1
|
Biziaev NS, Shuvalov AV, Alkalaeva EZ. HEMK-Like Methyltransferases in the Regulation of Cellular Processes. Mol Biol 2022. [DOI: 10.1134/s0026893322030025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
2
|
Zhang HY, Hou ZH, Zhang Y, Li ZY, Chen J, Zhou YB, Chen M, Fu JD, Ma YZ, Zhang H, Xu ZS. A soybean EF-Tu family protein GmEF8, an interactor of GmCBL1, enhances drought and heat tolerance in transgenic Arabidopsis and soybean. Int J Biol Macromol 2022; 205:462-472. [PMID: 35122805 DOI: 10.1016/j.ijbiomac.2022.01.165] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 01/12/2022] [Accepted: 01/28/2022] [Indexed: 11/28/2022]
Abstract
A soybean elongation factor Tu family (EF-Tu) protein, GmEF8, was determined to interact with GmCBL1, and GmEF8 expression was found to be induced by various abiotic stresses such as drought and heat. An ortholog of GmEF8 was identified in Arabidopsis, a T-DNA knockout line for which exhibited hypersensitivity to drought and heat stresses. Complementation with GmEF8 rescued the sensitivity of the Arabidopsis mutant to drought and heat stresses, and GmEF8 overexpression conferred drought and heat tolerance to transgenic Arabidopsis plants. In soybean, plants with GmEF8-overexpressing hairy roots (OE-GmEF8) exhibited enhanced drought and heat tolerance and had higher proline levels compared to plants with RNAi GmEF8-knockdown hairy roots (MR-GmEF8) and control hairy roots (EV). A number of drought-responsive genes, such as GmRD22 and GmP5CS, were induced in the OE-GmEF8 line compared to MR-GmEF8 and EV under normal growth conditions. These results suggest that GmEF8 has a positive role in regulating drought and heat stresses in Arabidopsis and soybean. This study reveals a potential role of the soybean GmEF8 gene in response to abiotic stresses, providing a foundation for further investigation into the complexities of stress signal transduction pathways.
Collapse
Affiliation(s)
- Hui-Yuan Zhang
- Institute of Crop Science, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing 100081, China
| | - Ze-Hao Hou
- Institute of Crop Science, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing 100081, China.
| | - Yan Zhang
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences (CAAS)/Key Laboratory of Tobacco Biology and Processing, Ministry of Agriculture, Qingdao 266101, China.
| | - Zhi-Yong Li
- SUSTech Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen 518055, China.
| | - Jun Chen
- Institute of Crop Science, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing 100081, China.
| | - Yong-Bin Zhou
- Institute of Crop Science, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing 100081, China.
| | - Ming Chen
- Institute of Crop Science, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing 100081, China.
| | - Jin-Dong Fu
- Institute of Crop Science, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing 100081, China.
| | - You-Zhi Ma
- Institute of Crop Science, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing 100081, China.
| | - Hui Zhang
- Institute of Crop Science, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing 100081, China.
| | - Zhao-Shi Xu
- Institute of Crop Science, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing 100081, China.
| |
Collapse
|
3
|
Sun D, Ji X, Jia Y, Huo D, Si S, Zeng L, Zhang Y, Niu L. LreEF1A4, a Translation Elongation Factor from Lilium regale, Is Pivotal for Cucumber Mosaic Virus and Tobacco Rattle Virus Infections and Tolerance to Salt and Drought. Int J Mol Sci 2020; 21:E2083. [PMID: 32197393 PMCID: PMC7139328 DOI: 10.3390/ijms21062083] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 03/14/2020] [Accepted: 03/16/2020] [Indexed: 11/17/2022] Open
Abstract
Eukaryotic translation elongation factors are implicated in protein synthesis across different living organisms, but their biological functions in the pathogenesis of cucumber mosaic virus (CMV) and tobacco rattle virus (TRV) infections are poorly understood. Here, we isolated and characterized a cDNA clone, LreEF1A4, encoding the alpha subunit of elongation factor 1, from a CMV-elicited suppression subtractive hybridization library of Lilium regale. The infection tests using CMV remarkably increased transcript abundance of LreEF1A4; however, it also led to inconsistent expression profiles of three other LreEF1A homologs (LreEF1A1-3). Protein modelling analysis revealed that the amino acid substitutions among four LreEF1As may not affect their enzymatic functions. LreEF1A4 was ectopically overexpressed in petunia (Petunia hybrida), and transgenic plants exhibited delayed leaf and flower senescence, concomitant with increased transcription of photosynthesis-related genes and reduced expression of senescence-associated genes, respectively. A compromised resistance to CMV and TRV infections was found in transgenic petunia plants overexpressing LreEF1A4, whereas its overexpression resulted in an enhanced tolerance to salt and drought stresses. Taken together, our data demonstrate that LreEF1A4 functions as a positive regulator in viral multiplication and plant adaption to high salinity and dehydration.
Collapse
Affiliation(s)
- Daoyang Sun
- College of Landscape Architecture and Arts, Northwest A&F University, Yangling 712100, China
| | - Xiaotong Ji
- College of Landscape Architecture and Arts, Northwest A&F University, Yangling 712100, China
| | - Yong Jia
- State Agricultural Biotechnology Centre, School of Veterinary and Life Sciences, Murdoch University, Perth 6150, Australia
| | - Dan Huo
- College of Landscape Architecture and Arts, Northwest A&F University, Yangling 712100, China
| | - Shiying Si
- College of Landscape Architecture and Arts, Northwest A&F University, Yangling 712100, China
| | - Lingling Zeng
- College of Landscape Architecture and Arts, Northwest A&F University, Yangling 712100, China
| | - Yanlong Zhang
- College of Landscape Architecture and Arts, Northwest A&F University, Yangling 712100, China
| | - Lixin Niu
- College of Landscape Architecture and Arts, Northwest A&F University, Yangling 712100, China
| |
Collapse
|
4
|
Meng XL, Qi XH, Han ZY, Guo YB, Wang YN, Hu TL, Wang LM, Cao KQ, Wang ST. Latent Infection of Valsa mali in the Seeds, Seedlings and Twigs of Crabapple and Apple Trees is a Potential Inoculum Source of Valsa Canker. Sci Rep 2019; 9:7738. [PMID: 31123304 PMCID: PMC6533284 DOI: 10.1038/s41598-019-44228-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 05/13/2019] [Indexed: 11/20/2022] Open
Abstract
A real-time quantitative PCR assay using a species-specific primer pair was developed to rapidly and accurately quantify Valsa mali, the causative pathogen of apple Valsa canker (AVC), in crabapple seeds, crabapple seedlings, apple twigs and apple seeds. Surveys were conducted in different regions, and crabapple or apple seeds were collected for V. mali detection by qPCR assay. Our results showed that 12.87% to 49.01% of crabapple seeds collected from different regions were positive for V. mali. The exopleura and endopleura were the two major areas of V. mali infection in crabapple seeds. The presence of V. mali infection in crabapple seeds was also confirmed by a high-throughput sequencing approach. With the growth of crabapple seedlings, the concentration of V. mali gDNA in crabapple seedlings gradually increased until eight or more leaf blades emerged. One-year-old twigs from an apple scion nursery were infected with V. mali, and only apple seeds from infected apple trees showing evident Valsa canker symptoms carried V. mali. In conclusion, this study reports that crabapple seeds and apple seeds carried V. mali as latent inoculum sources. V. mali infected not only apple tissues but also crabapple seedlings, which are the rootstocks of apple trees. This study indicated that the inoculum sources for AVC vary. Application of a novel qPCR assay can potentially improve the accuracy of early diagnosis, and is helpful to reveal the epidemic regularity of AVC.
Collapse
Affiliation(s)
- Xiang-Long Meng
- College of Plant Protection, Hebei Agricultural University, Baoding, 071001, P.R. China
| | - Xing-Hua Qi
- College of Plant Protection, Hebei Agricultural University, Baoding, 071001, P.R. China
| | - Ze-Yuan Han
- College of Plant Protection, Hebei Agricultural University, Baoding, 071001, P.R. China
| | - Yong-Bin Guo
- College of Plant Protection, Hebei Agricultural University, Baoding, 071001, P.R. China
| | - Ya-Nan Wang
- College of Plant Protection, Hebei Agricultural University, Baoding, 071001, P.R. China
| | - Tong-le Hu
- College of Plant Protection, Hebei Agricultural University, Baoding, 071001, P.R. China
| | - Li-Ming Wang
- College of Plant Protection, Hebei Agricultural University, Baoding, 071001, P.R. China
| | - Ke-Qiang Cao
- College of Plant Protection, Hebei Agricultural University, Baoding, 071001, P.R. China.
| | - Shu-Tong Wang
- College of Plant Protection, Hebei Agricultural University, Baoding, 071001, P.R. China.
| |
Collapse
|
5
|
Qi H, Ning L, Yu Z, Dou G, Li L. Proteomic Identification of eEF1A1 as a Molecular Target of Curcumol for Suppressing Metastasis of MDA-MB-231 Cells. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2017; 65:3074-3082. [PMID: 28345336 DOI: 10.1021/acs.jafc.7b00573] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Curcumol, a major volatile component in Rhizoma Curcumae, exhibits a potent antimetastatic effect on breast cancer cells. However, its molecular mechanism remains poorly understood. In this study, we employed two-dimensional gel electrophoresis-based proteomics to investigate the cellular targets of curcumol in MDA-MB-231 cells and identified 10 differentially expressed proteins. Moreover, Gene Ontology analysis revealed that these proteins are mainly involved in nine types of cellular components, seven different biological processes, and nine kinds of molecular functions, and 35 pathways (p < 0.05) were enriched by KEGG pathway analysis. Specially, eEF1A1, a well-characterized actin binding protein, draws our attention. Curcumol decreased eEF1A1 expression at both mRNA and protein levels. EEF1A1 expression was shown to be correlated with the invasiveness of cancer cells. Importantly, overexpression of eEF1A1 significantly reversed the inhibition of curcumol regarding the invasion and adhesion of MDA-MB-231 cells (p < 0.05). Together, our data suggest that eEF1A1 may be a potential molecular target underlying the antimetastatic effect of curcumol.
Collapse
Affiliation(s)
- Hongyi Qi
- College of Pharmaceutical Sciences, Southwest University , Chongqing 400716, P.R. China
| | - Ling Ning
- College of Pharmaceutical Sciences, Southwest University , Chongqing 400716, P.R. China
| | - Zanyang Yu
- College of Pharmaceutical Sciences, Southwest University , Chongqing 400716, P.R. China
| | - Guojun Dou
- College of Pharmaceutical Sciences, Southwest University , Chongqing 400716, P.R. China
| | - Li Li
- College of Pharmaceutical Sciences, Southwest University , Chongqing 400716, P.R. China
| |
Collapse
|
6
|
Zhang H, Wei Q, Li C, Jiang C, Zhang H. Comparative Proteomic Analysis Provides Insights into the Regulation of Flower Bud Differentiation in Crocus SativusL. J Food Biochem 2016. [DOI: 10.1111/jfbc.12254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Hengfeng Zhang
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Longpan Road, Xuanwu District, Nanjing 210037, People's Republic of China
- College of Forestry, Nanjing Forestry Universtiy, Longpan Road, Xuanwu District, Nanjing 210037, People's Republic of China
- Department of Landscape and Horticulture, Jiangsu Agri-Animal Husbandry Vocational College, Fenghuang Road, Hailing District, Taizhou 225300, People's Republic of China
| | - Qingcui Wei
- Department of Landscape and Horticulture, Jiangsu Agri-Animal Husbandry Vocational College, Fenghuang Road, Hailing District, Taizhou 225300, People's Republic of China
| | - Chengzhong Li
- Department of Landscape and Horticulture, Jiangsu Agri-Animal Husbandry Vocational College, Fenghuang Road, Hailing District, Taizhou 225300, People's Republic of China
| | - Chunmao Jiang
- Department of Landscape and Horticulture, Jiangsu Agri-Animal Husbandry Vocational College, Fenghuang Road, Hailing District, Taizhou 225300, People's Republic of China
| | - Huanchao Zhang
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Longpan Road, Xuanwu District, Nanjing 210037, People's Republic of China
- College of Forestry, Nanjing Forestry Universtiy, Longpan Road, Xuanwu District, Nanjing 210037, People's Republic of China
| |
Collapse
|
7
|
Saraiva KDDC, Oliveira AER, Dos Santos CP, Lima KTL, de Sousa JM, Fernandes de Melo D, Costa JH. Phylogenetic analysis and differential expression of EF1α genes in soybean during development, stress and phytohormone treatments. Mol Genet Genomics 2016; 291:1505-22. [PMID: 26984342 DOI: 10.1007/s00438-016-1198-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 03/05/2016] [Indexed: 11/26/2022]
Abstract
The EF1α is a multifunctional protein with additional unrelated activities to its primary function in translation. This protein is encoded by a multigene family and few studies are still available in plants. Expression of six EF1α genes in Glycine max was performed using RT-qPCR and RNA-seq data to advance in the function of each gene during plant development, stress conditions and phytohormone treatments. A phylogenetic classification in Phaseoleae tribe was used to identify the G. max EF1α genes (EF1α 1a1, 1a2, 1b, 2a, 2b and 3). Three EF1α types (1-3) were found in Phaseoleae revealing duplications in G. max types 1 and 2. EF1α genes were expressed in all studied tissues, however, specific amount of each transcript was detected. In plant development, all EF1α transcripts were generally more expressed in younger tissues, however, in unifoliolate leaves and cotyledons a higher expression occurred in older tissues. Five EF1α genes (except 2a) were up-regulated under stress in a response tissue/stress/cultivar-dependent. EF1α 3 was the most stress-induced gene linked to cultivar stress tolerance mainly in aerial tissues. Auxin, salicylate and ethylene induced differentially the EF1α expression. Overall, this study provides a consistent EF1α classification in Phaseoleae tribe to better understand their functional evolution. The RT-qPCR and RNA-seq EF1α expression profiles were consistent, both exhibiting expression diversification of each gene (spatio-temporal, stress and phytohormone stimuli). Our results point out the EF1α genes, especially EF1α 3, as candidate for developing a useful tool for future G. max breeding.
Collapse
Affiliation(s)
- Kátia Daniella da Cruz Saraiva
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Campus do Pici, Cx., 6033, Fortaleza, Fortaleza, CE, 60451-970, Brazil
| | - Antonio Edson Rocha Oliveira
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Campus do Pici, Cx., 6033, Fortaleza, Fortaleza, CE, 60451-970, Brazil
| | - Clesivan Pereira Dos Santos
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Campus do Pici, Cx., 6033, Fortaleza, Fortaleza, CE, 60451-970, Brazil
| | - Karine Thiers Leitão Lima
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Campus do Pici, Cx., 6033, Fortaleza, Fortaleza, CE, 60451-970, Brazil
| | - Janaina Martins de Sousa
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Campus do Pici, Cx., 6033, Fortaleza, Fortaleza, CE, 60451-970, Brazil
| | - Dirce Fernandes de Melo
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Campus do Pici, Cx., 6033, Fortaleza, Fortaleza, CE, 60451-970, Brazil
| | - José Hélio Costa
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Campus do Pici, Cx., 6033, Fortaleza, Fortaleza, CE, 60451-970, Brazil.
| |
Collapse
|
8
|
Ermert AL, Mailliet K, Hughes J. Holophytochrome-Interacting Proteins in Physcomitrella: Putative Actors in Phytochrome Cytoplasmic Signaling. FRONTIERS IN PLANT SCIENCE 2016; 7:613. [PMID: 27242820 PMCID: PMC4867686 DOI: 10.3389/fpls.2016.00613] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2016] [Accepted: 04/21/2016] [Indexed: 05/26/2023]
Abstract
Phytochromes are the principle photoreceptors in light-regulated plant development, primarily acting via translocation of the light-activated photoreceptor into the nucleus and subsequent gene regulation. However, several independent lines of evidence indicate unambiguously that an additional cytoplasmic signaling mechanism must exist. Directional responses in filament tip cells of the moss Physcomitrella patens are steered by phy4 which has been shown to interact physically with the blue light receptor phototropin at the plasma membrane. This complex might perceive and transduce vectorial information leading to cytoskeleton reorganization and finally a directional growth response. We developed yeast two-hybrid procedures using photochemically functional, full-length phy4 as bait in Physcomitrella cDNA library screens and growth assays under different light conditions, revealing Pfr-dependent interactions possibly associated with phytochrome cytoplasmic signaling. Candidate proteins were then expressed in planta with fluorescent protein tags to determine their intracellular localization in darkness and red light. Of 14 candidates, 12 were confirmed to interact with phy4 in planta using bimolecular fluorescence complementation. We also used database information to study their expression patterns relative to those of phy4. We discuss the likely functional characteristics of these holophytochrome-interacting proteins (HIP's) and their possible roles in signaling.
Collapse
|
9
|
Kumagai F, Hasezawa S, Takahashi Y, Nagata T. The Involvement of Protein Synthesis Elongation Factor 1α in the Organization of Microtubules on the Perinuclear Region during the Cell Cycle Transition from M Phase to G1Phase in Tobacco BY-2 Cells. ACTA ACUST UNITED AC 2014. [DOI: 10.1111/j.1438-8677.1995.tb00523.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
10
|
Suhandono S, Apriyanto A, Ihsani N. Isolation and characterization of three cassava elongation factor 1 alpha (MeEF1A) promoters. PLoS One 2014; 9:e84692. [PMID: 24404183 PMCID: PMC3880305 DOI: 10.1371/journal.pone.0084692] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2013] [Accepted: 11/25/2013] [Indexed: 11/19/2022] Open
Abstract
In plant genetic engineering, the identification of gene promoters leading to particular expression patterns is crucial for the development of new genetically modified plant generations. This research was conducted in order to isolate and characterize several new promoters from cassava (Manihot esculenta Crantz) elongation factor 1 alpha (EF1A) gene family.Three promoters MeEF1A3, MeEF1A5 and MeEF1A6 were successfully isolated [corrected]. Sequence analyses showed that all of the promoters contain three conserved putative cis-acting elements which are located upstream of the transcription start site. These elements are included a TEF1, a TELO and TATA boxes. In addition, all of the promoters also have the 5'UTR intron but with a different lengths. These promoters were constructed translationally with gusA reporter gene (promoter::gusA fusion) in pBI-121 binary vector to build a new binary vector using Overlap Extension PCR Cloning (OEPC) technique. Transient expression assay that was done by using agroinfiltration method was used to show functionality of these promoters. Qualitative and quantitative analysis from GUS assay showed that these promoters were functional and conferred a specific activity in tobacco seedlings (Nicotiana tabacum), tomato fruits (Solanum lycopersicum) and banana fruits (Musa acuminata). We hypothesized that MeEF1A6 could be categorized as a constitutive promoter because it was able to drive the gene expression in all transformed tissue described in here and also comparable to CaMV35S. On the other hand, MeEF1A3 drove specific expression in the aerial parts of seedlings such as hypocotyl and cotyledon thus MeEF1A5 drove specific expression in fruit tissue. The results obtained from transient analysis showed that these promoters had a distinct activity although they came from same gene family. The DNA sequences identified here are new promoters potentially use for genetic engineering in cassava or other plants.
Collapse
Affiliation(s)
- Sony Suhandono
- School of Life Sciences and Technology, Institut Teknologi Bandung, Bandung, Jawa Barat, Indonesia
| | - Ardha Apriyanto
- School of Life Sciences and Technology, Institut Teknologi Bandung, Bandung, Jawa Barat, Indonesia
| | - Nisa Ihsani
- School of Life Sciences and Technology, Institut Teknologi Bandung, Bandung, Jawa Barat, Indonesia
| |
Collapse
|
11
|
Im YJ, Brglez I, Dieck C, Perera IY, Boss WF. Phosphatidylinositol 4-kinase and phosphatidylinositol 4-phosphate 5-kinase assays. Methods Mol Biol 2013; 1009:163-74. [PMID: 23681532 DOI: 10.1007/978-1-62703-401-2_15] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2023]
Abstract
Inositol lipid kinases are perhaps the easiest and most straightforward enzymes in the phosphoinositide pathway to analyze. In addition to monitoring lipid kinase-specific activity, lipid kinase assays can be used to quantify the inositol lipids present in isolated membranes (Jones et al., Methods Mol Biol 462:75-88, 2009). The lipid kinase assays are based on the fact that the more negatively charged phosphorylated lipid products are readily separated from their lipid substrates by thin layer chromatography. We have summarized our current protocols and identified important considerations for working with inositol lipids including different methods for substrate delivery when using recombinant proteins.
Collapse
Affiliation(s)
- Yang Ju Im
- Department of Plant Biology, North Carolina State University, Raleigh, NC, USA
| | | | | | | | | |
Collapse
|
12
|
Matsubayashi M, Teramoto-Kimata I, Uni S, Lillehoj HS, Matsuda H, Furuya M, Tani H, Sasai K. Elongation factor-1α is a novel protein associated with host cell invasion and a potential protective antigen of Cryptosporidium parvum. J Biol Chem 2013; 288:34111-34120. [PMID: 24085304 DOI: 10.1074/jbc.m113.515544] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The phylum Apicomplexa comprises obligate intracellular parasites that infect vertebrates. All invasive forms of Apicomplexa possess an apical complex, a unique assembly of organelles localized to the anterior end of the cell and involved in host cell invasion. Previously, we generated a chicken monoclonal antibody (mAb), 6D-12-G10, with specificity for an antigen located in the apical cytoskeleton of Eimeria acervulina sporozoites. This antigen was highly conserved among Apicomplexan parasites, including other Eimeria spp., Toxoplasma, Neospora, and Cryptosporidium. In the present study, we identified the apical cytoskeletal antigen of Cryptosporidium parvum (C. parvum) and further characterized this antigen in C. parvum to assess its potential as a target molecule against cryptosporidiosis. Indirect immunofluorescence demonstrated that the reactivity of 6D-12-G10 with C. parvum sporozoites was similar to those of anti-β- and anti-γ-tubulins antibodies. Immunoelectron microscopy with the 6D-12-G10 mAb detected the antigen both on the sporozoite surface and underneath the inner membrane at the apical region of zoites. The 6D-12-G10 mAb significantly inhibited in vitro host cell invasion by C. parvum. MALDI-TOF/MS and LC-MS/MS analysis of tryptic peptides revealed that the mAb 6D-12-G10 target antigen was elongation factor-1α (EF-1α). These results indicate that C. parvum EF-1α plays an essential role in mediating host cell entry by the parasite and, as such, could be a candidate vaccine antigen against cryptosporidiosis.
Collapse
Affiliation(s)
- Makoto Matsubayashi
- Department of Food and Nutrition, Osaka Yuhigaoka Gakuen Junior College, Tennoji-ku, Osaka 543-0073, Japan; Bacterial and Parasitic Disease Research Division, National Institute of Animal Health, National Agricultural and Food Research Organization, Tsukuba, Ibaraki 305-0856, Japan
| | - Isao Teramoto-Kimata
- Department of Parasitology, Graduate School of Medicine, Osaka City University, Abeno-ku, Osaka 545-8585, Japan
| | - Shigehiko Uni
- Department of Parasitology, Graduate School of Medicine, Osaka City University, Abeno-ku, Osaka 545-8585, Japan; Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Hyun S Lillehoj
- United States Department of Agriculture, Animal Biosciences and Biotechnology Laboratory, Beltsville Agricultural Research Center, Beltsville, Maryland 20705
| | - Haruo Matsuda
- Laboratory of Immunobiology, Department of Molecular and Applied Biosciences, Graduate School of Biosphere Sciences, Hiroshima University, Kagamiyama, Higashi-Hiroshima 739-8528, Japan
| | - Masaru Furuya
- Department of Veterinary Internal Medicine, Division of Veterinary Science, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Izumisano, Osaka 598-8531, Japan
| | - Hiroyuki Tani
- Department of Veterinary Internal Medicine, Division of Veterinary Science, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Izumisano, Osaka 598-8531, Japan
| | - Kazumi Sasai
- Department of Veterinary Internal Medicine, Division of Veterinary Science, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Izumisano, Osaka 598-8531, Japan.
| |
Collapse
|
13
|
Abstract
beta-Actin mRNA is localized near the leading edge in several cell types where actin polymerization is actively promoting forward protrusion. The localization of the beta-actin mRNA near the leading edge is facilitated by a short sequence in the 3'UTR (untranslated region), the 'zipcode'. Localization of the mRNA at this region is important physiologically. Treatment of chicken embryo fibroblasts with antisense oligonucleotides complementary to the localization sequence (zipcode) in the 3'UTR leads to delocalization of beta-actin mRNA, alteration of cell phenotype and a decrease in cell motility. The dynamic image analysis system (DIAS) used to quantify movement of cells in the presence of sense and antisense oligonucleotides to the zipcode showed that net pathlength and average speed of antisense-treated cells were significantly lower than in sense-treated cells. This suggests that a decrease in persistence of direction of movement and not in velocity results from treatment of cells with zipcode-directed antisense oligonucleotides. We postulate that delocalization of beta-actin mRNA results in delocalization of nucleation sites and beta-actin protein from the leading edge followed by loss of cell polarity and directional movement. Hence the physiological consequences of beta-actin mRNA delocalization affect the stability of the cell phenotype.
Collapse
Affiliation(s)
- John Condeelis
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | | |
Collapse
|
14
|
Abstract
"All things flow and change…even in the stillest matter there is unseen flux and movement." Attributed to Heraclitus (530-470 BC), from The Story of Philosophy by Will Durant. Heraclitus, a Greek philosopher, was thinking on a much larger scale than molecular signaling; however, his visionary comments are an important reminder for those studying signaling today. Even in unstimulated cells, signaling pathways are in constant metabolic flux and provide basal signals that travel throughout the organism. In addition, negatively charged phospholipids, such as the polyphosphorylated inositol phospholipids, provide a circuit board of on/off switches for attracting or repelling proteins that define the membranes of the cell. This template of charged phospholipids is sensitive to discrete changes and metabolic fluxes-e.g., in pH and cations-which contribute to the oscillating signals in the cell. The inherent complexities of a constantly fluctuating system make understanding how plants integrate and process signals challenging. In this review we discuss one aspect of lipid signaling: the inositol family of negatively charged phospholipids and their functions as molecular sensors and regulators of metabolic flux in plants.
Collapse
Affiliation(s)
- Wendy F Boss
- Department of Plant Biology, North Carolina State University, Raleigh, NC 27695-7649, USA.
| | | |
Collapse
|
15
|
Analysis of interaction partners for eukaryotic translation elongation factor 1A M-domain by functional proteomics. Biochimie 2011; 93:1738-46. [DOI: 10.1016/j.biochi.2011.06.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Accepted: 06/07/2011] [Indexed: 12/18/2022]
|
16
|
Pinke DE, Lee JM. The lipid kinase PI4KIIIβ and the eEF1A2 oncogene co-operate to disrupt three-dimensional in vitro acinar morphogenesis. Exp Cell Res 2011; 317:2503-11. [PMID: 21851817 DOI: 10.1016/j.yexcr.2011.08.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Revised: 07/29/2011] [Accepted: 08/01/2011] [Indexed: 11/25/2022]
Abstract
The study of in vitro morphogenesis is fundamental to understanding neoplasia since the dysregulation of morphogenic pathways that create multi-cellular organisms is a common hallmark of oncogenesis. The in vitro culture of human breast epithelial cells on reconstituted basement membranes recapitulate some features of in vivo breast development, including the formation of a three-dimensional structure termed an acinus. Importantly, the capacity to disrupt in vitro acinar morphogenesis is a common property of human breast oncogenes. In this report, we find that phosphatidylinositol 4-kinase IIIβ (PI4KIIIβ), a lipid kinase that phosphorylates phosphatidylinositol (PI) to PI(4)P, disrupts in vitro mammary acinar formation. The PI4KIIIβ protein localizes to the basal surface of acini created by human MCF10A cells and ectopic expression of PI4KIIIβ induces multi-acinar devlopment. Furthermore, expression of an oncogenic PI4KIIIβ activator, eEF1A2 (eukaryotic elongation factor 1 alpha 2), phenocopies the PI4KIIIβ multi-acinar phenotype. Ectopic expression of PI4KIIIβ or eEF1A2 alters the localization of PI(4)P and PI(4,5)P(2) within acini, indicating the importance of these lipids in acinar development. Our work shows that PI4KIIIβ, eEF1A2 and PI(4)P likely play an important role in mammary neoplasia and acinar development.
Collapse
Affiliation(s)
- Dixie E Pinke
- Department of Biochemistry, University of Ottawa, 451 Smyth Road, Ottawa, Ontario, Canada K1H 8M5
| | | |
Collapse
|
17
|
Zhong D, Zhang J, Yang S, Soh UJK, Buschdorf JP, Zhou YT, Yang D, Low BC. The SAM domain of the RhoGAP DLC1 binds EF1A1 to regulate cell migration. J Cell Sci 2009; 122:414-24. [PMID: 19158340 DOI: 10.1242/jcs.027482] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Deleted in liver cancer 1 (DLC1) is a multi-modular Rho-GTPase-activating protein (RhoGAP) and a tumor suppressor. Besides its RhoGAP domain, functions of other domains in DLC1 remain largely unknown. By protein precipitation and mass spectrometry, we identified eukaryotic elongation factor 1A1 (EF1A1) as a novel partner for the sterile alpha motif (SAM) domain of DLC1 but not the SAM domain of DLC2. The solution structure of DLC1 SAM revealed a new monomeric fold with four parallel helices, similar to that of DLC2 SAM but distinct from other SAM domains. Mutating F38, L39 and F40 within a hydrophobic patch retained its overall structure but abolished its interaction with EF1A1 with F38 and L39 forming an indispensable interacting motif. DLC1 SAM did not localize to and was not required for DLC1 to suppress the turnover of focal adhesions. Instead, DLC1 SAM facilitated EF1A1 distribution to the membrane periphery and ruffles upon growth factor stimulation. Compared with wild-type DLC1, the non-interactive DLC1 mutant is less potent in suppressing cell migration, whereas overexpression of the DLC1 SAM domain alone, but not the non-interactive mutant SAM or DLC2 SAM, greatly enhanced cell migration. This finding reveals a novel contribution of the SAM-EF1A1 interaction as a potentially important GAP-independent modulation of cell migration by DLC1.
Collapse
Affiliation(s)
- Dandan Zhong
- Cell Signaling and Developmental Biology Laboratory, Department of Biological Sciences, National University of Singapore, Singapore, Republic of Singapore
| | | | | | | | | | | | | | | |
Collapse
|
18
|
Murray LM, Thomson D, Conklin A, Wishart TM, Gillingwater TH. Loss of translation elongation factor (eEF1A2) expression in vivo differentiates between Wallerian degeneration and dying-back neuronal pathology. J Anat 2009; 213:633-45. [PMID: 19094180 DOI: 10.1111/j.1469-7580.2008.01007.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Wallerian degeneration and dying-back pathology are two well-known cellular pathways capable of regulating the breakdown and loss of axonal and synaptic compartments of neurons in vivo. However, the underlying mechanisms and molecular triggers of these pathways remain elusive. Here, we show that loss of translation elongation factor eEF1A2 expression in lower motor neurons and skeletal muscle fibres in homozygous Wasted mice triggered a dying-back neuropathy. Synaptic loss at the neuromuscular junction occurred in advance of axonal pathology and by a mechanism morphologically distinct from Wallerian degeneration. Dying-back pathology in Wasted mice was accompanied by reduced expression levels of the zinc finger protein ZPR1, as found in other dying-back neuropathies such as spinal muscular atrophy. Surprisingly, experimental nerve lesion revealed that Wallerian degeneration was significantly delayed in homozygous Wasted mice; morphological assessment revealed that approximately 80% of neuromuscular junctions in deep lumbrical muscles at 24 h and approximately 50% at 48 h had retained motor nerve terminals following tibial nerve lesion. This was in contrast to wild-type and heterozygous Wasted mice where < 5% of neuromuscular junctions had retained motor nerve terminals at 24 h post-lesion. These data show that eEF1A2 expression is required to prevent the initiation of dying-back pathology at the neuromuscular junction in vivo. In contrast, loss of eEF1A2 expression significantly inhibited the initiation and progression of Wallerian degeneration in vivo. We conclude that loss of eEF1A2 expression distinguishes mechanisms underlying dying-back pathology from those responsible for Wallerian degeneration in vivo and suggest that eEF1A2-dependent cascades may provide novel molecular targets to manipulate neurodegenerative pathways in lower motor neurons.
Collapse
Affiliation(s)
- Lyndsay M Murray
- Centre for Integrative Physiology, College of Medicine, and Veterinary Medicine, University of Edinburgh, Edinburgh, EH8 9XD, UK
| | | | | | | | | |
Collapse
|
19
|
Cao H, Zhu Q, Huang J, Li B, Zhang S, Yao W, Zhang Y. Regulation and functional role of eEF1A2 in pancreatic carcinoma. Biochem Biophys Res Commun 2009; 380:11-6. [PMID: 19138673 DOI: 10.1016/j.bbrc.2008.12.171] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2008] [Accepted: 12/30/2008] [Indexed: 02/07/2023]
Abstract
Pancreatic cancer typically has an unfavourable prognosis due to late diagnosis and a lack of therapeutic options. Thus, it is important to better understand its pathological mechanism and to develop more effective treatments for the disease. Human chromosome 20q13 has long been suspected to harbour oncogenes involved in pancreatic cancer and other tumours. In this study, we found that eEF1A2, a gene located in 20q13, was significantly upregulated in pancreatic cancer. Little or no expression of eEF1A2 was detected in normal human pancreatic and chronic pancreatitis tissues, whereas increased eEF1A2 expression occurred in 83% of the pancreatic cancers we studied. Furthermore, using in vitro and in vivo model systems, we found that overexpression of eEF1A2 promoted cell growth, survival, and invasion in pancreatic cancer. Our data thus suggest that eEF1A2 might play an important role in pancreatic carcinogenesis, possibly by acting as a tumour oncogene.
Collapse
Affiliation(s)
- Haixia Cao
- Department of Gastroenterology, Rui Jin Hospital, Shanghai Jiaotong University School of Medicine, No. 197 Rui Jin Er Road, Shanghai 200025, China
| | | | | | | | | | | | | |
Collapse
|
20
|
Ransom-Hodgkins WD. The application of expression analysis in elucidating the eukaryotic elongation factor one alpha gene family in Arabidopsis thaliana. Mol Genet Genomics 2009; 281:391-405. [PMID: 19132394 DOI: 10.1007/s00438-008-0418-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2008] [Accepted: 12/22/2008] [Indexed: 10/21/2022]
Abstract
Eukaryotic elongation factor one alpha (eEF1A) encoding genes are part of the large GTP binding protein family. The eEF1A family is important for protein synthesis and actin filament and bundle formation. In this study, the expression of four eEF1A genes in Arabidopsis thaliana is reported. Microarray analyses of the gene family showed high expression levels in germinating seeds, embryos, and shoot and root meristems. Quantitative real time RT-PCR was used to determine individual eEF1A gene expression. Unlike animals, in Arabidopsis tissues all four eEF1A genes were expressed in all tissues sampled. However, the abundance of each transcript varied spatially. Knocking out expression of one eEF1A gene produced seedlings with stunted roots and a subsequent change in expression of the other three eEF1A genes. The varying abundance of each gene in different tissues may indicate different concentration requirements for each message product. These results will be very useful for elucidating the role of each gene in growth, development, and stress responses of the plant.
Collapse
Affiliation(s)
- Wendy Danielle Ransom-Hodgkins
- Department of Biological Sciences, Western Michigan University, 1903 West Michigan Avenue, Kalamazoo, MI 49008-5410, USA.
| |
Collapse
|
21
|
Vermeer JEM, Thole JM, Goedhart J, Nielsen E, Munnik T, Gadella TWJ. Imaging phosphatidylinositol 4-phosphate dynamics in living plant cells. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2009; 57:356-72. [PMID: 18785997 DOI: 10.1111/j.1365-313x.2008.03679.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Polyphosphoinositides represent a minor group of phospholipids, accounting for less than 1% of the total. Despite their low abundance, these molecules have been implicated in various signalling and membrane trafficking events. Phosphatidylinositol 4-phosphate (PtdIns4P) is the most abundant polyphosphoinositide. (32)Pi-labelling studies have shown that the turnover of PtdIns4P is rapid, but little is known about where in the cell or plant this occurs. Here, we describe the use of a lipid biosensor that monitors PtdIns4P dynamics in living plant cells. The biosensor consists of a fusion between a fluorescent protein and a lipid-binding domain that specifically binds PtdIns4P, i.e. the pleckstrin homology domain of the human protein phosphatidylinositol-4-phosphate adaptor protein-1 (FAPP1). YFP-PH(FAPP1) was expressed in four plant systems: transiently in cowpea protoplasts, and stably in tobacco BY-2 cells, Medicago truncatula roots and Arabidopsis thaliana seedlings. All systems allowed YFP-PH(FAPP1) expression without detrimental effects. Two distinct fluorescence patterns were observed: labelling of motile punctate structures and the plasma membrane. Co-expression studies with organelle markers revealed strong co-labelling with the Golgi marker STtmd-CFP, but not with the endocytic/pre-vacuolar marker GFP-AtRABF2b. Co-expression with the Ptdins3P biosensor YFP-2 x FYVE revealed totally different localization patterns. During cell division, YFP-PH(FAPP1) showed strong labelling of the cell plate, but PtdIns3P was completely absent from the newly formed cell membrane. In root hairs of M. truncatula and A. thaliana, a clear PtdIns4P gradient was apparent in the plasma membrane, with the highest concentration in the tip. This only occurred in growing root hairs, indicating a role for PtdIns4P in tip growth.
Collapse
Affiliation(s)
- Joop E M Vermeer
- Department of Molecular Cytology, Centre for Advanced Microscopy, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | | | | | | | | | | |
Collapse
|
22
|
Leclercq TM, Moretti PAB, Vadas MA, Pitson SM. Eukaryotic elongation factor 1A interacts with sphingosine kinase and directly enhances its catalytic activity. J Biol Chem 2008; 283:9606-14. [PMID: 18263879 PMCID: PMC2442288 DOI: 10.1074/jbc.m708782200] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2007] [Revised: 01/23/2008] [Indexed: 01/07/2023] Open
Abstract
Sphingosine 1-phosphate (S1P) has many important roles in mammalian cells, including contributing to the control of cell survival and proliferation. S1P is generated by sphingosine kinases (SKs), of which two mammalian isoforms have been identified (SK1 and SK2). To gain a better understanding of SK regulation, we have used a yeast two-hybrid screen to identify SK1-interacting proteins and established elongation factor 1A (eEF1A) as one such protein that associates with both SK1 and SK2. We show the direct interaction of eEF1A with the SKs in vitro, whereas the physiological relevance of this association was demonstrated by co-immunoprecipitation of the endogenous proteins from cell lysates. Although the canonical role of eEF1A resides in protein synthesis, it has also been implicated in other roles, including regulating the activity of some signaling enzymes. Thus, we examined the potential role of eEF1A in regulation of the SKs and show that eEF1A is able to directly increase the activity of SK1 and SK2 approximately 3-fold in vitro. Substrate kinetics demonstrated that eEF1A increased the catalytic rate of both SKs, while having no observable effect on substrate affinities of these enzymes for either ATP or sphingosine. Overexpression of eEF1A in quiescent Chinese hamster ovary cells increased cellular SK activity, whereas a small interfering RNA-mediated decrease in eEF1A levels in MCF7 cells substantially reduced cellular SK activity and S1P levels, supporting the in vivo physiological relevance of this interaction. Thus, this study has established a novel mechanism of regulation of both SK1 and SK2 that is mediated by their interaction with eEF1A.
Collapse
Affiliation(s)
- Tamara M Leclercq
- Hanson Institute, Division of Human Immunology, Institute of Medical and Veterinary Science, Frome Road, Adelaide, South Australia 5000, Australia
| | | | | | | |
Collapse
|
23
|
Infante C, Asensio E, Cañavate JP, Manchado M. Molecular characterization and expression analysis of five different elongation factor 1 alpha genes in the flatfish Senegalese sole (Solea senegalensis Kaup): differential gene expression and thyroid hormones dependence during metamorphosis. BMC Mol Biol 2008; 9:19. [PMID: 18234081 PMCID: PMC2270864 DOI: 10.1186/1471-2199-9-19] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2007] [Accepted: 01/30/2008] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Eukaryotic elongation factor 1 alpha (eEF1A) is one of the four subunits composing eukaryotic translation elongation factor 1. It catalyzes the binding of aminoacyl-tRNA to the A-site of the ribosome in a GTP-dependent manner during protein synthesis, although it also seems to play a role in other non-translational processes. Currently, little information is still available about its expression profile and regulation during flatfish metamorphosis. With regard to this, Senegalese sole (Solea senegalensis) is a commercially important flatfish in which eEF1A gene remains to be characterized. RESULTS The development of large-scale genomics of Senegalese sole has facilitated the identification of five different eEF1A genes, referred to as SseEF1A1, SseEF1A2, SseEF1A3, SseEF1A4, and Sse42Sp50. Main characteristics and sequence identities with other fish and mammalian eEF1As are described. Phylogenetic and tissue expression analyses allowed for the identification of SseEF1A1 and SseEF1A2 as the Senegalese sole counterparts of mammalian eEF1A1 and eEF1A2, respectively, and of Sse42Sp50 as the ortholog of Xenopus laevis and teleost 42Sp50 gene. The other two elongation factors, SseEF1A3 and SseEF1A4, represent novel genes that are mainly expressed in gills and skin. The expression profile of the five genes was also studied during larval development, revealing different behaviours. To study the possible regulation of SseEF1A gene expressions by thyroid hormones (THs), larvae were exposed to the goitrogen thiourea (TU). TU-treated larvae exhibited lower SseEF1A4 mRNA levels than untreated controls at both 11 and 15 days after treatment, whereas transcripts of the other four genes remained relatively unchanged. Moreover, addition of exogenous T4 hormone to TU-treated larvae increased significantly the steady-state levels of SseEF1A4 with respect to untreated controls, demonstrating that its expression is up-regulated by THs. CONCLUSION We have identified five different eEF1A genes in the Senegalese sole, referred to as SseEF1A1, SseEF1A2, SseEF1A3, SseEF1A4, and Sse42Sp50. The five genes exhibit different expression patterns in tissues and during larval development. TU and T4 treatments demonstrate that SseEF1A4 is up-regulated by THs, suggesting a role in the translational regulation of the factors involved in the dramatic changes that occurs during Senegalese sole metamorphosis.
Collapse
Affiliation(s)
- Carlos Infante
- IFAPA Centro El Toruño, Junta de Andalucía, Camino Tiro de pichón s/n, 11500 El Puerto de Santa María, Cádiz, Spain.
| | | | | | | |
Collapse
|
24
|
Abstract
Synaptic vesicles are key organelles in neurotransmission. Vesicle integral or membrane-associated proteins mediate the various functions the organelle fulfills during its life cycle. These include organelle transport, interaction with the nerve terminal cytoskeleton, uptake and storage of low molecular weight constituents, and the regulated interaction with the pre-synaptic plasma membrane during exo- and endocytosis. Within the past two decades, converging work from several laboratories resulted in the molecular and functional characterization of the proteinaceous inventory of the synaptic vesicle compartment. However, up until recently and due to technical difficulties, it was impossible to screen the entire organelle thoroughly. Recent advances in membrane protein identification and mass spectrometry (MS) have dramatically promoted this field. A comparison of different techniques for elucidating the proteinaceous composition of synaptic vesicles revealed numerous overlaps but also remarkable differences in the protein constituents of the synaptic vesicle compartment, indicating that several protein separation techniques in combination with differing MS approaches are required to identify and characterize the synaptic vesicle proteome. This review highlights the power of various gel separation techniques and MS analyses for the characterization of the proteome of highly purified synaptic vesicles. Furthermore, the newly detected protein assignments to synaptic vesicles, especially those proteins which are new to the inventory of the synaptic vesicle proteome, are critically discussed.
Collapse
Affiliation(s)
- Jacqueline Burré
- Institute of Cell Biology and Neuroscience, Neurochemistry, JW Goethe University, Frankfurt, Germany.
| | | |
Collapse
|
25
|
Amiri A, Noei F, Jeganathan S, Kulkarni G, Pinke DE, Lee JM. eEF1A2 activates Akt and stimulates Akt-dependent actin remodeling, invasion and migration. Oncogene 2006; 26:3027-40. [PMID: 17130842 DOI: 10.1038/sj.onc.1210101] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
eEF1A2 (eukaryotic protein elongation factor 1 alpha 2) is a protein translation factor that is likely a human oncogene by virtue of its capacity to transform mammalian cells and its high expression in tumors of the ovary, breast and lung. Here, we show that expression of eEF1A2 is sufficient to stimulate the formation of filopodia in BT549 human breast cancer cells and non-transformed Rat2 cells. Filopodia formation in eEF1A2-expressing cells is dependent on the activity of phosphatidylinositol-3 kinase (PI3K), and the ROCK and Akt kinases. Furthermore, eEF1A2 expression is sufficient to activate Akt in a PI3K-dependent fashion and inactivation of eEF1A2 by short interfering RNA reduces Akt activity. Using breast cancer cell line BT 549, we show that eEF1A2 expression stimulates cell migration and invasion in a largely PI3K- and Akt-dependent manner. These results suggest that eEF1A2 regulates oncogenesis through Akt and PI3K-dependent cytoskeletal remodeling.
Collapse
Affiliation(s)
- A Amiri
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada
| | | | | | | | | | | |
Collapse
|
26
|
Jeganathan S, Lee JM. Binding of elongation factor eEF1A2 to phosphatidylinositol 4-kinase beta stimulates lipid kinase activity and phosphatidylinositol 4-phosphate generation. J Biol Chem 2006; 282:372-80. [PMID: 17088255 DOI: 10.1074/jbc.m602955200] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Eukaryotic protein translation elongation factor 1 alpha 2 (eEF1A2) is an oncogene that transforms mammalian cell lines and increases their tumorigenicity in nude mice. Increased expression of eEF1A2 occurs during the development of breast, ovarian, and lung cancer. Here, we report that eEF1A2 directly binds to and activates phosphatidylinositol 4-kinase III beta (PI4KIIIbeta), an enzyme that converts phosphatidylinositol to phosphatidylinositol 4-phosphate. Purified recombinant eEF1A2 increases PI4KIIIbeta lipid kinase activity in vitro, and expression of eEF1A2 in rat and human cells is sufficient to increase overall cellular phosphatidylinositol 4-kinase activity and intracellular phosphatidylinositol 4-phosphate abundance. siRNA-mediated reduction in eEF1A2 expression concomitantly reduces phosphatidylinositol 4-kinase activity. This identifies a physical and functional relationship between eEF1A2 and PI4KIIIbeta.
Collapse
Affiliation(s)
- Sujeeve Jeganathan
- Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | | |
Collapse
|
27
|
Kulkarni G, Turbin DA, Amiri A, Jeganathan S, Andrade-Navarro MA, Wu TD, Huntsman DG, Lee JM. Expression of protein elongation factor eEF1A2 predicts favorable outcome in breast cancer. Breast Cancer Res Treat 2006; 102:31-41. [PMID: 16897428 DOI: 10.1007/s10549-006-9315-8] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2006] [Accepted: 06/18/2006] [Indexed: 12/19/2022]
Abstract
Breast cancer is the most common malignancy among North American women. The identification of factors that predict outcome is key to individualized disease management and to our understanding of breast oncogenesis. We have analyzed mRNA expression of protein elongation factor eEF1A2 in two independent breast tumor populations of size n = 345 and n = 88, respectively. We find that eEF1A2 mRNA is expressed at a low level in normal breast epithelium but is detectably expressed in approximately 50-60% of primary human breast tumors. We have derived an eEF1A2-specific antibody and measured eEF1A2 protein expression in a sample of 438 primary breast tumors annotated with 20-year survival data. We find that high levels of eEF1A2 protein are detected in 60% of primary breast tumors independent of HER-2 protein expression, tumor size, lymph node status, and estrogen receptor (ER) expression. Importantly, we find that high eEF1A2 is a significant predictor of outcome. Women whose tumor has high eEF1A2 protein expression have an increased probability of 20-year survival compared to those women whose tumor does not express substantial eEF1A2. In addition, eEF1A2 protein expression predicts increased survival probability in those breast cancer patients whose tumor is HER-2 negative or who have lymph node involvement.
Collapse
Affiliation(s)
- Geeta Kulkarni
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, 451 Smyth Road, K1H 8M5 Ottawa, ON, Canada
| | | | | | | | | | | | | | | |
Collapse
|
28
|
Dowd PE, Coursol S, Skirpan AL, Kao TH, Gilroy S. Petunia phospholipase c1 is involved in pollen tube growth. THE PLANT CELL 2006; 18:1438-53. [PMID: 16648366 PMCID: PMC1475500 DOI: 10.1105/tpc.106.041582] [Citation(s) in RCA: 163] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2006] [Revised: 03/17/2006] [Accepted: 04/05/2006] [Indexed: 05/08/2023]
Abstract
Although pollen tube growth is essential for plant fertilization and reproductive success, the regulators of the actin-related growth machinery and the cytosolic Ca2+ gradient thought to determine how these cells elongate remain poorly defined. Phospholipases, their substrates, and their phospholipid turnover products have been proposed as such regulators; however, the relevant phospholipase(s) have not been characterized. Therefore, we cloned cDNA for a pollen-expressed phosphatidylinositol 4,5-bisphosphate (PtdInsP2)-cleaving phospholipase C (PLC) from Petunia inflata, named Pet PLC1. Expressing a catalytically inactive form of Pet PLC1 in pollen tubes caused expansion of the apical Ca2+ gradient, disruption of the organization of the actin cytoskeleton, and delocalization of growth at the tube tip. These phenotypes were suppressed by depolymerizing actin with low concentrations of latrunculin B, suggesting that a critical site of action of Pet PLC1 is in regulating actin structure at the growing tip. A green fluorescent protein (GFP) fusion to Pet PLC1 caused enrichment in regions of the apical plasma membrane not undergoing rapid expansion, whereas a GFP fusion to the PtdInsP2 binding domain of mammalian PLC delta1 caused enrichment in apical regions depleted in PLC. Thus, Pet PLC1 appears to be involved in the machinery that restricts growth to the very apex of the elongating pollen tube, likely through its regulatory action on PtdInsP2 distribution within the cell.
Collapse
Affiliation(s)
- Peter E Dowd
- Department of Biochemistry and Molecular Biology, Pensylvania State University, University Park, Pensylvania 16802, USA
| | | | | | | | | |
Collapse
|
29
|
Choi YH, Kim HK, Linthorst HJM, Hollander JG, Lefeber AWM, Erkelens C, Nuzillard JM, Verpoorte R. NMR metabolomics to revisit the tobacco mosaic virus infection in Nicotiana tabacum leaves. JOURNAL OF NATURAL PRODUCTS 2006; 69:742-8. [PMID: 16724833 DOI: 10.1021/np050535b] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Tobacco mosaic virus (TMV) infection of tobacco is a well-known and extensively studied model system for which a number of genes and proteins involved in the systemic acquired resistance (SAR) have been characterized. Little is known about the metabolic changes connected with the infection and SAR. Here we describe the use of NMR spectroscopy in combination with multivariate data analysis to study the metabolic changes. Particularly 2-D NMR methods, such as 2-D J-resolved spectra and their projected spectra, are shown to be powerful tools in the metabolomic studies. The macroscopic view of the metabolomes obtained by NMR spectroscopy of crude extracts enabled the identification of a series of totally different metabolites that seem connected with resistance, such as the clearly increased 5-caffeoylquinic acid, alpha-linolenic acid analogues, and sesqui- and diterpenoids in the infected plant parts.
Collapse
Affiliation(s)
- Young Hae Choi
- Division of Pharmacognosy, Section Metabolomics, Institute of Biology, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | | | | | | | | | | | | | | |
Collapse
|
30
|
Kanzawa N, Hoshino Y, Chiba M, Hoshino D, Kobayashi H, Kamasawa N, Kishi Y, Osumi M, Sameshima M, Tsuchiya T. Change in the actin cytoskeleton during seismonastic movement of Mimosa pudica. PLANT & CELL PHYSIOLOGY 2006; 47:531-9. [PMID: 16489209 DOI: 10.1093/pcp/pcj022] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
The seismonastic movement of Mimosa pudica is triggered by a sudden loss of turgor pressure. In the present study, we compared the cell cytoskeleton by immunofluorescence analysis before and after movement, and the effects of actin- and microtubule-targeted drugs were examined by injecting them into the cut pulvinus. We found that fragmentation of actin filaments and microtubules occurs during bending, although the actin cytoskeleton, but not the microtubules, was involved in regulation of the movement. Transmission electron microscopy revealed that actin cables became loose after the bending. We injected phosphatase inhibitors into the severed pulvinus to examine the effects of such inhibitors on the actin cytoskeleton. We found that changes in actin isoforms, fragmentation of actin filaments and the bending movement were all inhibited after injection of a tyrosine phosphatase inhibitor. We thus propose that the phosphorylation status of actin at tyrosine residues affects the dynamic reorganization of actin filaments and causes seismonastic movement.
Collapse
Affiliation(s)
- Nobuyuki Kanzawa
- Department of Chemistry, Faculty of Science and Technology, Sophia University, Tokyo, 102-8554 Japan.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Lopez-Valenzuela JA, Gibbon BC, Hughes PA, Dreher TW, Larkins BA. eEF1A isoforms change in abundance and actin-binding activity during maize endosperm development. PLANT PHYSIOLOGY 2003; 133:1285-95. [PMID: 14526107 PMCID: PMC281623 DOI: 10.1104/pp.103.027854] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2003] [Revised: 07/07/2003] [Accepted: 07/27/2003] [Indexed: 05/20/2023]
Abstract
Eukaryotic elongation factor 1A (eEF1A) appears to be a multifunctional protein because several biochemical activities have been described for this protein, in addition to its role in protein synthesis. In maize (Zea mays) endosperm, the synthesis of eEF1A is increased in o2 (opaque2) mutants, and its concentration is highly correlated with the protein-bound lysine content. To understand the basis of this relationship, we purified eEF1A isoforms from developing endosperm and investigated their accumulation and their functional and structural properties. Formation of three isoforms appears to be developmentally regulated and independent of the o2 mutation, although one isoform predominated in one high lysine o2 inbred. The purified proteins differ in their ability to bind F-actin in vitro, suggesting that they are functionally distinct. However, they share similar aminoacyl-tRNA-binding activities. Tandem mass spectrometry revealed that each isoform is composed of the four same gene products, which are modified posttranslationally by methylation and phosphorylation. The chemical differences that account for their different actin-binding activities could not be determined.
Collapse
|
32
|
Dallo SF, Kannan TR, Blaylock MW, Baseman JB. Elongation factor Tu and E1 beta subunit of pyruvate dehydrogenase complex act as fibronectin binding proteins in Mycoplasma pneumoniae. Mol Microbiol 2002; 46:1041-51. [PMID: 12421310 DOI: 10.1046/j.1365-2958.2002.03207.x] [Citation(s) in RCA: 236] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The interactions between pathogenic bacteria and extracellular matrix (ECM) components markedly influence the initiation and establishment of infection. We have identified two surface proteins of virulent Mycoplasma pneumoniae with molecular masses of 45 and 30 kDa that bind to the ECM constituent, fibronectin (Fn). These Fn-binding proteins (FnBPs) were purified to near homogeneity using Fn-coupled Sepharose 4B-affinity column chromatography, and amino acid sequence analysis of the 45 and the 30 kDa proteins identified them as elongation factor Tu (EF-Tu) and pyruvate dehydrogenase E1 beta subunit (PDH-B) respectively. The genes for EF-Tu and PDH-B were cloned, and the entire EF-Tu gene and NH2-terminus of PDH-B (NPDH (pyruvate dehydrogenase E1 beta subunit from amino acid 1-244)-B) gene were overexpressed in Escherichia coli. The recombinant proteins, rEF-Tu and rNPDH-B, were purified to homogeneity by His-tag affinity column chromatography and used to immunize rabbits. Purified rEF-Tu and rNPDH-B bound to Fn using a ligand immunoblot assay and ELISA. Immunogold electron microscopy with polyclonal antibodies reactive against rEF-Tu (antirEF-Tu) and rNPDH-B (antirNPDH-B) and whole cell radioimmunoprecipitation (WCRIP) revealed the surface location of these proteins. Adherence of viable M. pneumoniae to immobilized Fn was inhibited by antirEF-Tu and antirNPDH-B antisera in a dose-dependent and cumulative manner. These results demonstrate that M. pneumoniae EF-Tu and PDH-B, in addition to their major cytoplasmic biosynthetic and metabolic roles, can be surface translocated, which confers additional important biological functions.
Collapse
Affiliation(s)
- Shatha F Dallo
- Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, TX 78229, USA
| | | | | | | |
Collapse
|
33
|
Mueller-Roeber B, Pical C. Inositol phospholipid metabolism in Arabidopsis. Characterized and putative isoforms of inositol phospholipid kinase and phosphoinositide-specific phospholipase C. PLANT PHYSIOLOGY 2002; 130:22-46. [PMID: 12226484 PMCID: PMC166537 DOI: 10.1104/pp.004770] [Citation(s) in RCA: 291] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Phosphoinositides (PIs) constitute a minor fraction of total cellular lipids in all eukaryotic cells. They fulfill many important functions through interaction with a wide range of cellular proteins. Members of distinct inositol lipid kinase families catalyze the synthesis of these phospholipids from phosphatidylinositol. The hydrolysis of PIs involves phosphatases and isoforms of PI-specific phospholipase C. Although our knowledge of the roles played by plant PIs is clearly limited at present, there is no doubt that they are involved in many physiological processes during plant growth and development. In this review, we concentrate on inositol lipid-metabolizing enzymes from the model plant Arabidopsis for which biochemical characterization data are available, namely the inositol lipid kinases and PI-specific phospholipase Cs. The biochemical properties and structure of characterized and genome-predicted isoforms are presented and compared with those of the animal enzymes to show that the plant enzymes have some features clearly unique to this kingdom.
Collapse
Affiliation(s)
- Bernd Mueller-Roeber
- Universität Potsdam, Institut für Biochemie und Biologie, Abteilung Molekularbiologie, Karl-Liebknecht-Strasse 25, Haus 20, D-14476 Golm/Potsdam, Germany
| | | |
Collapse
|
34
|
Chang JS, Seok H, Kwon TK, Min DS, Ahn BH, Lee YH, Suh JW, Kim JW, Iwashita S, Omori A, Ichinose S, Numata O, Seo JK, Oh YS, Suh PG. Interaction of elongation factor-1alpha and pleckstrin homology domain of phospholipase C-gamma 1 with activating its activity. J Biol Chem 2002; 277:19697-702. [PMID: 11886851 DOI: 10.1074/jbc.m111206200] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The pleckstrin homology (PH) domain is a small motif for membrane targeting in the signaling molecules. Phospholipase C (PLC)-gamma1 has two putative PH domains, an NH(2)-terminal and a split PH domain. Here we report studies on the interaction of the PH domain of PLC-gamma1 with translational elongation factor (EF)-1alpha, which has been shown to be a phosphatidylinositol 4-kinase activator. By pull-down of cell extract with the glutathione S-transferase (GST) fusion proteins with various domains of PLC-gamma1 followed by peptide sequence analysis, we identified EF-1alpha as a binding partner of a split PH domain of PLC-gamma1. Analysis by site-directed mutagenesis of the PH domain revealed that the beta2-sheet of a split PH domain is critical for the interaction with EF-1alpha. Moreover, Dot-blot assay shows that a split PH domain specifically binds to phosphoinositides including phosphatidylinositol 4-phosphate and phosphatidylinositol 4, 5-bisphosphate (PIP(2)). So the PH domain of PLC-gamma1 binds to both EF-1alpha and PIP(2). The binding affinity of EF-1alpha to the GST.PH domain fusion protein increased in the presence of PIP(2), although PIP(2) does not bind to EF-1alpha directly. This suggests that EF-1alpha may control the binding affinity between the PH domain and PIP(2). PLC-gamma1 is substantially activated in the presence of EF-1alpha with a bell-shaped curve in relation to the molar ratio between them, whereas a double point mutant PLC-gamma1 (Y509A/F510A) that lost its binding affinity to EF-1alpha shows basal level activity. Taken together, our data show that EF-1alpha plays a direct role in phosphoinositide metabolism of cellular signaling by regulating PLC-gamma1 activity via a split PH domain.
Collapse
Affiliation(s)
- Jong-Soo Chang
- Department of Life Science, College of Natural Science, Daejin University, Kyeonggido 487-711, Korea.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Furukawa R, Jinks TM, Tishgarten T, Mazzawi M, Morris DR, Fechheimer M. Elongation factor 1beta is an actin-binding protein. BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1527:130-40. [PMID: 11479029 DOI: 10.1016/s0304-4165(01)00157-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
A 17 kDa polypeptide found in association with actin in cellular extracts of Dictyostelium discoideum was identified as a proteolytic fragment of eEF1beta. Antibody elicited against the 17 kDa protein reacted with a single 29 kDa polypeptide in Dictyostelium, indicating that the 17 kDa peptide arises from degradation of a larger precursor. The cDNA isolated from a Dictyostelium library using this antibody as a probe encodes Dictyostelium elongation factor 1beta. Amino acid degradation of the 17 kDa protein fragment confirmed the identity of the protein as eEF1beta. Direct interaction of eEF1beta with actin in vitro was further demonstrated in mixtures of actin with the 17 kDa protein fragment of Dictyostelium eEF1beta, recombinant preparations of Dictyostelium eEF1beta expressed in Escherichia coli, and the intact eEF1betagamma complex purified from wheat germ. Localization of eEF1beta in Dictyostelium by immunofluorescence microscopy reveals both diffuse cytoplasmic staining, and some concentration in the cortical and hyaline cytoplasm. The results support the existence of physical and functional interactions of the translation apparatus with the cytoskeleton, and suggest that eEF1beta may function in a dual role both to promote the elongation phase of protein synthesis, and to interact with cytoplasmic actin.
Collapse
Affiliation(s)
- R Furukawa
- Department of Cellular Biology, University of Georgia, 724 Biological Science Building, Athens, GA 30602, USA
| | | | | | | | | | | |
Collapse
|
36
|
Silar P, Lalucque H, Haedens V, Zickler D, Picard M. eEF1A Controls ascospore differentiation through elevated accuracy, but controls longevity and fruiting body formation through another mechanism in Podospora anserina. Genetics 2001; 158:1477-89. [PMID: 11514440 PMCID: PMC1461745 DOI: 10.1093/genetics/158.4.1477] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Antisuppressor mutations in the eEF1A gene of Podospora anserina were previously shown to impair ascospore formation, to drastically increase life span, and to permit the development of the Crippled Growth degenerative process. Here, we show that eEF1A controls ascospore formation through accuracy level maintenance. Examination of antisuppressor mutant perithecia reveals two main cytological defects, mislocalization of spindle and nuclei and nuclear death. Antisuppression levels are shown to be highly dependent upon both the mutation site and the suppressor used, precluding any correlation between antisuppression efficiency and severity of the sporulation impairment. Nevertheless, severity of ascospore differentiation defect is correlated with resistance to paromomycin. We also show that eEF1A controls fruiting body formation and longevity through a mechanism(s) different from accuracy control. In vivo, GFP tagging of the protein in a way that partly retains its function confirmed earlier cytological observation; i.e., this factor is mainly diffuse within the cytosol, but may transiently accumulate within nuclei or in defined regions of the cytoplasm. These data emphasize the fact that the translation apparatus exerts a global regulatory control over cell physiology and that eEF1A is one of the key factors involved in this monitoring.
Collapse
Affiliation(s)
- P Silar
- Institut de Génétique et Microbiologie de l'Université de Paris Sud, C.N.R.S. UMR 8621, 91405 Orsay Cedex, France.
| | | | | | | | | |
Collapse
|
37
|
Gungabissoon RA, Khan S, Hussey PJ, Maciver SK. Interaction of elongation factor 1alpha from Zea mays (ZmEF-1alpha) with F-actin and interplay with the maize actin severing protein, ZmADF3. CELL MOTILITY AND THE CYTOSKELETON 2001; 49:104-11. [PMID: 11443740 DOI: 10.1002/cm.1024] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
EF-1alpha is an abundant eukaryotic protein whose principle function appears to be to bind aminoacyl-tRNA to the ribosome. However, it is also known that EF-1alpha from other sources binds both microtubules and microfilaments. We report the expression of Zea mays EF-1alpha (ZmEF-1alpha) in bacteria and that this protein has similar actin-binding properties as other EF-1alpha members. ZmEF-1alpha bundles actin filaments at low pH (6.5) and inhibits the addition of monomer at both filament ends, possibly as a consequence. ZmEF-1alpha binds actin filaments at all pH values tested (pH 6.0-8.0), indicating that one actin binding site is not pH sensitive. One of the actin-binding sites was determined to reside within domain I (1-223) of ZmEF-1alpha, but this domain did not affect the kinetics of polymerisation. We show that the bundling activity of ZmEF-1alpha is modulated by ZmADF3 a (a Zea mays ADF/cofilin), an actin filament severing protein, in vitro. Bundling of actin filaments caused by ZmEF-1alpha was enhanced in the presence of ZmADF3. The pH-dependent activities of both proteins in vitro suggests that they may work together to respond to temporal and spatial intracellular pH changes to regulate the pattern of the growth of plant cells.
Collapse
Affiliation(s)
- R A Gungabissoon
- Genes and Development Group, Department of Biomedical Sciences, University of Edinburgh, Edinburgh, Scotland, United Kingdom
| | | | | | | |
Collapse
|
38
|
Elge S, Brearley C, Xia HJ, Kehr J, Xue HW, Mueller-Roeber B. An Arabidopsis inositol phospholipid kinase strongly expressed in procambial cells: synthesis of PtdIns(4,5)P2 and PtdIns(3,4,5)P3 in insect cells by 5-phosphorylation of precursors. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2001; 26:561-571. [PMID: 11489170 DOI: 10.1046/j.1365-313x.2001.01051.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We have cloned a phosphatidylinositol-4-phosphate 5-kinase (PIP5K) cDNA (AtP5K1) from Arabidopsis thaliana. By the application of cell permeabilization and short-term nonequilibrium labelling we show that expression of AtP5K1 in Baculovirus-infected insect (Spodoptera frugiperda) cells directs synthesis of PtdIns(4,5)P2 and PtdIns(3,4,5)P3. The same phosphoinositides were produced by isolated whole-cell membrane fractions of AtP5K1-expressing insect cells. Their synthesis was not affected by adding defined precursor lipids, that is PtdIns(3)P, PtdIns(4)P, PtdIns(3,4)P2, or PtdIns(4,5)P2, in excess, indicating that substrates for the plant enzyme were not limiting in vivo. Enzymatic dissection of lipid headgroups revealed that AtP5K1-directed synthesis of PtdIns(4,5)P2 and PtdIns(3,4,5)P3 proceeds via 5-phosphorylation of precursors. Analysis of promoter-reporter gene (beta-glucuronidase) fusions in transgenic plants revealed that expression of the AtP5K1 gene is strongest in vascular tissues of leaves, flowers, and roots, namely in cells of the lateral meristem, that is the procambium. Single-cell sampling of sap from flower stem meristem tissue and neighbouring phloem cells, when coupled to reverse transcriptase--polymerase chain reaction, confirmed preferential expression of AtP5K1 in procambial tissue. We hypothesize that AtP5K1, like animal and yeast PIP5K, may be involved in the control of cell proliferation.
Collapse
Affiliation(s)
- S Elge
- Max-Planck-Insitute of Molecular Plant Physiology, Am Mühlenberg 1, D-14476 Golm, Germany
| | | | | | | | | | | |
Collapse
|
39
|
Wang X, Woo YM, Kim CS, Larkins BA. Quantitative trait locus mapping of loci influencing elongation factor 1alpha content in maize endosperm. PLANT PHYSIOLOGY 2001; 125:1271-82. [PMID: 11244108 PMCID: PMC65607 DOI: 10.1104/pp.125.3.1271] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2000] [Revised: 12/06/2000] [Accepted: 12/27/2000] [Indexed: 05/22/2023]
Abstract
The nutritional value of maize (Zea mays) seed is most limited by its protein quality because its storage proteins are devoid of the essential amino acid lysine (Lys). The Lys content of the kernel can be significantly increased by the opaque-2 mutation, which reduces zein synthesis and increases accumulation of proteins that contain Lys. Elongation factor 1alpha (eEF1A) is one of these proteins, and its concentration is highly correlated with the Lys content of the endosperm. We investigated the genetic regulation of eEF1A and the basis for its relationship with other Lys-containing proteins by analyzing the progeny of a cross between a high (Oh51Ao2) and a low (Oh545o2) eEF1A maize inbred. We identified 83 simple sequence repeat loci that are polymorphic between these inbreds; the markers are broadly distributed over the genome (1,402 cM) with an average interval of 17 cM. Genotypic analysis of the F(2) progeny revealed two significant quantitative trait loci that account for 25% of the variance for eEF1A content. One of these is on the short arm of chromosome 4 and is linked with a cluster of 22-kD alpha-zein coding sequences; the other quantitative trait locus is on the long arm of chromosome 7. The content of alpha-zein and gamma-zein was measured in pools of high- and low-eEF1A individuals obtained from this cross, and a higher level of alpha-zein was found to cosegregate with high eEF1A content. Allelic variation at the 22-kD alpha-zein locus may contribute to the difference of eEF1A content between Oh51Ao2 and Oh545o2 by increasing the surface area of protein bodies in the endosperm and creating a more extensive network of cytoskeletal proteins.
Collapse
Affiliation(s)
- X Wang
- Department of Plant Sciences, University of Arizona, Tucson, AZ 85721, USA
| | | | | | | |
Collapse
|
40
|
Talukder AH, Jorgensen HF, Mandal M, Mishra SK, Vadlamudi RK, Clark BF, Mendelsohn J, Kumar R. Regulation of elongation factor-1alpha expression by growth factors and anti-receptor blocking antibodies. J Biol Chem 2001; 276:5636-42. [PMID: 11104760 DOI: 10.1074/jbc.m006824200] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The epidermal growth factor (EGF) family and its receptors regulate normal and cancerous epithelial cell proliferation, a process that could be suppressed by anti-receptor blocking antibodies. Polypeptide elongation factor-1alpha (EF-1alpha) is a multifunctional protein whose levels are positively correlated with the proliferative state of cells. To identify genes, whose expression may be modulated by anti-receptor blocking antibodies, we performed a differential display screening and isolated differentially expressed cDNAs. Isolates from one clone were 100% identical to human EF-1alpha. Both EGF and heregulin-beta1 (HRG) induced EF-1alpha promoter activity and mRNA and protein expression. Growth factor-mediated EF-1alpha expression was effectively blocked by pretreatment with humanized anti-EGF receptor antibody C225 or anti-human epidermal growth factor receptor-2 (HER2) antibody herceptin. Mutants and pharmacological inhibitors of p38(MAPK) and MEK, but not phosphatidylinositol 3-kinase, suppressed both constitutive and HRG-induced stimulation of EF-1alpha promoter activity in MCF-7 cells. Deletion analysis of the promoter suggested the requirement of the -393 to -204 region for growth factor-mediated transcription of EF-1alpha. Fine mapping and point mutation studies revealed a role of the SP1 site in the observed HRG-mediated regulation of the EF-1alpha promoter. In addition, we also provide new evidence to suggest that HRG stimulation of the EF-1alpha promoter involves increased physical interactions with acetylated histone H3 and histone H4. These results suggest that regulation of EF-1alpha expression by extracellular signals that function through human EGF receptor family members that are widely deregulated in human cancers and that growth factor regulation of EF-1alpha expression involve histone acetylation.
Collapse
Affiliation(s)
- A H Talukder
- Department of Molecular and Cellular Oncology, University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA
| | | | | | | | | | | | | | | |
Collapse
|
41
|
Lin Y, Seals DF, Randall SK, Yang Z. Dynamic localization of rop GTPases to the tonoplast during vacuole development. PLANT PHYSIOLOGY 2001; 125:241-51. [PMID: 11154333 PMCID: PMC61006 DOI: 10.1104/pp.125.1.241] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2000] [Accepted: 08/27/2000] [Indexed: 05/23/2023]
Abstract
Vacuoles are essential pleomorphic organelles that undergo dynamic changes during cell growth and differentiation in plants. How developmental signals are linked to vacuole biogenesis and development is poorly understood. In this report, we show that a Rop GTPase is localized to developing vacuoles in pea (Pisum sativum cv Extra Early Alaska). Rop belongs to the RHO family of Ras-related small GTP-binding proteins that are key molecular switches in a wide variety of eukaryotic signal transduction pathways. Using indirect immunofluorescence and an anti-Rop antibody, we showed that Rop proteins accumulate to high levels in rapidly growing tapetal cells of pea anthers. In these cells, Rop is localized to an endomembrane system that exists as dynamic pleomorphic networks: a perinuclear fine network decorated with punctate dots, a network composed of small spheres and tubules, and interconnected chambers. Colocalization with a tonoplast annexin VCaB42 shows that these dynamic networks represent the tonoplast. Our results suggest that the dynamic Rop-containing tonoplast networks represent a unique stage of vacuole development. The specific localization of Rop to developing vacuoles supports a role for Rop in signal transduction that mediates vacuole development in plants.
Collapse
Affiliation(s)
- Y Lin
- Department of Botany and Plant Sciences, University of California, Riverside, California 92521, USA
| | | | | | | |
Collapse
|
42
|
Bischoff C, Kahns S, Lund A, Jørgensen HF, Praestegaard M, Clark BF, Leffers H. The human elongation factor 1 A-2 gene (EEF1A2): complete sequence and characterization of gene structure and promoter activity. Genomics 2000; 68:63-70. [PMID: 10950927 DOI: 10.1006/geno.2000.6271] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The eukaryotic elongation factor 1 A (eEF1A, formerly EF1alpha) is a key factor in protein synthesis, where it promotes the transfer of aminoacylated tRNAs to the A site of the ribosome. Two differentially expressed isoforms of eEF1A, designated eEF1A-1 and eEF1A-2, are found in mammals. Here we report the isolation and sequencing of the gene (HGMW-approved symbol EEF1A2) coding for the human eEF1A-2 isoform. Furthermore, we characterize the gene structure and the activity of the promoter. Isolation of overlapping clones from human libraries revealed that the human eEF1A-2 gene spans approximately 10 kb and consists of eight exons. The intron-exon boundaries of human EEF1A2 and EEF1A1 are conserved, yet the gene of the eEF1A-2 isoform is larger than the eEF1A-1 gene because of enlarged introns. Primer extension analysis identified the predominant transcription start site 166 bp upstream of the AUG codon. The start site maps to an adenine located within a consensus initiator element. Sequencing of a 2-kb 5'-flanking promoter region revealed no TATA element. However, several putative cis-regulatory elements were discovered. The 5'-promoter activity was characterized by transient transfection experiments. Progressive deletions of the upstream promoter region defined a minimal promoter region, ranging from -16 to +92, that is sufficient to drive transcription.
Collapse
Affiliation(s)
- C Bischoff
- IMSB, University of Aarhus, Gustav Wieds vej 10 C, Arhus C, 8000, Denmark
| | | | | | | | | | | | | |
Collapse
|
43
|
Moore RC, Durso NA, Cyr RJ. Elongation factor-1alpha stabilizes microtubules in a calcium/calmodulin-dependent manner. CELL MOTILITY AND THE CYTOSKELETON 2000; 41:168-80. [PMID: 9786091 DOI: 10.1002/(sici)1097-0169(1998)41:2<168::aid-cm7>3.0.co;2-a] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Elongation factor-1alpha (EF-1alpha), a highly conserved protein named for its role in protein translation, is also a microtubule-associated protein (MAP). We used high-resolution differential interference contrast microscopy to quantify the effect of substoichiometric amounts of EF-1alpha (isolated from Daucus carota) on the dynamic instability of microtubules assembled in vitro from either animal or plant tubulin. EF-1alpha modulates the dynamic behavior of microtubules assembled from either tubulin source, resulting in longer and more persistent microtubules. EF-1alpha, at a 1:20 molar ratio to tubulin, significantly (P < 0.05) reduces the frequency of catastrophe threefold and decreases shortening velocities almost twofold for microtubules assembled from animal tubulin. For microtubules assembled from plant tubulin, substoichiometric amounts of EF-1alpha significantly (P < 0.05) suppress the frequency of catastrophe greater than twofold and causes an almost threefold reduction in shortening velocities. Elongation velocities increase almost twofold and rescues, which are not observed in the absence of EF-1alpha, occur. In addition, calcium/calmodulin (Ca2+/CaM), which regulates the ability of EF-1alpha to bundle taxol-stabilized microtubules in vitro, also modulates the effect of EF-1alpha on the dynamic behavior of microtubules assembled in vitro from animal tubulin. Microtubule severing in the presence of EF-1alpha was never observed. These data support the hypothesis that EF-1alpha modulates the dynamic behavior of microtubules assembled in vitro in a Ca2+/CaM-dependent manner.
Collapse
Affiliation(s)
- R C Moore
- Department of Biology, Penn State University, University Park 16802, USA
| | | | | |
Collapse
|
44
|
Moore RC, Cyr RJ. Association between elongation factor-1alpha and microtubules in vivo is domain dependent and conditional. CELL MOTILITY AND THE CYTOSKELETON 2000; 45:279-92. [PMID: 10744861 DOI: 10.1002/(sici)1097-0169(200004)45:4<279::aid-cm4>3.0.co;2-4] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Although the precise definition for a microtubule-associated protein (MAP) has been the subject of debate, elongation factor-1alpha (EF-1alpha) fits the most basic criteria for a MAP [Durso and Cyr, 1994a]. It binds, bundles, stabilizes, and promotes the assembly of microtubules in vitro, and localizes to plant microtubule arrays in situ. In this study, the in vitro and in vivo association of EF-1alpha with microtubules was further investigated. Analysis of the in vitro binding data for EF-1alpha and microtubules indicates that EF-1alpha binds cooperatively to the microtubule lattice. In order to investigate the interaction of EF-1alpha with microtubules in vivo, GFP fusions to EF-1alpha or to EF-1alpha truncates were transiently expressed in living plant cells. Using this method, two putative microtubule-binding domains on EF-1alpha were identified: one in the N-terminal domain I and one in the C-terminal domain III. The binding of domain I to microtubules in vivo, like the binding of full-length EF-1alpha, is conditional, and requires incubation in weak, lipophilic organic acids. The binding of domain III to microtubules in vivo, however, is not conditional, and occurs under normal cellular regimes. Furthermore, domain III stabilizes cortical microtubules as determined by their resistance to the anti-microtubule herbicide, oryzalin. Because the accumulation of EF-1alpha onto microtubules is unconditional in the absence of domain I, we hypothesize that domain I negatively regulates the accumulation of EF-1alpha onto microtubules in vivo. This hypothesis is discussed in terms of possible regulatory mechanisms that could affect the accumulation of EF-1alpha onto microtubules within living cells.
Collapse
Affiliation(s)
- R C Moore
- Department of Biology and Intercollege Program in Plant Physiology, The Pennsylvania State University, University Park 16802, USA
| | | |
Collapse
|
45
|
Ransom-Hodgkins WD, Brglez I, Wang X, Boss WF. Calcium-regulated proteolysis of eEF1A. PLANT PHYSIOLOGY 2000; 122:957-65. [PMID: 10712560 PMCID: PMC58932 DOI: 10.1104/pp.122.3.957] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/1999] [Accepted: 11/23/1999] [Indexed: 05/23/2023]
Abstract
Eukaryotic elongation factor 1alpha (eEF1A) can be post-translationally modified by the addition of phosphorylglycerylethanolamine (PGE). [(14)C]Ethanolamine was incorporated into the PGE modification, and with carrot (Daucus carota L.) suspension culture cells, eEF1A was the only protein that incorporated detectable quantities of [(14)C]ethanolamine (Ransom et al., 1998). When 1 mM CaCl(2) was added to microsomes containing [(14)C]ethanolamine-labeled eEF1A ([(14)C]et-eEF1A), there was a 60% decrease in the amount of [(14)C]et-eEF1A recovered after 10 min. The loss of endogenous [(14)C]et-eEF1A was prevented by adding EGTA. Recombinant eEF1A, which did not contain the PGE modification, also was degraded by microsomes in a Ca(2+)-regulated manner, indicating that PGE modification was not necessary for proteolysis; however, it enabled us to quantify enodgenous eEF1A. By monitoring [(14)C]et-eEF1A, we found that treatment with phospholipase D or C, but not phospholipase A(2), resulted in a decrease in [(14)C]et-eEF1A from carrot microsomes. The fact that there was no loss of [(14)C]et-eEF1A with phospholipase A(2) treatment even in the presence of 1 mM Ca(2+) suggested that the loss of membrane lipids was not essential for eEF1A proteolysis and that lysolipids or fatty acids decreased proteolysis. At micromolar Ca(2+) concentrations, proteolysis of eEF1A was pH sensitive. When 1 microM CaCl(2) was added at pH 7.2, 35% of [(14)C]et-eEF1A was lost; while at pH 6.8, 10 microM CaCl(2) was required to give a similar loss of protein. These data suggest that eEF1A may be an important downstream target for Ca(2+) and lipid-mediated signal transduction cascades.
Collapse
Affiliation(s)
- W D Ransom-Hodgkins
- Botany Department, North Carolina State University, Raleigh, North Carolina 27695-7612, USA
| | | | | | | |
Collapse
|
46
|
Pical C, Westergren T, Dove SK, Larsson C, Sommarin M. Salinity and hyperosmotic stress induce rapid increases in phosphatidylinositol 4,5-bisphosphate, diacylglycerol pyrophosphate, and phosphatidylcholine in Arabidopsis thaliana cells. J Biol Chem 1999; 274:38232-40. [PMID: 10608898 DOI: 10.1074/jbc.274.53.38232] [Citation(s) in RCA: 155] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In animal cells, phosphoinositides are key components of the inositol 1,4,5-trisphosphate/diacylglycerol-based signaling pathway, but also have many other cellular functions. These lipids are also believed to fulfill similar functions in plant cells, although many details concerning the components of a plant phosphoinositide system, and their regulation are still missing. Only recently have the different phosphoinositide isomers been unambiguously identified in plant cells. Another problem that hinders the study of the function of phosphoinositides and their derivatives, as well as the regulation of their metabolism, in plant cells is the need for a homogenous, easily obtainable material, from which the extraction and purification of phospholipids is relatively easy and quantitatively reproducible. We present here a thorough characterization of the phospholipids purified from [(32)P]orthophosphate- and myo-[2-(3)H]inositol-radiolabeled Arabidopsis thaliana suspension-cultured cells. We then show that NaCl treatment induces dramatic increases in the levels of phosphatidylinositol 4,5-bisphosphate and diacylglycerol pyrophosphate and also affects the turnover of phosphatidylcholine. The increase in phosphatidylinositol 4,5-bisphosphate was also observed with a non-ionic hyperosmotic shock. In contrast, the increase in diacylglycerol pyrophosphate and the turnover of phosphatidylcholine were relatively specific to salt treatments as only minor changes in the metabolism of these two phospholipids were detected when the cells were treated with sorbitol instead of NaCl.
Collapse
Affiliation(s)
- C Pical
- Department of Plant Biochemistry, Lund University, SE-22100 Lund, Sweden
| | | | | | | | | |
Collapse
|
47
|
Khalyfa A, Carlson BM, Carlson JA, Wang E. Toxin injury-dependent switched expression between EF-1 alpha and its sister, S1, in rat skeletal muscle. Dev Dyn 1999; 216:267-73. [PMID: 10590478 DOI: 10.1002/(sici)1097-0177(199911)216:3<267::aid-dvdy5>3.0.co;2-v] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Elongation factor-1 alpha, (EF-1 alpha), a translation factor involved in peptide chain elongation, is found ubiquitously in all cells. Previously, we identified a highly homologous EF-1 alpha sister gene, S1, whose transcript is found in only three tissues: brain, heart, and muscle, where the tissue-specific expression of S1 is caused by its exclusive presence in cells such as neurons and myocytes. Using sequence-specific synthetic peptides, we have recently produced polyclonal antibodies that can distinguish the protein product of EF-1 alpha from that of its sister, S1. Results of Western blotting show that these two proteins appear in S1-positive muscle tissue in inverse relationship, i.e., when S1 protein is in abundance, EF-1 alpha protein is in contrast in low quantity, and vice versa. During early embryonic stages, EF-1 alpha is the predominant protein species, whereas S1 is hardly detectable. This high EF-1 alpha versus low S1 protein presence undergoes a switch in that by postnatal day 14, EF-1 alpha is scarce whereas S1 is abundant; thus, there is a development-dependent shift of EF-1 alpha/S1 ratio from high to low, and the low EF-1 alpha/S1 ratio is maintained in adulthood. In this report, we describe the reversal of the EF-1 alpha/S1 ratio from low to high during muscle injury (experimentally induced by Marcaine injection), and a return to the original low ratio once the injury is repaired by regeneration. In this injury condition, EF-1 alpha is rapidly upregulated immediately after the Marcaine treatment, possibly reflecting an injury-dependent response of regeneration. The increase of EF-1 alpha corresponds with a decrease of S1 protein presence, thus resulting in a change of EF-1 alpha/S1 ratio from low to high. However, the high EF-1 alpha/S1 ratio eventually reverts to low, when regeneration-associated proliferation ceases, and fully differentiated myotubes are reestablished in the injured cells. This result shows that: (1) a high EF-1 alpha/S1 ratio is an early molecular diagnostic marker for injury-elicited regeneration; and (2) when injury repair is accomplished, there is a reversion to the low EF-1 alpha/S1 ratio, reflecting the restoration of the muscle fiber to the preinjury functional status. Results presented here not only show that a high EF-1 alpha/S1 ratio is a molecular marker for injured muscle, but also reveal the underpinning translational regulation in muscle during injury.
Collapse
Affiliation(s)
- A Khalyfa
- Bloomfield Center for Research in Aging, Lady Davis Institute for Medical Research, Sir Mortimer B. Davis-Jewish General Hospital, McGill University, Montréal, Quebéc, Canada
| | | | | | | |
Collapse
|
48
|
Guillén G, Valdés-López V, Noguez R, Olivares J, Rodríguez-Zapata LC, Pérez H, Vidali L, Villanueva MA, Sánchez F. Profilin in Phaseolus vulgaris is encoded by two genes (only one expressed in root nodules) but multiple isoforms are generated in vivo by phosphorylation on tyrosine residues. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 1999; 19:497-508. [PMID: 10504572 DOI: 10.1046/j.1365-313x.1999.00542.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Actin-binding proteins such as profilins participate in the restructuration of the actin cytoskeleton in plant cells. Profilins are ubiquitous actin-, polyproline-, and inositol phospholipid-binding proteins, which in plants are encoded by multigene families. By 2D-PAGE and immunoblotting, we detected as much as five profilin isoforms in crude extracts from nodules of Phaseolus vulgaris. However, by immunoprecipitation and gel electrophoresis of in vitro translation products from nodule RNA, only the most basic isoform of those found in nodule extracts, was detected. Furthermore, a bean profilin cDNA probe hybridised to genomic DNA digested with different restriction enzymes, showed either a single or two bands. These data indicate that profilin in P. vulgaris is encoded by only two genes. In root nodules only one gene is expressed, and a single profilin transcript gives rise to multiple profilin isoforms by post-translational modifications of the protein. By in vivo 32P-labelling and immunoprecipitation with both, antiprofilin and antiphosphotyrosine-specific antibodies, we found that profilin is phosphorylated on tyrosine residues. Since chemical (TLC) and immunological analyses, as well as plant tyrosine phosphatase (AtPTP1) treatments of profilin indicated that tyrosine residues were phosphorylated, we concluded that tyrosine kinases must exist in plants. This finding will focus research on tyrosine kinases/tyrosine phosphatases that could participate in novel regulatory functions/pathways, involving not only this multifunctional cytoskeletal protein, but other plant proteins.
Collapse
Affiliation(s)
- G Guillén
- Plant Molecular Biology Department, Institute of Biotechnology UNAM, Cuernavaca, Orelos, Mexico
| | | | | | | | | | | | | | | | | |
Collapse
|
49
|
Drøbak BK, Dewey RE, Boss WF. Phosphoinositide kinases and the synthesis of polyphosphoinositides in higher plant cells. INTERNATIONAL REVIEW OF CYTOLOGY 1999; 189:95-130. [PMID: 10333579 DOI: 10.1016/s0074-7696(08)61386-8] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
Phosphoinositides are a family of inositol-containing phospholipids which are present in all eukaryotic cells. Although in most cells these lipids, with the exception of phosphatidylinositol, constitute only a very minor proportion of total cellular lipids, they have received immense attention by researchers in the past 15-20 years. This is due to the discovery that these lipids, rather than just having structural functions, play key roles in a wide range of important cellular processes. Much less is known about the plant phosphoinositides than about their mammalian counterparts. However, it has been established that a functional phosphoinositide system exists in plant cells and it is becoming increasingly clear that inositol-containing lipids are likely to play many important roles throughout the life of a plant. It is not our intention to give an exhaustive overview of all aspects of the field, but rather we focus on the phosphoinositide kinases responsible for the synthesis of all phosphorylated forms of phosphatidylinositol. Also, we mention some of the aspects of current phosphoinositide research which, in our opinion, are most likely to provide a suitable starting point for further research into the role of phosphoinositides in plants.
Collapse
Affiliation(s)
- B K Drøbak
- Department of Cell Biology, John Innes Centre, Norwich, United Kingdom
| | | | | |
Collapse
|
50
|
Xue HW, Pical C, Brearley C, Elge S, Müller-Röber B. A plant 126-kDa phosphatidylinositol 4-kinase with a novel repeat structure. Cloning and functional expression in baculovirus-infected insect cells. J Biol Chem 1999; 274:5738-45. [PMID: 10026194 DOI: 10.1074/jbc.274.9.5738] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Phosphatidylinositol metabolism plays a central role in signaling pathways in animals and is also believed to be of importance in signal transduction in higher plants. We report here the molecular cloning of a cDNA encoding a previously unidentified 126-kDa phosphatidylinositol (PI) 4-kinase (AtPI4Kbeta) from the higher plant Arabidopsis thaliana. The novel protein possesses the conserved domains present in animal and yeast PI 4-kinases, namely a lipid kinase unique domain and a catalytic domain. An additional domain, approximately 300 amino acids long, containing a high percentage (46%) of charged amino acids is specific to this plant enzyme. Recombinant AtPI4Kbeta expressed in baculovirus-infected insect (Spodoptera frugiperda) cells phosphorylated phosphatidylinositol exclusively at the D4 position of the inositol ring. Recombinant protein was maximally activated by 0.6% Triton X-100 but was inhibited by adenosine with an IC50 of approximately 200 microM. Wortmannin at a concentration of 10 microM inhibited AtPI4Kbeta activity by approximately 90%. AtPI4Kbeta transcript levels were similar in all tissues analyzed. Light or treatment with hormones or salts did not change AtPI4Kbeta transcript levels to a great extent, indicating constitutive expression of the AtPI4Kbeta gene.
Collapse
Affiliation(s)
- H W Xue
- Max Planck Institute of Molecular Plant Physiology, Karl-Liebknecht-Strabetae 25, Haus 20, D-14476 Golm/Potsdam, Germany
| | | | | | | | | |
Collapse
|