acid. A novel Rab7 interacting partner AlRabring7 was identified by yeast two-hybrid screening.
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Affiliation(s)
- Navya Rajan
- 1 Discipline of Wasteland Research, CSIR-Central Salt and Marine Chemicals Research Institute, Bhavnagar, India
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22
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Rab proteins: the key regulators of intracellular vesicle transport. Exp Cell Res 2014; 328:1-19. [PMID: 25088255 DOI: 10.1016/j.yexcr.2014.07.027] [Citation(s) in RCA: 190] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Revised: 07/06/2014] [Accepted: 07/23/2014] [Indexed: 01/01/2023]
Abstract
Vesicular/membrane trafficking essentially regulates the compartmentalization and abundance of proteins within the cells and contributes in many signalling pathways. This membrane transport in eukaryotic cells is a complex process regulated by a large and diverse array of proteins. A large group of monomeric small GTPases; the Rabs are essential components of this membrane trafficking route. Most of the Rabs are ubiquitously expressed proteins and have been implicated in vesicle formation, vesicle motility/delivery along cytoskeleton elements and docking/fusion at target membranes through the recruitment of effectors. Functional impairments of Rabs affecting transport pathways manifest different diseases. Rab functions are accompanied by cyclical activation and inactivation of GTP-bound and GDP-bound forms between the cytosol and membranes which is regulated by upstream regulators. Rab proteins are characterized by their distinct sub-cellular localization and regulate a wide variety of endocytic, transcytic and exocytic transport pathways. Mutations of Rabs affect cell growth, motility and other biological processes.
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23
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New putative chloroplast vesicle transport components and cargo proteins revealed using a bioinformatics approach: an Arabidopsis model. PLoS One 2013; 8:e59898. [PMID: 23573218 PMCID: PMC3613420 DOI: 10.1371/journal.pone.0059898] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Accepted: 02/19/2013] [Indexed: 11/23/2022] Open
Abstract
Proteins and lipids are known to be transported to targeted cytosolic compartments in vesicles. A similar system in chloroplasts is suggested to transfer lipids from the inner envelope to the thylakoids. However, little is known about both possible cargo proteins and the proteins required to build a functional vesicle transport system in chloroplasts. A few components have been suggested, but only one (CPSAR1) has a verified location in chloroplast vesicles. This protein is localized in the donor membrane (envelope) and vesicles, but not in the target membrane (thylakoids) suggesting it plays a similar role to a cytosolic homologue, Sar1, in the secretory pathway. Thus, we hypothesized that there may be more similarities, in addition to lipid transport, between the vesicle transport systems in the cytosol and chloroplast, i.e. similar vesicle transport components, possible cargo proteins and receptors. Therefore, using a bioinformatics approach we searched for putative chloroplast components in the model plant Arabidopsis thaliana, corresponding mainly to components of the cytosolic vesicle transport system that may act in coordination with previously proposed COPII chloroplast homologues. We found several additional possible components, supporting the notion of a fully functional vesicle transport system in chloroplasts. Moreover, we found motifs in thylakoid-located proteins similar to those of COPII vesicle cargo proteins, supporting the hypothesis that chloroplast vesicles may transport thylakoid proteins from the envelope to the thylakoid membrane. Several putative cargo proteins are involved in photosynthesis, thus we propose the existence of a novel thylakoid protein pathway that is important for construction and maintenance of the photosynthetic machinery.
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Amicucci A, Balestrini R, Kohler A, Barbieri E, Saltarelli R, Faccio A, Roberson RW, Bonfante P, Stocchi V. Hyphal and cytoskeleton polarization in Tuber melanosporum: A genomic and cellular analysis. Fungal Genet Biol 2011; 48:561-72. [DOI: 10.1016/j.fgb.2010.12.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2010] [Revised: 12/04/2010] [Accepted: 12/07/2010] [Indexed: 10/18/2022]
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25
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Murphy JP, Pinto DM. Temporal proteomic analysis of IGF-1R signalling in MCF-7 breast adenocarcinoma cells. Proteomics 2010; 10:1847-60. [PMID: 20213678 DOI: 10.1002/pmic.200900711] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Dysregulation of the insulin-like growth factor 1 receptor signalling network is implicated in tumour growth and resistance to chemotherapy. We explored proteomic changes resulting from insulin-like growth factor 1 stimulation of MCF-7 adenocarcinoma cells as a function of time. Quantitative analysis using iTRAQ reagents and 2-D LC-MS/MS analysis of three biological replicates resulted in the identification of 899 proteins (p<or=0.05) with an estimated mean false-positive rate of 2.6%. Quantitative protein expression was obtained from 681 proteins. Further analysis by supervised k-means clustering identified five temporal clusters, which were submitted to the FuncAssociate server to assign overrepresented gene ontology terms. Proteins associated with vesicle transport were significantly overrepresented. We further analyzed our data set for proteins showing temporal significance using the software, extraction and analysis of differential gene expression, resulting in 20 significantly and temporally changing proteins (p<or=0.1). These significant proteins play roles in, among others, altered glucose metabolism (lactate dehydrogenase A and pyruvate kinase M1/M2) and cellular stress (nascent polypeptide-associated complex subunit alpha and heat shock (HSC70) proteins). We used multiple reaction monitoring to validate these interesting proteins and have revealed several differences in relative peptide expression corresponding to protein isoforms and variants.
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Affiliation(s)
- J Patrick Murphy
- Department of Biology, Dalhousie University, Halifax, NS, Canada
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27
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Sheltzer JM, Rose MD. The class V myosin Myo2p is required for Fus2p transport and actin polarization during the yeast mating response. Mol Biol Cell 2009; 20:2909-19. [PMID: 19403698 DOI: 10.1091/mbc.e08-09-0923] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Mating yeast cells remove their cell walls and fuse their plasma membranes in a spatially restricted cell contact region. Cell wall removal is dependent on Fus2p, an amphiphysin-associated Rho-GEF homolog. As mating cells polarize, Fus2p-GFP localizes to the tip of the mating projection, where cell fusion will occur, and to cytoplasmic puncta, which show rapid movement toward the tip. Movement requires polymerized actin, whereas tip localization is dependent on both actin and a membrane protein, Fus1p. Here, we show that Fus2p-GFP movement is specifically dependent on Myo2p, a type V myosin, and not on Myo4p, another type V myosin, or Myo3p and Myo5p, type I myosins. Fus2p-GFP tip localization and actin polarization in shmoos are also dependent on Myo2p. A temperature-sensitive tropomyosin mutation and Myo2p alleles that specifically disrupt vesicle binding caused rapid loss of actin patch organization, indicating that transport is required to maintain actin polarity. Mutant shmoos lost actin polarity more rapidly than mitotic cells, suggesting that the maintenance of cell polarity in shmoos is more sensitive to perturbation. The different velocities, differential sensitivity to mutation and lack of colocalization suggest that Fus2p and Sec4p, another Myo2p cargo associated with exocytotic vesicles, reside predominantly on different cellular organelles.
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Affiliation(s)
- Jason M Sheltzer
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544-1014, USA
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Bhuin T, Roy JK. Rab11 is required for myoblast fusion in Drosophila. Cell Tissue Res 2009; 336:489-99. [PMID: 19370361 DOI: 10.1007/s00441-009-0782-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2008] [Accepted: 02/11/2009] [Indexed: 01/06/2023]
Abstract
Rab11, an evolutionarily conserved, ubiquitously expressed subfamily of small monomeric Rab GTPases, has been implicated in regulating vesicular trafficking through the recycling of endosomal compartment. In order to gain an insight into the role of this gene in myogenesis during embryonic development, we have studied the expression pattern of Rab11 in mesoderm during muscle differentiation in Drosophila embryo. When dominant-negative or constitutively active Drosophila Rab11 proteins are expressed or Rab11 is reduced via double-stranded RNA in muscle precursors, they cause partial failure of myoblast fusion and show anomalies in the shape of the muscle fibres. Our results suggest that Rab11 plays no role in cell fate specification in muscle precursors but is required late in the process of myoblast fusion.
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Affiliation(s)
- Tanmay Bhuin
- Cytogenetics Laboratory, Department of Zoology, Banaras Hindu University, Varanasi, 221 005, India
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Chapter 5: rab proteins and their interaction partners. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2009; 274:235-74. [PMID: 19349039 DOI: 10.1016/s1937-6448(08)02005-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The Ras superfamily consists of over 150 low molecular weight proteins that cycle between an inactive guanosine diphosphate (GDP)-bound state and an active guanosine triphosphate (GTP)-bound state. They are involved in a variety of signal transduction pathways that regulate cell growth, intracellular trafficking, cell migration, and apoptosis. Several methods have been devised to detect and characterize the interacting partners of small GTPases with the aim of better understanding their physiological function in normal cells and tumor cells. The Rab (Ras analog in brain) proteins form the largest family within the Ras superfamily. Rab proteins regulate vesicular trafficking pathways, behaving as membrane-associated molecular switches. The guanine nucleotide-binding status of Rab proteins is modulated by three different classes of regulatory proteins, which have been extensively studied for the Rab molecules but also for other subfamilies of the Ras superfamily. Furthermore, numerous effector molecules have been isolated especially for the Rab subfamily of proteins, which interact via a Rab-binding domain (RBD) and are recruited afterwards to specific sub-cellular compartments by the Rab proteins.
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Dejgaard SY, Murshid A, Erman A, Kızılay O, Verbich D, Lodge R, Dejgaard K, Ly-Hartig TBN, Pepperkok R, Simpson JC, Presley JF. Rab18 and Rab43 have key roles in ER-Golgi trafficking. J Cell Sci 2008; 121:2768-81. [DOI: 10.1242/jcs.021808] [Citation(s) in RCA: 139] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Rabs and Arfs/Arls are Ras-related small GTPases of particular relevance to membrane trafficking. It is thought that these proteins regulate specific pathways through interactions with coat, motor, tether and SNARE proteins. We screened a comprehensive list of Arf/Arl/Rab proteins, previously identified on purified Golgi membranes by a proteomics approach (37 in total), for Golgi or intra-Golgi localization, dominant-negative and overexpression phenotypes. Further analysis of two of these proteins, Rab18 and Rab43, strongly indicated roles in ER-Golgi trafficking. Rab43-T32N redistributed Golgi elements to ER exit sites without blocking trafficking of the secretory marker VSVG-GFP from ER to cell surface. Wild-type Rab43 redistributes the p150Glued subunit of dynactin, consistent with a specific role in regulating association of pre-Golgi intermediates with microtubules. Overexpression of wild-type GFP-Rab18 or incubation with any of three siRNAs directed against Rab18 severely disrupts the Golgi complex and reduces secretion of VSVG. Rab18 mutants specifically enhance retrograde Golgi-ER transport of the COPI-independent cargo β-1,4-galactosyltransferase (Galtase)-YFP but not the COPI-dependent cargo p58-YFP from the Golgi to ER in a photobleach assay. Rab18-S22N also potentiated brefeldin-A-induced ER-Golgi fusion. This study is the first comprehensive application of large-scale proteomics to the cell biology of small GTPases of the secretory pathway.
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Affiliation(s)
- Selma Y. Dejgaard
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada, H3A 2B2
| | - Ayesha Murshid
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada, H3A 2B2
| | - Ayşegül Erman
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada, H3A 2B2
| | - Özge Kızılay
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada, H3A 2B2
| | - David Verbich
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada, H3A 2B2
| | - Robert Lodge
- Laboratoire d'Immunoretrovirologie, Centre de Recherche d'Infectiologie – CHUL, Quebec, Canada, G1V 4G2
| | - Kurt Dejgaard
- Department of Biochemistry, McGill University, Montreal, Quebec, Canada, H3G 1Y6
| | | | - Rainer Pepperkok
- Cell Biology and Biophysics Unit, EMBL, 69117 Heidelberg, Germany
| | | | - John F. Presley
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada, H3A 2B2
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Cai H, Reinisch K, Ferro-Novick S. Coats, tethers, Rabs, and SNAREs work together to mediate the intracellular destination of a transport vesicle. Dev Cell 2007; 12:671-82. [PMID: 17488620 DOI: 10.1016/j.devcel.2007.04.005] [Citation(s) in RCA: 501] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Tethering factors have been shown to interact with Rabs and SNAREs and, more recently, with coat proteins. Coat proteins are required for cargo selection and membrane deformation to bud a transport vesicle from a donor compartment. It was once thought that a vesicle must uncoat before it recognizes its target membrane. However, recent findings have revealed a role for the coat in directing a vesicle to its correct intracellular destination. In this review we will discuss the literature that links coat proteins to vesicle targeting events.
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Affiliation(s)
- Huaqing Cai
- Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT 06519, USA
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33
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Tang WY, Wang L, Li C, Hu ZB, Chen R, Zhu YJ, Shen HB, Wei QY, Zhou JW. Identification and functional characterization of JWA polymorphisms and their association with risk of gastric cancer and esophageal squamous cell carcinoma in a Chinese population. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2007; 70:885-94. [PMID: 17479402 DOI: 10.1080/15287390701285915] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Recently, a novel single nucleotide polymorphism (SNP) in the promoter of the JWA gene (-76G --> C) was identified that may alter the transcription activity and thus play a role in increased risk of bladder cancer. In this study, a screen for more novel variants in the JWA exons was undertaken by using polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) followed by a PCR-restriction fragment length polymorphism (PCR-RFLP) method and evaluating the functions of newl identified JWA -76G --> C using the reporter gene assay. In addition to the -76G --> C polymorphism, another novel SNP (723T --> G) in exon 3 of JWA was identified. In a case-control study of these two SNPs in 413 gastric cancer and 250 esophageal squamous-cell carcinoma (ESCC) patients and 814 cancer-free controls in a Chinese population, data showed that both SNPs were associated with enhanced risk of these cancers. The reporter gene assay showed that the -76C variant allele lost its response to benzo[a]pyrene (BaP) exposure, compared to the -76G allele. In addition, the JWA -76C allele was found to be associated with increased gastric and esophageal cancer risks in this study population. Further studies are needed to substantiate the biological significance and related mechanisms underlying the associations.
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Affiliation(s)
- Wei-Yan Tang
- Department of Molecular Cell Biology and Toxicology, School of Public Health, Nanjing Medical University, China
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34
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Li CP, Zhu YJ, Chen R, Wu W, Li AP, Liu J, Liu QZ, Wei QY, Zhang ZD, Zhou JW. Functional polymorphisms of JWA gene are associated with risk of bladder cancer. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2007; 70:876-84. [PMID: 17479401 DOI: 10.1080/15287390701285824] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The JWA gene is a novel cell differentiation-related gene thought to be a responsive gene in response to DNA damage and repair induced by environmental stressors. Recently, a novel single nucleotide polymorphism (SNP) was identified in the promoter of the JWA gene (-76GC) that may alter the transcription activity and thus play a role in increased risk of bladder cancer. Further, studies were conducted to screen for more novel variants in the JWA exons by using PCR-SSCP (polymerase chain reaction-single-strand conformation polymorphism) followed by PCR-RFLP (PCR restriction fragment length polymorphism) methods. Finally, the functional relevance of the newly identified genetic variants in a hospital-based case-control study of 215 bladder cancer patients and 250 cancer-free controls was evaluated. In addition to the -76GC polymorphism, another novel SNP (454CA in exon2 and 723TG in exon 3) of JWA was identified. The -76GC allele and genotype frequencies were found to vary in different ethnic groups. The -76C allele and 454A allele were both associated with significantly increased risk of bladder cancer. In contrast, the 723GG genotype was associated with a decreased risk of bladder cancer. Furthermore, -76C and 454A together increased the risk of bladder caner using haplotype and stratification analysis. In conclusion, the three novel functional genetic polymorphisms of JWA gene, -76GC, 454CA, and 723TG, appear to contribute to the etiology of bladder cancer.
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Affiliation(s)
- Chun-Ping Li
- Department of Molecular Cell Biology and Toxicology, School of Public Health, Nanjing Medical University, China
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35
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Sato Y, Fukai S, Ishitani R, Nureki O. Crystal structure of the Sec4p.Sec2p complex in the nucleotide exchanging intermediate state. Proc Natl Acad Sci U S A 2007; 104:8305-10. [PMID: 17488829 PMCID: PMC1895945 DOI: 10.1073/pnas.0701550104] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2007] [Indexed: 11/18/2022] Open
Abstract
Vesicular transport during exocytosis is regulated by Rab GTPase (Sec4p in yeast), which is activated by a guanine nucleotide exchange factor (GEF) called Sec2p. Here, we report the crystal structure of the Sec2p GEF domain in a complex with the nucleotide-free Sec4p at 2.7 A resolution. Upon complex formation, the Sec2p helices approach each other, flipping the side chain of Phe-109 toward Leu-104 and Leu-108 of Sec2p. These three residues provide a hydrophobic platform to attract the side chains of Phe-49, Ile-53, and Ile-55 in the switch I region as well as Phe-57 and Trp-74 in the interswitch region of Sec4p. Consequently, the switch I and II regions are largely deformed, to create a flat hydrophobic interface that snugly fits the surface of the Sec2p coiled coil. These drastic conformational changes disrupt the interactions between switch I and the bound guanine nucleotide, which facilitates the GDP release. Unlike the recently reported 3.3 A structure of the Sec4p.Sec2p complex, our structure contains a phosphate ion bound to the P-loop, which may represent an intermediate state of the nucleotide exchange reaction.
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Affiliation(s)
- Yusuke Sato
- *Department of Biological Information, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama-shi, Kanagawa 226-8501, Japan; and
| | - Shuya Fukai
- *Department of Biological Information, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama-shi, Kanagawa 226-8501, Japan; and
- Center for Biological Resources and Informatics, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama-shi, Kanagawa 226-8501, Japan
| | - Ryuichiro Ishitani
- *Department of Biological Information, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama-shi, Kanagawa 226-8501, Japan; and
| | - Osamu Nureki
- *Department of Biological Information, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama-shi, Kanagawa 226-8501, Japan; and
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Rosing M, Ossendorf E, Rak A, Barnekow A. Giantin interacts with both the small GTPase Rab6 and Rab1. Exp Cell Res 2007; 313:2318-25. [PMID: 17475246 DOI: 10.1016/j.yexcr.2007.03.031] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2006] [Revised: 03/16/2007] [Accepted: 03/27/2007] [Indexed: 01/21/2023]
Abstract
The interaction of small GTPases of the Rab family and coiled coil proteins of the golgin family has been reported for example for the Rab1 GTPase and p115, GM130 and Giantin. We now show that Rab6A, a GTPase that controls retrograde trafficking within the Golgi back to the endoplasmic reticulum is also able to bind to Giantin in vivo and in vitro pointing to an interesting complex formation between Giantin and two different Rab GTPases. In Saccharomyces cerevisiae a genetic interaction between Ypt1 and Ypt6 has already been demonstrated, but in this paper we were able to describe that the mammalian Rab GTPases are able to interact on the same golgin protein, Giantin.
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Affiliation(s)
- Mechthild Rosing
- University of Muenster, Department of Experimental Tumorbiology, University of Muenster, Badestr 9, Muenster, Germany
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37
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Poteryaev D, Fares H, Bowerman B, Spang A. Caenorhabditis elegans SAND-1 is essential for RAB-7 function in endosomal traffic. EMBO J 2007; 26:301-12. [PMID: 17203072 PMCID: PMC1783445 DOI: 10.1038/sj.emboj.7601498] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2006] [Accepted: 11/16/2006] [Indexed: 11/08/2022] Open
Abstract
The small rab-GTPase RAB-7 acts in endosome and endosome to lysosome traffic. We identified SAND-1 as a protein required for RAB-7 function based on similarities between SAND-1 and RAB-7 RNAi phenotypes. Although the initial uptake of yolk protein in oocytes, or of soluble secreted (ss) GFP in coelomocytes, appeared normal, further transport along the endocytic traffic route was delayed in the absence of SAND-1 function, and yolk proteins failed to reach yolk granules efficiently. Moreover, in coelomocytes, ssGFP and BSA-Texas-Red were endocytosed but not transported to lysosomes. We show that SAND-1 is essential for RAB-7 function at the transition from early to late endosomes, but not for RAB-7 function at lysosomes.
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Affiliation(s)
- Dmitry Poteryaev
- Biozentrum, University of Basel, Klingelbergstrasse, Basel, Switzerland
| | - Hanna Fares
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, AZ, USA
| | - Bruce Bowerman
- Institute of Molecular Biology, University of Oregon, Eugene, OR, USA
| | - Anne Spang
- Biozentrum, University of Basel, Klingelbergstrasse, Basel, Switzerland
- Department of Biochemistry, Biozentrum, University of Basel, Klingelbergstrasse 70, 4056 Basel, Switzerland. Tel.: +41 61 267 2380; Fax: +41 61 267 2148; E-mail:
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38
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Buvelot Frei S, Rahl PB, Nussbaum M, Briggs BJ, Calero M, Janeczko S, Regan AD, Chen CZ, Barral Y, Whittaker GR, Collins RN. Bioinformatic and comparative localization of Rab proteins reveals functional insights into the uncharacterized GTPases Ypt10p and Ypt11p. Mol Cell Biol 2006; 26:7299-317. [PMID: 16980630 PMCID: PMC1592887 DOI: 10.1128/mcb.02405-05] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A striking characteristic of a Rab protein is its steady-state localization to the cytosolic surface of a particular subcellular membrane. In this study, we have undertaken a combined bioinformatic and experimental approach to examine the evolutionary conservation of Rab protein localization. A comprehensive primary sequence classification shows that 10 out of the 11 Rab proteins identified in the yeast (Saccharomyces cerevisiae) genome can be grouped within a major subclass, each comprising multiple Rab orthologs from diverse species. We compared the locations of individual yeast Rab proteins with their localizations following ectopic expression in mammalian cells. Our results suggest that green fluorescent protein-tagged Rab proteins maintain localizations across large evolutionary distances and that the major known player in the Rab localization pathway, mammalian Rab-GDI, is able to function in yeast. These findings enable us to provide insight into novel gene functions and classify the uncharacterized Rab proteins Ypt10p (YBR264C) as being involved in endocytic function and Ypt11p (YNL304W) as being localized to the endoplasmic reticulum, where we demonstrate it is required for organelle inheritance.
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Affiliation(s)
- Stéphanie Buvelot Frei
- Institut für Biochemie, Swiss Federal Institute of Technology (ETH), CH-8093 Zürich, Switzerland
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39
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Proikas-Cezanne T, Gaugel A, Frickey T, Nordheim A. Rab14 is part of the early endosomal clathrin-coated TGN microdomain. FEBS Lett 2006; 580:5241-6. [PMID: 16962593 DOI: 10.1016/j.febslet.2006.08.053] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2006] [Revised: 08/15/2006] [Accepted: 08/24/2006] [Indexed: 11/22/2022]
Abstract
Rab14 localizes to the Golgi/TGN and to early endosomes, but its biological function remains unclear. By structural modeling, we identified Rab14-specific residues and established a close relationship between the Rab2/Rab4/Rab14, Rab11/25 and Rab39 sub-groups within the Rab protein family. By quantitative confocal microscopy and by density centrifugation we show that Rab14 is part of the early endosomal AP-1 microdomain. Overexpression of a dominant-negative Rab14 GTP-binding mutant that solely localizes to the Golgi donor compartment accelerated EGF degradation. We suggest that the AP-1 microdomain represents the interconnecting compartment in which Rab14 vesicles cycle between early endosomes and the Golgi cisternae.
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Affiliation(s)
- Tassula Proikas-Cezanne
- Autophagy Laboratory, Department of Molecular Biology, Institute for Cell Biology, University of Tuebingen, Auf der Morgenstelle 15, 72076 Tuebingen, Germany.
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40
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Abstract
A novel breast cancer cell line (RAO-3) was established by transduction of the Q61L mutant RAS into human mammary epithelial cells that were immortalized with catalytic subunit of telomerase (hTERT). The cells displayed anchorage-independent growth and proliferation, and formed human mammary spindle cell carcinoma when injected into nude mice. Chromosome locus 1q22-23 was partially duplicated and inverted on one of the 3 chromosomes present in the cell line. We report here that mutations of chromosome 1q22-23 locus have resulted in the loss of RAB25 expression in the breast cancer cell line. Transduction of RAB25 into the breast cancer cell line arrests anchorage-independent growth. We have also demonstrated loss of RAB25 in human breast tumor tissue. These data suggest that loss of RAB25 might contribute to tumorigenesis of breast cancer, and RAB25 is likely to be an important factor in the development of breast cancer. RAB25 could be used as biological marker of breast cancer and provides a target for gene replacement therapy.
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MESH Headings
- Animals
- Biomarkers, Tumor/analysis
- Blotting, Western
- Breast Neoplasms/chemistry
- Carcinoma/chemistry
- Cell Line, Tumor
- Chromosomes, Human, Pair 1
- Chromosomes, Human, Pair 3
- DNA-Binding Proteins
- Female
- Gene Expression Regulation, Neoplastic
- Genes, ras
- Glutamine
- Humans
- In Situ Hybridization, Fluorescence
- Leucine
- Mice
- Mice, Nude
- Mutation
- Plasmids
- Reverse Transcriptase Polymerase Chain Reaction
- Telomerase
- Transduction, Genetic
- rab GTP-Binding Proteins/analysis
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Affiliation(s)
- Ji-Ming Cheng
- Division of Hematology and Oncology, Department of Internal Medicine, Southern Illinois University School of Medicine, Springfield, 62794, USA
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41
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Becker CFW, Seidel R, Jahnz M, Bacia K, Niederhausen T, Alexandrov K, Schwille P, Goody RS, Engelhard M. C-Terminal Fluorescence Labeling of Proteins for Interaction Studies on the Single-Molecule Level. Chembiochem 2006; 7:891-5. [PMID: 16607669 DOI: 10.1002/cbic.200500535] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Christian F W Becker
- Max-Planck-Institut für molekulare Physiologie, Physikalische Biochemie, Otto-Hahn Strasse 11, 44227 Dortmund, Germany.
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42
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Crooke A, Diez A, Mason PJ, Bautista JM. Transient silencing of Plasmodium falciparum bifunctional glucose-6-phosphate dehydrogenase- 6-phosphogluconolactonase. FEBS J 2006; 273:1537-46. [PMID: 16689939 DOI: 10.1111/j.1742-4658.2006.05174.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The bifunctional enzyme glucose-6-phosphate dehydrogenase-6-phosphogluconolactonase (G6PD-6PGL) found in Plasmodium falciparum has unique structural and functional characteristics restricted to this genus. This study was designed to examine the effects of RNA-mediated PfG6PD-6PGL gene silencing in cultures of P. falciparum on the expression of parasite antioxidant defense genes at the transcription level. The highest degree of G6PD-6PGL silencing achieved was 86% at the mRNA level, with a recovery to almost normal levels within 24 h, indicating only transient diminished expression of the PfG6PD-6PGL gene. PfG6PD-6PGL silencing caused arrest of the trophozoite stage and enhanced gametocyte formation. In addition, an immediate transcriptional response was shown by thioredoxin reductase suggesting that P. falciparum G6PD-6PGL plays a physiological role in the specific response of the parasite to intracellullar oxidative stress. P. falciparum transfection with an empty DNA vector also promoted intracellular stress, as determined by mRNA up-regulation of antioxidant genes. Collectively, our findings point to an important role for this enzyme in the parasite's infection cycle. The different characteristics of G6PD-6PGL with respect to its homologue in the host make it an ideal target for therapeutic strategies.
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Affiliation(s)
- Almudena Crooke
- Department of Biochemistry and Molecular Biology IV, Universidad Complutense de Madrid, Facultad de Veterinaria, Madrid, Spain
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43
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Leung KF, Baron R, Seabra MC. Thematic review series: Lipid Posttranslational Modifications. Geranylgeranylation of Rab GTPases. J Lipid Res 2006; 47:467-75. [PMID: 16401880 DOI: 10.1194/jlr.r500017-jlr200] [Citation(s) in RCA: 188] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Rab GTPases require special machinery for protein prenylation, which include Rab escort protein (REP) and Rab geranylgeranyl transferase (RGGT). The current model of Rab geranylgeranylation proposes that REP binds Rab and presents it to RGGT. After geranylgeranylation of Rab C-terminal cysteines, REP delivers the prenylated protein to membranes. The REP-like protein Rab GDP dissociation inhibitor (RabGDI) then recycles the prenylated Rab between the membrane and the cytosol. The recent solution of crystal structures of the Rab prenylation machinery has helped to refine this model and provided further insights. The hydrophobic prenyl binding pocket of RGGT and geranylgeranyl transferase type-I (GGT-I) differs from that of farnesyl transferase (FT). A bulky tryptophan residue in FT restricts the size of the pocket, whereas in RGGT and GGT-I, this position is occupied by smaller residues. A highly conserved phenylalanine in REP, which is absent in RabGDI, is critical for the formation of the REP:RGGT complex. Finally, a geranylgeranyl binding site conserved in REP and RabGDI has been identified within helical domain II. The postprenylation events, including the specific targeting of Rabs to target membranes and the requirement for single versus double geranylgeranylation by different Rabs, remain obscure and should be the subject of future studies.
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Affiliation(s)
- Ka Fai Leung
- Molecular and Cellular Medicine, Division of Biomedical Sciences, Imperial College London, London SW7 2AZ, UK
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44
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Itzen A, Bleimling N, Ignatev A, Pylypenko O, Rak A. Purification, crystallization and preliminary X-ray crystallographic analysis of mammalian MSS4-Rab8 GTPase protein complex. Acta Crystallogr Sect F Struct Biol Cryst Commun 2006; 62:113-6. [PMID: 16511278 PMCID: PMC2150963 DOI: 10.1107/s1744309105042995] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2005] [Accepted: 12/22/2005] [Indexed: 05/06/2023]
Abstract
Rab GTPases function as ubiquitous key regulators of membrane-vesicle transport in eukaryotic cells. MSS4 is an evolutionarily conserved protein that binds to exocytotic Rabs and facilitates nucleotide release. The MSS4 protein in complex with nucleotide-free Rab8 GTPase has been purified and crystallized in a form suitable for structure analysis. The crystals belonged to space group P1, with unit-cell parameters a = 40.92, b = 49.85, c = 83.48 A, alpha = 102.88, beta = 97.46, gamma = 90.12 degrees. A complete data set has been collected to 2 A resolution.
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Affiliation(s)
- Aymelt Itzen
- Max-Planck-Institute for Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany
| | - Nathalie Bleimling
- Max-Planck-Institute for Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany
| | - Alexander Ignatev
- Max-Planck-Institute for Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany
| | - Olena Pylypenko
- Max-Planck-Institute for Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany
| | - Alexey Rak
- Max-Planck-Institute for Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany
- Correspondence e-mail:
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Liu SH, Chou WI, Lin SC, Sheu CC, Chang MDT. Molecular genetic manipulation of Pichia pastoris SEC4 governs cell growth and glucoamylase secretion. Biochem Biophys Res Commun 2005; 336:1172-80. [PMID: 16176807 DOI: 10.1016/j.bbrc.2005.08.234] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2005] [Accepted: 08/29/2005] [Indexed: 11/28/2022]
Abstract
We have previously engineered a recombinant Pichia pastoris GS115 transformant, MSPGA-7, harboring seven copies of glucoamylase (GA) fused with modified signal peptide. High yield secretion of GA was achieved as an extra copy of SEC4 was integrated to the transformant. To elucidate the physiological role of SEC4, a dominant-negative mutant of SEC4, SEC4(S28N), was overexpressed under the control of alchohol oxidase 1 (AOX1) promoter in P. pastoris strain MSPGA-7 as well as a set of host cells harboring multi-copy of wild type SEC4. We found that SEC4(S28N) mutation in the key guanine nucleotide binding domain reduced guanine nucleotide binding affinity, hence it blocked the transport of vesicles required for targeting and fusion to the plasma membrane. The inhibitory levels of cell growth and GA secretion were correlated with the dosage of SEC4(S28N) gene. In addition, overexpression of SEC4 driven by AOX1 promoter in MSPGA-7 improved the secretory production of GA, but demonstrated the delay of cell growth by increased gene dosage of SEC4. Interestingly, a limited level of Sec4p did not disturb the cell growth. It was because expression of only one copy of SEC4 resulted in delay of cell growth at an early stage while still maintaining high level Sec4p at long-term incubation. Accordingly, as glyceraldehyde-3-phosphate dehydrogenase promoter was used to substitute AOX1 promoter to drive the SEC4 expression, enhanced GA secretion but not inhibition of cell growth was achieved. Taken together, our results demonstrate that SEC4 is essential for P. pastoris in regulating cell growth and heterologous protein secretion in a dosage-dependent manner.
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Affiliation(s)
- Shi-Hwei Liu
- Institute of Molecular and Cellular Biology, Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan 30013, ROC
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Zhang XM, Walsh B, Mitchell CA, Rowe T. TBC domain family, member 15 is a novel mammalian Rab GTPase-activating protein with substrate preference for Rab7. Biochem Biophys Res Commun 2005; 335:154-61. [PMID: 16055087 DOI: 10.1016/j.bbrc.2005.07.070] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2005] [Accepted: 07/12/2005] [Indexed: 10/25/2022]
Abstract
Ypt/Rabs are Ras-related GTPases that function as key regulators of intracellular vesicular trafficking. Their slow intrinsic rates of GTP hydrolysis are catalyzed by GTPase-activating proteins (GAPs). Ypt/Rab-GAPs constitute a family of proteins that contain a TBC (Tre-2/Bub2/Cdc16) domain. Only three of the 51 family members predicted in the human genome are confirmed Ypt/Rab-GAPs. Here, we report the identification and characterization of a novel mammalian Ypt/Rab-GAP, TBC domain family, member 15 (TBC1D15). TBC1D15 is ubiquitously expressed and localized predominantly to the cytosol. The TBC domain of TBC1D15 exhibits relatively high homology with that of Gyp7p, a yeast Ypt/Rab-GAP. Furthermore, TBC1D15 stimulates the intrinsic GTPase activity of Rab7, and to a lesser extent Rab11, but is essentially inactive towards Rab4 or Rab6. These data increase the number of mammalian TBC domain family members with demonstrated Rab-GAP activity to four, and suggest that TBC1D15 may be involved in Rab7-mediated late endosomal trafficking.
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Affiliation(s)
- Xiang-Ming Zhang
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Vic. 3800, Australia
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47
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Ramos FP, Araripe JR, Urményi TP, Silva R, Cunha e Silva NL, Leite Fontes CF, da Silveira JF, Rondinelli E. Characterization of RAB-like4, the first identified RAB-like protein from Trypanosoma cruzi with GTPase activity. Biochem Biophys Res Commun 2005; 333:808-17. [PMID: 15975556 DOI: 10.1016/j.bbrc.2005.05.183] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2005] [Accepted: 05/26/2005] [Indexed: 11/25/2022]
Abstract
RAB proteins, which belong to the RAS superfamily, regulate exocytic and endocytic pathways of eukaryotic cells, controlling vesicle docking and fusion. Few RAB proteins have been identified in parasites. Molecular markers for cellular compartments are important to studies concerning about the protein traffic in Trypanosoma cruzi, the causal agent of Chagas disease. In this work, we describe the characterization of TcRABL4, the first RAB-like gene identified in T. cruzi (GenBank Accession No.: ), present as a single-copy gene. TcRABL4 contains all five consensus RAB motifs but lacks cysteine residues at the C terminus, which are essential to isoprenylation, an absolute prerequisite for membrane association of these proteins. TcRABL4 is a functional GTPase that is able to bind and hydrolyze GTP, and its gene is transcribed as a single 1.2 kb mRNA in epimastigotes. TcRABL4 appears to be differentially regulated in the three cell forms of the parasite, and the protein is not associated to membranes, unlike other RAB proteins. It is possible that TcRABL4 may be a member of a novel family of small GTPases.
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Affiliation(s)
- Fabiane Pereira Ramos
- Laboratório de Metabolismo Macromolecular Firmino Torres de Castro, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, CCS, Cidade Universitária, Rio de Janeiro 21949-900, Brazil
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48
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Inadome H, Noda Y, Adachi H, Yoda K. Immunoisolaton of the yeast Golgi subcompartments and characterization of a novel membrane protein, Svp26, discovered in the Sed5-containing compartments. Mol Cell Biol 2005; 25:7696-710. [PMID: 16107716 PMCID: PMC1190314 DOI: 10.1128/mcb.25.17.7696-7710.2005] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Golgi apparatus consists of a set of vesicular compartments which are distinguished by their marker proteins. These compartments are physically separated in the Saccharomyces cerevisiae cell. To characterize them extensively, we immunoisolated vesicles carrying either of the SNAREs Sed5 or Tlg2, the markers of the early and late Golgi compartments, respectively, and analyzed the membrane proteins. The composition of proteins was mostly consistent with the position of each compartment in the traffic. We found six uncharacterized but evolutionarily conserved proteins and named them Svp26 (Sed5 compartment vesicle protein of 26 kDa), Tvp38, Tvp23, Tvp18, Tvp15 (Tlg2 compartment vesicle proteins of 38, 23, 18, and 15 kDa), and Gvp36 (Golgi vesicle protein of 36 kDa). The localization of Svp26 in the early Golgi compartment was confirmed by microscopic and biochemical means. Immunoprecipitation indicated that Svp26 binds to itself and a Golgi mannosyltransferase, Ktr3. In the absence of Svp26, a considerable portion of Ktr3 was mislocalized in the endoplasmic reticulum. Our data suggest that Svp26 has a novel role in retention of a subset of membrane proteins in the early Golgi compartments.
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49
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Zhi H, Wang W, Li L, Chai B, Sun Y, Liang A. Cloning and analysis of 16 Rab genes from macronuclear DNA of Euplotes octocarinatus. ACTA ACUST UNITED AC 2005; 16:260-5. [PMID: 16147885 DOI: 10.1080/10425170500087793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Rab proteins belong to the largest family of the Ras superfamily of small GTPase that play an important role in intracellular vesicular traffic. So far, almost 60 members of Rab family have been identified in mammalian cells. To further study the diversity and function of Rab protein in evolution, unicellular protozoa ciliates, Euplotes octocarinatus, were used in this study, Rab genes were screened by PCR method from macronuclear DNA of E. octocarinatus. Sixteen Rab genes were obtained. They share 87.6-99.5% identities. Highly conserved GTP-binding domains were found. There are some hot regions that diverse sharply in these genes as well.
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Affiliation(s)
- Hui Zhi
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, People's Republic of China
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50
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Wright DP, Johansson T, Le Quéré A, Söderström B, Tunlid A. Spatial patterns of gene expression in the extramatrical mycelium and mycorrhizal root tips formed by the ectomycorrhizal fungus Paxillus involutus in association with birch (Betula pendula) seedlings in soil microcosms. THE NEW PHYTOLOGIST 2005; 167:579-96. [PMID: 15998408 DOI: 10.1111/j.1469-8137.2005.01441.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Functional compartmentation of the extramatrical mycelium of ectomycorrhizal (ECM) fungi is considered important for the operation of ECM associations, although the molecular basis is poorly characterized. Global gene expression profiles of mycelium colonizing an ammonium sulphate ((NH4)2SO4) nutrient patch, rhizomorphs and ECM root tips of the Betula pendula-Paxillus involutus association were compared by cDNA microarray analysis. The expression profiles of rhizomorphs and nutrient patch mycelium were similar to each other but distinctly different from that of mycorrhizal tips. Statistical analyses revealed 337 of 1075 fungal genes differentially regulated among these three tissues. Clusters of genes exhibiting distinct expression patterns within specific tissues were identified. Genes implicated in the glutamine synthetase/glutamate synthase (GS/GOGAT) and urea cycles, and the provision of carbon skeletons for ammonium assimilation via beta-oxidation and the glyoxylate cycle, were highly expressed in rhizomorph and nutrient patch mycelium. Genes implicated in vesicular transport, cytoskeleton organization and morphogenesis and protein degradation were also differentially expressed. Differential expression of genes among the extramatrical mycelium and mycorrhizal tips indicates functional specialization of tissues forming ECM associations.
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Affiliation(s)
- Derek P Wright
- Department of Microbial Ecology, Ecology Building, Lund University, Sölvegatan 37, SE-223 62 Lund, Sweden
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