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Heidari B, Nemie-Feyissa D, Lillo C. Distinct Clades of Protein Phosphatase 2A Regulatory B'/B56 Subunits Engage in Different Physiological Processes. Int J Mol Sci 2023; 24:12255. [PMID: 37569631 PMCID: PMC10418862 DOI: 10.3390/ijms241512255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 07/27/2023] [Accepted: 07/28/2023] [Indexed: 08/13/2023] Open
Abstract
Protein phosphatase 2A (PP2A) is a strongly conserved and major protein phosphatase in all eukaryotes. The canonical PP2A complex consists of a catalytic (C), scaffolding (A), and regulatory (B) subunit. Plants have three groups of evolutionary distinct B subunits: B55, B' (B56), and B''. Here, the Arabidopsis B' group is reviewed and compared with other eukaryotes. Members of the B'α/B'β clade are especially important for chromatid cohesion, and dephosphorylation of transcription factors that mediate brassinosteroid (BR) signaling in the nucleus. Other B' subunits interact with proteins at the cell membrane to dampen BR signaling or harness immune responses. The transition from vegetative to reproductive phase is influenced differentially by distinct B' subunits; B'α and B'β being of little importance, whereas others (B'γ, B'ζ, B'η, B'θ, B'κ) promote transition to flowering. Interestingly, the latter B' subunits have three motifs in a conserved manner, i.e., two docking sites for protein phosphatase 1 (PP1), and a POLO consensus phosphorylation site between these motifs. This supports the view that a conserved PP1-PP2A dephosphorelay is important in a variety of signaling contexts throughout eukaryotes. A profound understanding of these regulators may help in designing future crops and understand environmental issues.
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Affiliation(s)
| | | | - Cathrine Lillo
- IKBM, Department of Chemistry, Bioscience and Environmental Engineering, University of Stavanger, 4036 Stavanger, Norway; (B.H.); (D.N.-F.)
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Zhang G, Zhang Z, Luo S, Li X, Lyu J, Liu Z, Wan Z, Yu J. Genome-wide identification and expression analysis of the cucumber PP2C gene family. BMC Genomics 2022; 23:563. [PMID: 35933381 PMCID: PMC9356470 DOI: 10.1186/s12864-022-08734-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Accepted: 06/30/2022] [Indexed: 11/13/2022] Open
Abstract
Background Type 2C protein phosphatase (PP2C) is a negative regulator of ABA signaling pathway, which plays important roles in stress signal transduction in plants. However, little research on the PP2C genes family of cucumber (Cucumis sativus L.), as an important economic vegetable, has been conducted. Results This study conducted a genome-wide investigation of the CsPP2C gene family. Through bioinformatics analysis, 56 CsPP2C genes were identified in cucumber. Based on phylogenetic analysis, the PP2C genes of cucumber and Arabidopsis were divided into 13 groups. Gene structure and conserved motif analysis showed that CsPP2C genes in the same group had similar gene structure and conserved domains. Collinearity analysis showed that segmental duplication events played a key role in the expansion of the cucumber PP2C genes family. In addition, the expression of CsPP2Cs under different abiotic treatments was analyzed by qRT-PCR. The results reveal that CsPP2C family genes showed different expression patterns under ABA, drought, salt, and cold treatment, and that CsPP2C3, 11–17, 23, 45, 54 and 55 responded significantly to the four stresses. By predicting the cis-elements in the promoter, we found that all CsPP2C members contained ABA response elements and drought response elements. Additionally, the expression patterns of CsPP2C genes were specific in different tissues. Conclusions The results of this study provide a reference for the genome-wide identification of the PP2C gene family in other species and provide a basis for future studies on the function of PP2C genes in cucumber. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-022-08734-y.
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Affiliation(s)
- Guobin Zhang
- State Key Laboratory of Aridland Crop Science, Gansu Agricultural University, Lanzhou, 730070, China.,College of Horticulture, Gansu Agricultural University, Lanzhou, 730070, China
| | - Zeyu Zhang
- College of Horticulture, Gansu Agricultural University, Lanzhou, 730070, China
| | - Shilei Luo
- State Key Laboratory of Aridland Crop Science, Gansu Agricultural University, Lanzhou, 730070, China.,College of Horticulture, Gansu Agricultural University, Lanzhou, 730070, China
| | - Xia Li
- Gansu Institute of Geological and Natural Disaster Prevention, Lanzhou, 730000, China
| | - Jian Lyu
- College of Horticulture, Gansu Agricultural University, Lanzhou, 730070, China
| | - Zeci Liu
- College of Horticulture, Gansu Agricultural University, Lanzhou, 730070, China
| | - Zilong Wan
- College of Horticulture, Gansu Agricultural University, Lanzhou, 730070, China
| | - Jihua Yu
- State Key Laboratory of Aridland Crop Science, Gansu Agricultural University, Lanzhou, 730070, China. .,College of Horticulture, Gansu Agricultural University, Lanzhou, 730070, China.
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Qiu J, Ni L, Xia X, Chen S, Zhang Y, Lang M, Li M, Liu B, Pan Y, Li J, Zhang X. Genome-Wide Analysis of the Protein Phosphatase 2C Genes in Tomato. Genes (Basel) 2022; 13:genes13040604. [PMID: 35456410 PMCID: PMC9032827 DOI: 10.3390/genes13040604] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Revised: 03/23/2022] [Accepted: 03/24/2022] [Indexed: 01/27/2023] Open
Abstract
The plant protein phosphatase 2C (PP2C) plays an irreplaceable role in phytohormone signaling, developmental processes, and manifold stresses. However, information about the PP2C gene family in tomato (Solanum lycopersicum) is relatively restricted. In this study, a genome-wide investigation of the SlPP2C gene family was performed. A total of 92 SlPP2C genes were identified, they were distributed on 11 chromosomes, and all the SlPP2C proteins have the type 2C phosphatase domains. Based on phylogenetic analysis of PP2C genes in Arabidopsis, rice, and tomato, SlPP2C genes were divided into eight groups, designated A–H, which is also supported by the analyses of gene structures and protein motifs. Gene duplication analysis revealed that the duplication of whole genome and chromosome segments was the main cause of SLPP2Cs expansion. A total of 26 cis-elements related to stress, hormones, and development were identified in the 3 kb upstream region of these SlPP2C genes. Expression profile analysis revealed that the SlPP2C genes display diverse expression patterns in various tomato tissues. Furthermore, we investigated the expression patterns of SlPP2C genes in response to Ralstonia solanacearum infection. RNA-seq and qRT-PCR data reveal that nine SlPP2Cs are correlated with R. solanacearum. The above evidence hinted that SlPP2C genes play multiple roles in tomato and may contribute to tomato resistance to bacterial wilt. This study obtained here will give an impetus to the understanding of the potential function of SlPP2Cs and lay a solid foundation for tomato breeding and transgenic resistance to plant pathogens.
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Affiliation(s)
- Jianfang Qiu
- Key Laboratory of Horticulture Science for Southern Mountainous Regions, The Ministry of Education, College of Horticulture and Landscape Architecture, Southwest University, No. 2 Tiansheng Road, Beibei, Chongqing 400715, China; (J.Q.); (L.N.); (X.X.); (S.C.); (Y.Z.); (M.L.); (M.L.); (B.L.); (Y.P.); (J.L.)
- State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Academy of Agricultural Sciences, Southwest University, Beibei, Chongqing 400715, China
| | - Lei Ni
- Key Laboratory of Horticulture Science for Southern Mountainous Regions, The Ministry of Education, College of Horticulture and Landscape Architecture, Southwest University, No. 2 Tiansheng Road, Beibei, Chongqing 400715, China; (J.Q.); (L.N.); (X.X.); (S.C.); (Y.Z.); (M.L.); (M.L.); (B.L.); (Y.P.); (J.L.)
- State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Academy of Agricultural Sciences, Southwest University, Beibei, Chongqing 400715, China
| | - Xue Xia
- Key Laboratory of Horticulture Science for Southern Mountainous Regions, The Ministry of Education, College of Horticulture and Landscape Architecture, Southwest University, No. 2 Tiansheng Road, Beibei, Chongqing 400715, China; (J.Q.); (L.N.); (X.X.); (S.C.); (Y.Z.); (M.L.); (M.L.); (B.L.); (Y.P.); (J.L.)
- State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Academy of Agricultural Sciences, Southwest University, Beibei, Chongqing 400715, China
| | - Shihao Chen
- Key Laboratory of Horticulture Science for Southern Mountainous Regions, The Ministry of Education, College of Horticulture and Landscape Architecture, Southwest University, No. 2 Tiansheng Road, Beibei, Chongqing 400715, China; (J.Q.); (L.N.); (X.X.); (S.C.); (Y.Z.); (M.L.); (M.L.); (B.L.); (Y.P.); (J.L.)
- State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Academy of Agricultural Sciences, Southwest University, Beibei, Chongqing 400715, China
| | - Yan Zhang
- Key Laboratory of Horticulture Science for Southern Mountainous Regions, The Ministry of Education, College of Horticulture and Landscape Architecture, Southwest University, No. 2 Tiansheng Road, Beibei, Chongqing 400715, China; (J.Q.); (L.N.); (X.X.); (S.C.); (Y.Z.); (M.L.); (M.L.); (B.L.); (Y.P.); (J.L.)
- State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Academy of Agricultural Sciences, Southwest University, Beibei, Chongqing 400715, China
| | - Min Lang
- Key Laboratory of Horticulture Science for Southern Mountainous Regions, The Ministry of Education, College of Horticulture and Landscape Architecture, Southwest University, No. 2 Tiansheng Road, Beibei, Chongqing 400715, China; (J.Q.); (L.N.); (X.X.); (S.C.); (Y.Z.); (M.L.); (M.L.); (B.L.); (Y.P.); (J.L.)
| | - Mengyu Li
- Key Laboratory of Horticulture Science for Southern Mountainous Regions, The Ministry of Education, College of Horticulture and Landscape Architecture, Southwest University, No. 2 Tiansheng Road, Beibei, Chongqing 400715, China; (J.Q.); (L.N.); (X.X.); (S.C.); (Y.Z.); (M.L.); (M.L.); (B.L.); (Y.P.); (J.L.)
- State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Academy of Agricultural Sciences, Southwest University, Beibei, Chongqing 400715, China
| | - Binman Liu
- Key Laboratory of Horticulture Science for Southern Mountainous Regions, The Ministry of Education, College of Horticulture and Landscape Architecture, Southwest University, No. 2 Tiansheng Road, Beibei, Chongqing 400715, China; (J.Q.); (L.N.); (X.X.); (S.C.); (Y.Z.); (M.L.); (M.L.); (B.L.); (Y.P.); (J.L.)
- State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Academy of Agricultural Sciences, Southwest University, Beibei, Chongqing 400715, China
| | - Yu Pan
- Key Laboratory of Horticulture Science for Southern Mountainous Regions, The Ministry of Education, College of Horticulture and Landscape Architecture, Southwest University, No. 2 Tiansheng Road, Beibei, Chongqing 400715, China; (J.Q.); (L.N.); (X.X.); (S.C.); (Y.Z.); (M.L.); (M.L.); (B.L.); (Y.P.); (J.L.)
- State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Academy of Agricultural Sciences, Southwest University, Beibei, Chongqing 400715, China
| | - Jinhua Li
- Key Laboratory of Horticulture Science for Southern Mountainous Regions, The Ministry of Education, College of Horticulture and Landscape Architecture, Southwest University, No. 2 Tiansheng Road, Beibei, Chongqing 400715, China; (J.Q.); (L.N.); (X.X.); (S.C.); (Y.Z.); (M.L.); (M.L.); (B.L.); (Y.P.); (J.L.)
- State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Academy of Agricultural Sciences, Southwest University, Beibei, Chongqing 400715, China
| | - Xingguo Zhang
- Key Laboratory of Horticulture Science for Southern Mountainous Regions, The Ministry of Education, College of Horticulture and Landscape Architecture, Southwest University, No. 2 Tiansheng Road, Beibei, Chongqing 400715, China; (J.Q.); (L.N.); (X.X.); (S.C.); (Y.Z.); (M.L.); (M.L.); (B.L.); (Y.P.); (J.L.)
- State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Academy of Agricultural Sciences, Southwest University, Beibei, Chongqing 400715, China
- Correspondence: ; Tel.: +86-23-68250974; Fax: +86-23-68251274
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Fan K, Chen Y, Mao Z, Fang Y, Li Z, Lin W, Zhang Y, Liu J, Huang J, Lin W. Pervasive duplication, biased molecular evolution and comprehensive functional analysis of the PP2C family in Glycine max. BMC Genomics 2020; 21:465. [PMID: 32631220 PMCID: PMC7339511 DOI: 10.1186/s12864-020-06877-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Accepted: 07/01/2020] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Soybean (Glycine max) is an important oil provider and ecosystem participant. The protein phosphatase 2C (PP2C) plays important roles in key biological processes. Molecular evolution and functional analysis of the PP2C family in soybean are yet to be reported. RESULTS The present study identified 134 GmPP2Cs with 10 subfamilies in soybean. Duplication events were prominent in the GmPP2C family, and all duplicated gene pairs were involved in the segmental duplication events. The legume-common duplication event and soybean-specific tetraploid have primarily led to expanding GmPP2C members in soybean. Sub-functionalization was the main evolutionary fate of duplicated GmPP2C members. Meanwhile, massive genes were lost in the GmPP2C family, especially from the F subfamily. Compared with other genes, the evolutionary rates were slower in the GmPP2C family. The PP2C members from the H subfamily resembled their ancestral genes. In addition, some GmPP2Cs were identified as the putative key regulator that could control plant growth and development. CONCLUSIONS A total of 134 GmPP2Cs were identified in soybean, and their expansion, molecular evolution and putative functions were comprehensively analyzed. Our findings provided the detailed information on the evolutionary history of the GmPP2C family, and the candidate genes can be used in soybean breeding.
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Affiliation(s)
- Kai Fan
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002 P. R. China
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002 P. R. China
- Key Laboratory of Crop Ecology and Molecular Physiology (Fujian Agriculture and Forestry University), Fujian Province University, Fuzhou, 35002 P. R. China
| | - Yunrui Chen
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002 P. R. China
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002 P. R. China
- Key Laboratory of Crop Ecology and Molecular Physiology (Fujian Agriculture and Forestry University), Fujian Province University, Fuzhou, 35002 P. R. China
| | - Zhijun Mao
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002 P. R. China
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002 P. R. China
- Key Laboratory of Crop Ecology and Molecular Physiology (Fujian Agriculture and Forestry University), Fujian Province University, Fuzhou, 35002 P. R. China
| | - Yao Fang
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002 P. R. China
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002 P. R. China
- Key Laboratory of Crop Ecology and Molecular Physiology (Fujian Agriculture and Forestry University), Fujian Province University, Fuzhou, 35002 P. R. China
| | - Zhaowei Li
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002 P. R. China
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002 P. R. China
- Key Laboratory of Crop Ecology and Molecular Physiology (Fujian Agriculture and Forestry University), Fujian Province University, Fuzhou, 35002 P. R. China
| | - Weiwei Lin
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002 P. R. China
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002 P. R. China
- Key Laboratory of Crop Ecology and Molecular Physiology (Fujian Agriculture and Forestry University), Fujian Province University, Fuzhou, 35002 P. R. China
| | - Yongqiang Zhang
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002 P. R. China
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002 P. R. China
- Key Laboratory of Crop Ecology and Molecular Physiology (Fujian Agriculture and Forestry University), Fujian Province University, Fuzhou, 35002 P. R. China
| | - Jianping Liu
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002 P. R. China
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002 P. R. China
- Key Laboratory of Crop Ecology and Molecular Physiology (Fujian Agriculture and Forestry University), Fujian Province University, Fuzhou, 35002 P. R. China
| | - Jinwen Huang
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002 P. R. China
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002 P. R. China
- Key Laboratory of Crop Ecology and Molecular Physiology (Fujian Agriculture and Forestry University), Fujian Province University, Fuzhou, 35002 P. R. China
| | - Wenxiong Lin
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002 P. R. China
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002 P. R. China
- Key Laboratory of Crop Ecology and Molecular Physiology (Fujian Agriculture and Forestry University), Fujian Province University, Fuzhou, 35002 P. R. China
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Fan K, Yuan S, Chen J, Chen Y, Li Z, Lin W, Zhang Y, Liu J, Lin W. Molecular evolution and lineage-specific expansion of the PP2C family in Zea mays. PLANTA 2019; 250:1521-1538. [PMID: 31346803 DOI: 10.1007/s00425-019-03243-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 07/16/2019] [Indexed: 05/19/2023]
Abstract
97 ZmPP2Cs were clustered into 10 subfamilies with biased subfamily evolution and lineage-specific expansion. Segmental duplication after the divergence of maize and sorghum might have led to primary expansion of ZmPP2Cs. The protein phosphatase 2C (PP2C) enzymes control many stress responses and developmental processes in plants. In Zea mays, a comprehensive understanding of the evolution and expansion of the PP2C family is still lacking. In the current study, 97 ZmPP2Cs were identified and clustered into 10 subfamilies. Through the analysis of the PP2C family in monocots, the ZmPP2C subfamilies displayed biased subfamily molecular evolution and lineage-specific expansion, as evidenced by their differing numbers of member genes, expansion and evolutionary rates, conserved subdomains, chromosomal distributions, expression levels, responsive-regulatory elements and regulatory networks. Moreover, while segmental duplication events have caused the primary expansion of the ZmPP2Cs, the majority of their diversification occurred following the additional whole-genome duplication that took place after the divergence of maize and sorghum (Sorghum bicolor). After this event, the PP2C subfamilies showed asymmetric evolutionary rates, with the D, F2 and H subfamily likely the most closely to resemble its ancestral subfamily's genes. These findings could provide novel insights into the molecular evolution and expansion of the PP2C family in maize, and lay the foundation for the functional analysis of these enzymes in maize and related monocots.
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Affiliation(s)
- Kai Fan
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Crop Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- Key Laboratory of Crop Ecology and Molecular Physiology (Fujian Agriculture and Forestry University), Fujian Province University, Fuzhou, 35002, China
| | - Shuna Yuan
- Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences/Danzhou Investigation and Experiment Station of Tropical Crops, Ministry of Agriculture, Danzhou, 571737, China
| | - Jie Chen
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Crop Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- Key Laboratory of Crop Ecology and Molecular Physiology (Fujian Agriculture and Forestry University), Fujian Province University, Fuzhou, 35002, China
| | - Yunrui Chen
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Crop Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- Key Laboratory of Crop Ecology and Molecular Physiology (Fujian Agriculture and Forestry University), Fujian Province University, Fuzhou, 35002, China
| | - Zhaowei Li
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- Key Laboratory of Crop Ecology and Molecular Physiology (Fujian Agriculture and Forestry University), Fujian Province University, Fuzhou, 35002, China
| | - Weiwei Lin
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- Key Laboratory of Crop Ecology and Molecular Physiology (Fujian Agriculture and Forestry University), Fujian Province University, Fuzhou, 35002, China
| | - Yongqiang Zhang
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- Key Laboratory of Crop Ecology and Molecular Physiology (Fujian Agriculture and Forestry University), Fujian Province University, Fuzhou, 35002, China
| | - Jianping Liu
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- Key Laboratory of Crop Ecology and Molecular Physiology (Fujian Agriculture and Forestry University), Fujian Province University, Fuzhou, 35002, China
| | - Wenxiong Lin
- Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, College of Crop Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.
- Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.
- Key Laboratory of Crop Ecology and Molecular Physiology (Fujian Agriculture and Forestry University), Fujian Province University, Fuzhou, 35002, China.
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Cao Q, Rediske RR, Yao L, Xie L. Effect of microcystins on root growth, oxidative response, and exudation of rice (Oryza sativa). ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2018; 149:143-149. [PMID: 29156306 DOI: 10.1016/j.ecoenv.2017.11.020] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 11/02/2017] [Accepted: 11/09/2017] [Indexed: 06/07/2023]
Abstract
A 30 days indoor hydroponic experiment was carried out to evaluate the effect of microcystins (MCs) on rice root morphology and exudation, as well as bioaccumulation of MCs in rice. MCs were bioaccumulated in rice with the greatest concentrations being observed in the leaves (113.68μgg-1 Fresh weight (FW)) when exposed to 500μgL-1 MCs. Root activity at 500μgL-1 decreased 37%, compared to the control. MCs also induced disruption of the antioxidant system and lipid peroxidation in rice roots. Root growth was significantly inhibited by MCs. Root weight, length; surface area and volume were significantly decreased, as well as crown root number and lateral root number. After 30 days exposure to MCs, an increase was found in tartaric acid and malic acid while the other organic acids were not affected. Glycine, tyrosine, and glutamate were the only amino acids stimulated at MCs concentrations of 500μgL-1. Similarly, dissolved organic carbon (DOC) and carbohydrate at 50 and 500μgL-1 treatments were significantly increased. The increase of DOC and carbohydrate in root exudates was due to rice root membrane permeability changes induced by MCs. Overall, this study indicated that MCs significantly inhibited rice root growth and affected root exudation.
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Affiliation(s)
- Qing Cao
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Richard R Rediske
- Annis Water Resources Institute, Grand Valley State University, 740 West Shoreline Drive, Muskegon, MI 49441, USA
| | - Lei Yao
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Liqiang Xie
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing 210008, China.
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Chen C, Yu Y, Ding X, Liu B, Duanmu H, Zhu D, Sun X, Cao L, Zaib-Un-Nisa, Li Q, Zhu Y. Genome-wide analysis and expression profiling of PP2C clade D under saline and alkali stresses in wild soybean and Arabidopsis. PROTOPLASMA 2018; 255:643-654. [PMID: 29052008 DOI: 10.1007/s00709-017-1172-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 10/02/2017] [Indexed: 06/07/2023]
Abstract
Protein phosphatase 2Cs (PP2Cs) belong to the largest protein phosphatase family in plants. Some members have been described as being negative modulators of plant growth and development, as well as responses to hormones and environmental stimuli. However, little is known about the members of PP2C clade D, which may be involved in the regulation of signaling pathways, especially in response to saline and alkali stresses. Here, we identified 13 PP2C orthologs from the wild soybean (Glycine soja) genome. We examined the sequence characteristics, chromosome locations and duplications, gene structures, and promoter cis-elements of the PP2C clade D genes in Arabidopsis and wild soybean. Our results showed that GsPP2C clade D (GsAPD) genes exhibit more gene duplications than AtPP2C clade D genes. Plant hormone and abiotic stress-responsive elements were identified in the promoter regions of most PP2C genes. Moreover, we investigated their expression patterns in roots, stems, and leaves. Quantitative real-time PCR analyses revealed that the expression levels of representative GsPP2C and AtPP2C clade D genes were significantly influenced by alkali and salt stresses, suggesting that these genes might be associated with or directly involved in the relevant stress signaling pathways. Our results established a foundation for further functional characterization of PP2C clade D genes in the future.
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Affiliation(s)
- Chao Chen
- Key Laboratory of Agricultural Biological Functional Genes, Northeast Agricultural University, Harbin, 150030, People's Republic of China
| | - Yang Yu
- Key Laboratory of Agricultural Biological Functional Genes, Northeast Agricultural University, Harbin, 150030, People's Republic of China
| | - Xiaodong Ding
- Key Laboratory of Agricultural Biological Functional Genes, Northeast Agricultural University, Harbin, 150030, People's Republic of China
| | - Beidong Liu
- Department of chemistry and molecular biology, University of Gothenburg, S-413 90, Gothenburg, Sweden
| | - Huizi Duanmu
- Key Laboratory of Agricultural Biological Functional Genes, Northeast Agricultural University, Harbin, 150030, People's Republic of China
| | - Dan Zhu
- College of Life Science, Qingdao Agricultural University, Qingdao, People's Republic of China
| | - Xiaoli Sun
- Crop Stress Molecular Biology Laboratory, Heilongjiang Bayi Agricultural University, Daqing, People's Republic of China
| | - Lei Cao
- Key Laboratory of Agricultural Biological Functional Genes, Northeast Agricultural University, Harbin, 150030, People's Republic of China
| | - Zaib-Un-Nisa
- Key Laboratory of Agricultural Biological Functional Genes, Northeast Agricultural University, Harbin, 150030, People's Republic of China
| | - Qiang Li
- Key Laboratory of Agricultural Biological Functional Genes, Northeast Agricultural University, Harbin, 150030, People's Republic of China
| | - Yanming Zhu
- Key Laboratory of Agricultural Biological Functional Genes, Northeast Agricultural University, Harbin, 150030, People's Republic of China.
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8
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White-Gloria C, Johnson JJ, Marritt K, Kataya A, Vahab A, Moorhead GB. Protein Kinases and Phosphatases of the Plastid and Their Potential Role in Starch Metabolism. FRONTIERS IN PLANT SCIENCE 2018; 9:1032. [PMID: 30065742 PMCID: PMC6056723 DOI: 10.3389/fpls.2018.01032] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 06/25/2018] [Indexed: 05/03/2023]
Abstract
Phospho-proteomic studies have confirmed that phosphorylation is a common mechanism to regulate protein function in the chloroplast, including the enzymes of starch metabolism. In addition to the photosynthetic machinery protein kinases (STN7 and STN8) and their cognate protein phosphatases PPH1 (TAP38) and PBCP, multiple other protein kinases and phosphatases have now been localized to the chloroplast. Here, we build a framework for understanding protein kinases and phosphatases, their regulation, and potential roles in starch metabolism. We also catalog mapped phosphorylation sites on proteins of chloroplast starch metabolism to illustrate the potential and mostly unknown roles of protein phosphorylation in the regulation of starch biology.
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Affiliation(s)
- Chris White-Gloria
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Jayde J. Johnson
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Kayla Marritt
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Amr Kataya
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
- Department of Chemistry and Biosciences, University of Stavanger, Stavanger, Norway
| | - Ahmad Vahab
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Greg B. Moorhead
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
- *Correspondence: Greg B. Moorhead,
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9
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Comparison of two ELISA-based methods for the detection of microcystins in blood serum. Chem Biol Interact 2014; 223:10-7. [DOI: 10.1016/j.cbi.2014.08.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Revised: 08/26/2014] [Accepted: 08/29/2014] [Indexed: 11/24/2022]
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10
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Uhrig RG, Labandera AM, Moorhead GB. Arabidopsis PPP family of serine/threonine protein phosphatases: many targets but few engines. TRENDS IN PLANT SCIENCE 2013; 18:505-13. [PMID: 23790269 DOI: 10.1016/j.tplants.2013.05.004] [Citation(s) in RCA: 110] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 05/14/2013] [Accepted: 05/17/2013] [Indexed: 05/20/2023]
Abstract
The major plant serine/threonine protein phosphatases belong to the phosphoprotein phosphatase (PPP) family. Over the past few years the complement of Arabidopsis thaliana PPP family of catalytic subunits has been cataloged and many regulatory subunits identified. Specific roles for PPPs have been characterized, including roles in auxin and brassinosteroid signaling, in phototropism, in regulating the target of rapamycin pathway, and in cell stress responses. In this review, we provide a framework for understanding the PPP family by exploring the fundamental role of the phosphatase regulatory subunits that drive catalytic engine specificity. Although there are fewer plant protein phosphatases compared with their protein kinase partners, their function is now recognized to be as dynamic and as regulated as that of protein kinases.
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Affiliation(s)
- R Glen Uhrig
- Department of Biological Sciences, University of Calgary, Canada
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11
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Jia HF, Lu D, Sun JH, Li CL, Xing Y, Qin L, Shen YY. Type 2C protein phosphatase ABI1 is a negative regulator of strawberry fruit ripening. JOURNAL OF EXPERIMENTAL BOTANY 2013; 64:1677-87. [PMID: 23404898 PMCID: PMC3617833 DOI: 10.1093/jxb/ert028] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Although a great deal of progress has been made toward understanding the role of abscisic acid (ABA) in fruit ripening, many components in the ABA signalling pathway remain to be elucidated. Here, a strawberry gene homologous to the Arabidopsis gene ABI1, named FaABI1, was isolated and characterized. The 1641bp cDNA includes an intact open reading frame that encodes a deduced protein of 546 amino acids, in which putative conserved domains were determined by homology analysis. Transcriptional analysis showed that the levels of FaABI1 mRNA expression declined rapidly during strawberry fruit development as evidenced by real-time PCR, semi-quantitative reverse transcription-PCR, and northern blotting analyses, suggesting that the Ser/Thr protein phosphatase PP2C1 encoded by FaABI1 may be involved in fruit ripening as a negative regulator. The results of Tobacco rattle virus-induced gene silencing and PBI121 vector-mediated overexpression suggested that the down- and up-regulation of FaABI1 mRNA expression levels in degreening strawberry fruit could promote and inhibit ripening, respectively. Furthermore, alteration of FaABI1 expression could differentially regulate the transcripts of a set of both ABA-responsive and ripening-related genes, including ABI3, ABI4, ABI5, SnRK2, ABRE1, CHS, PG1, PL, CHI, F3H, DFR, ANS, and UFGT. Taken together, the data provide new evidence for an important role for ABA in regulating strawberry fruit ripening in the processes of which the type 2C protein phosphatase ABI1 serves as a negative regulator. Finally, a possible core mechanism underlying ABA perception and signalling transduction in strawberry fruit ripening is discussed.
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MESH Headings
- Abscisic Acid
- Agrobacterium/metabolism
- Base Sequence
- DNA, Complementary/genetics
- DNA, Complementary/metabolism
- Fragaria/enzymology
- Fragaria/genetics
- Fragaria/growth & development
- Fruit/enzymology
- Fruit/genetics
- Fruit/growth & development
- Gene Expression Profiling
- Gene Expression Regulation, Enzymologic
- Gene Expression Regulation, Plant
- Gene Silencing
- Genes, Plant
- Molecular Sequence Data
- Open Reading Frames
- Phosphoprotein Phosphatases/genetics
- Phosphoprotein Phosphatases/metabolism
- Plant Proteins/genetics
- Plant Proteins/metabolism
- Protein Phosphatase 2C
- RNA, Messenger/analysis
- RNA, Messenger/genetics
- RNA, Plant/analysis
- RNA, Plant/genetics
- Recombinant Proteins/genetics
- Recombinant Proteins/metabolism
- Signal Transduction
- Transcription, Genetic
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Affiliation(s)
- Hai-Feng Jia
- Beijing Key Laboratory of New Technology in Agricultural Application, College of Plant Science and Technology, Beijing University of Agriculture, No. 7 Beinong Road, Changping District, Beijing 102206, PR China
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12
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Antolín-Llovera M, Leivar P, Arró M, Ferrer A, Boronat A, Campos N. Modulation of plant HMG-CoA reductase by protein phosphatase 2A: positive and negative control at a key node of metabolism. PLANT SIGNALING & BEHAVIOR 2011; 6:1127-31. [PMID: 21701259 PMCID: PMC3260709 DOI: 10.4161/psb.6.8.16363] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The enzyme HMG-CoA reductase (HMGR) has a key regulatory role in the mevalonate pathway for isoprenoid biosynthesis, critical not only for normal plant development, but also for the adaptation to demanding environmental conditions. Consistent with this notion, plant HMGR is modulated by many diverse endogenous signals and external stimuli. Protein phosphatase 2A (PP2A) is involved in auxin, abscisic acid, ethylene and brassinosteroid signaling and now emerges as a positive and negative multilevel regulator of plant HMGR, both during normal growth and in response to a variety of stress conditions. The interaction with HMGR is mediated by B" regulatory subunits of PP2A, which are also calcium binding proteins. The new discoveries uncover the potential of PP2A to integrate developmental and calcium-mediated environmental signals in the control of plant HMGR.
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Affiliation(s)
- Meritxell Antolín-Llovera
- Department of Molecular Genetics; Center for Research in Agricultural Genomics (CSIC-IRTA-UAB-UB); Campus Universitat Autònoma de Barcelona; Bellaterra (Cerdanyola del Vallès); Barcelona, Spain
- Departament de Bioquímica i Biologia Molecular; Facultat de Biologia; Universitat de Barcelona; Barcelona, Spain
| | - Pablo Leivar
- Department of Molecular Genetics; Center for Research in Agricultural Genomics (CSIC-IRTA-UAB-UB); Campus Universitat Autònoma de Barcelona; Bellaterra (Cerdanyola del Vallès); Barcelona, Spain
- Departament de Bioquímica i Biologia Molecular; Facultat de Biologia; Universitat de Barcelona; Barcelona, Spain
| | - Montserrat Arró
- Department of Molecular Genetics; Center for Research in Agricultural Genomics (CSIC-IRTA-UAB-UB); Campus Universitat Autònoma de Barcelona; Bellaterra (Cerdanyola del Vallès); Barcelona, Spain
- Departament de Bioquímica i Biologia Molecular; Facultat de Farmàcia; Universitat de Barcelona; Barcelona, Spain
| | - Albert Ferrer
- Department of Molecular Genetics; Center for Research in Agricultural Genomics (CSIC-IRTA-UAB-UB); Campus Universitat Autònoma de Barcelona; Bellaterra (Cerdanyola del Vallès); Barcelona, Spain
- Departament de Bioquímica i Biologia Molecular; Facultat de Farmàcia; Universitat de Barcelona; Barcelona, Spain
| | - Albert Boronat
- Department of Molecular Genetics; Center for Research in Agricultural Genomics (CSIC-IRTA-UAB-UB); Campus Universitat Autònoma de Barcelona; Bellaterra (Cerdanyola del Vallès); Barcelona, Spain
- Departament de Bioquímica i Biologia Molecular; Facultat de Biologia; Universitat de Barcelona; Barcelona, Spain
| | - Narciso Campos
- Department of Molecular Genetics; Center for Research in Agricultural Genomics (CSIC-IRTA-UAB-UB); Campus Universitat Autònoma de Barcelona; Bellaterra (Cerdanyola del Vallès); Barcelona, Spain
- Departament de Bioquímica i Biologia Molecular; Facultat de Biologia; Universitat de Barcelona; Barcelona, Spain
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13
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Samofalova DA, Karpov PA, Nuporko AY, Blume YB. Reconstruction of the spatial structure of plant phosphatases types 1 and 2A in complexes with okadaic acid. CYTOL GENET+ 2011. [DOI: 10.3103/s0095452711030108] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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14
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Leivar P, Antolín-Llovera M, Ferrero S, Closa M, Arró M, Ferrer A, Boronat A, Campos N. Multilevel control of Arabidopsis 3-hydroxy-3-methylglutaryl coenzyme A reductase by protein phosphatase 2A. THE PLANT CELL 2011; 23:1494-511. [PMID: 21478440 PMCID: PMC3101556 DOI: 10.1105/tpc.110.074278] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2010] [Revised: 03/02/2011] [Accepted: 03/23/2011] [Indexed: 05/18/2023]
Abstract
Plants synthesize a myriad of isoprenoid products that are required both for essential constitutive processes and for adaptive responses to the environment. The enzyme 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) catalyzes a key regulatory step of the mevalonate pathway for isoprenoid biosynthesis and is modulated by many endogenous and external stimuli. In spite of that, no protein factor interacting with and regulating plant HMGR in vivo has been described so far. Here, we report the identification of two B'' regulatory subunits of protein phosphatase 2A (PP2A), designated B''α and B''β, that interact with HMGR1S and HMGR1L, the major isoforms of Arabidopsis thaliana HMGR. B''α and B''β are Ca²⁺ binding proteins of the EF-hand type. We show that HMGR transcript, protein, and activity levels are modulated by PP2A in Arabidopsis. When seedlings are transferred to salt-containing medium, B''α and PP2A mediate the decrease and subsequent increase of HMGR activity, which results from a steady rise of HMGR1-encoding transcript levels and an initial sharper reduction of HMGR protein level. In unchallenged plants, PP2A is a posttranslational negative regulator of HMGR activity with the participation of B''β. Our data indicate that PP2A exerts multilevel control on HMGR through the five-member B'' protein family during normal development and in response to a variety of stress conditions.
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Affiliation(s)
- Pablo Leivar
- Departament de Bioquímica i Biologia Molecular, Facultat de Biologia, Universitat de Barcelona, Barcelona 08028, Spain
| | - Meritxell Antolín-Llovera
- Departament de Bioquímica i Biologia Molecular, Facultat de Biologia, Universitat de Barcelona, Barcelona 08028, Spain
| | - Sergi Ferrero
- Departament de Bioquímica i Biologia Molecular, Facultat de Biologia, Universitat de Barcelona, Barcelona 08028, Spain
| | - Marta Closa
- Departament de Bioquímica i Biologia Molecular, Facultat de Farmàcia, Universitat de Barcelona, Barcelona 08028, Spain
| | - Montserrat Arró
- Departament de Bioquímica i Biologia Molecular, Facultat de Farmàcia, Universitat de Barcelona, Barcelona 08028, Spain
| | - Albert Ferrer
- Departament de Bioquímica i Biologia Molecular, Facultat de Farmàcia, Universitat de Barcelona, Barcelona 08028, Spain
| | - Albert Boronat
- Departament de Bioquímica i Biologia Molecular, Facultat de Biologia, Universitat de Barcelona, Barcelona 08028, Spain
| | - Narciso Campos
- Departament de Bioquímica i Biologia Molecular, Facultat de Biologia, Universitat de Barcelona, Barcelona 08028, Spain
- Address correspondence to
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15
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Gupta V, Roy A, Tripathy BC. Signaling events leading to red-light-induced suppression of photomorphogenesis in wheat (Triticum aestivum). PLANT & CELL PHYSIOLOGY 2010; 51:1788-1799. [PMID: 20823341 DOI: 10.1093/pcp/pcq139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Perception of red light (400 μmol photon m²/s) by the shoot bottom turned off the greening process in wheat. To understand the signaling cascade leading to this photomorphogenic response, certain signaling components were probed in seedlings grown in different light regimes. Upon analysis the gene expression of heterotrimeric Gα and Gβ were severely down-regulated in seedlings grown without vermiculite and having their shoot bottom exposed to red light (R/V-) and was similar to that of dark-grown seedlings. Supplementing the red-light-grown V- seedlings with blue light resulted in up-regulation of both Gα and Gβ expression, suggesting that blue light is able to modulate G protein expression. Treatment of cytokinin analog benzyladenine to cytokinin-deficient red-light-grown R/V- seedlings resulted in up-regulation of gene expression of both Gα and Gβ. To probe further, modulators of signal transduction pathway--AlF₃ (G protein activator), LaCl₃ (Ca(2+) channel blocker), NaF (nonspecific phosphatase inhibitor), or calmodulin (CaM) antagonists trifluoperazine (TFP) and N-(6-aminohexyl)-5-chloro-1-nafthalene-sulfonamide (W-7)--were added along with Hoagland solution to the roots of 4-day-old etiolated seedlings, grown on germination paper and transferred to red light. AlF₃, LaCl₃, NaF failed to elicit any photomorphogenic response. However, CaM antagonists TFP and W-7 significantly reversed the red-light-induced suppression of photomorphogenesis. Phosphorylation of proteins assayed in the absence or presence of CaM antagonist TFP revealed respective up-regulation or down-regulation of phosphorylation of several plastidic proteins in R/V- seedlings. These suggest that signal transduction of red light perceived by the shoot bottom to suppress photomorphogenesis is mediated by CaM-dependent protein kinases.
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Affiliation(s)
- Varsha Gupta
- School of Life Sciences, Jawaharlal Nehru University, New Delhi 110 067, India
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16
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Martinez-Noël GA, Tognetti JA, Salerno GL, Pontis HG. Sugar signaling of fructan metabolism: New insights on protein phosphatases in sucrose-fed wheat leaves. PLANT SIGNALING & BEHAVIOR 2010; 230:1071-9. [PMID: 20220311 DOI: 10.1007/s00425-009-1002-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2009] [Accepted: 08/05/2009] [Indexed: 05/21/2023]
Abstract
Protein phosphatase type 2A (PP2A) activity is required for the sucrose induction of fructan metabolism in wheat leaves, as shown in experiments with the addition of the specific inhibitor okadaic acid (OA) together with sucrose. However, a decrease in total PP2A activity has been found along sucrose treatment. Here we analyze the effect of sucrose feeding to wheat leaves on PP2A activity profiles after Deae-Sephacel and Superose separation, in comparison with those of control leaves. The results show no evidence of changes in PP2A activity profiles as a consequence of sucrose feeding. In all, our data suggest that constitutive levels of PP2A activity may be sufficient for the sucrose-mediated induction of fructan metabolism and that general decrease of PP2A activity produced by long-term treatment with sucrose may be due to a negative feedback regulation.
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17
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Matre P, Meyer C, Lillo C. Diversity in subcellular targeting of the PP2A B'eta subfamily members. PLANTA 2009; 230:935-45. [PMID: 19672620 DOI: 10.1007/s00425-009-0998-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2009] [Accepted: 07/22/2009] [Indexed: 05/20/2023]
Abstract
Protein phosphatase 2A (PP2A) is a serine/threonine-specific phosphatase comprising a catalytic subunit (C), a scaffolding subunit (A), and a regulatory subunit (B). The B subunits are believed to be responsible for substrate specificity and localization of the PP2A complex. In plants, three families of B subunits exist, i.e. B (B55), B', and B''. Here, we report differential subcellular targeting within the Arabidopsis B'eta subfamily, which consists of the close homologs B'eta, B'theta, B'gamma and B'zeta. Phenotypes of corresponding knockouts were observed, and particularly revealed delayed flowering for the B'eta knockout. The B' subunits were linked to fluorescent tags and transiently expressed in various tissues of onion, tobacco and Arabidopsis. B'eta and B'gamma targeted the cytosol and nucleus. B'zeta localized to the cytoplasm and partly co-localized with mitochondrial markers when the N-terminus was free. Provided its C-terminus was free, the B'theta subunit targeted peroxisomes. The importance of the C-terminal end for peroxisomal targeting was further confirmed by truncation of the C-terminus. The results revealed that the closely related B' subunits are targeting different organelles in plants, and exemplify the usage of the peptide serine-serine-leucine as a PTS1 peroxisomal signaling peptide.
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Affiliation(s)
- Polina Matre
- Faculty of Science and Technology, University of Stavanger, Centre for Organelle Research, 4036 Stavanger, Norway
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18
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Jan G, Delorme V, Saksouk N, Abrivard M, Gonzalez V, Cayla X, Hakimi MA, Tardieux I. A Toxoplasma type 2C serine-threonine phosphatase is involved in parasite growth in the mammalian host cell. Microbes Infect 2009; 11:935-45. [PMID: 19563907 DOI: 10.1016/j.micinf.2009.06.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2009] [Revised: 06/09/2009] [Accepted: 06/16/2009] [Indexed: 01/03/2023]
Abstract
Toxoplasma gondii is a human protozoan parasite that belongs to the phylum of Apicomplexa and causes toxoplasmosis. As the other members of this phylum, T. gondii obligatory multiplies within a host cell by a peculiar type of mitosis that leads to daughter cell assembly within a mother cell. Although parasite growth and virulence have been linked for years, few molecules controlling mitosis have been yet identified and they include a couple of kinases but not the counteracting phosphatases. Here, we report that in contrast to other animal cells, type 2C is by far the major type of serine threonine phosphatase activity both in extracellular and in intracellular dividing parasites. Using wild type and transgenic parasites, we characterized the 37kDa TgPP2C molecule as an abundant cytoplasmic and nuclear enzyme with activity being under tight regulation. In addition, we showed that the increase in TgPP2C activity significantly affected parasite growth by impairing cytokinesis while nuclear division still occurred. This study supports for the first time that type 2C protein phosphatase is an important regulator of cell growth in T. gondii.
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Affiliation(s)
- Gaelle Jan
- Institut Cochin, Université Paris Descartes, CNRS UMR 8104, Paris, France
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19
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Takemiya A, Ariyoshi C, Shimazaki KI. Identification and functional characterization of inhibitor-3, a regulatory subunit of protein phosphatase 1 in plants. PLANT PHYSIOLOGY 2009; 150:144-56. [PMID: 19329567 PMCID: PMC2675749 DOI: 10.1104/pp.109.135335] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2009] [Accepted: 03/24/2009] [Indexed: 05/23/2023]
Abstract
Protein phosphatase 1 (PP1) is a eukaryotic serine/threonine protein phosphatase, and mediates diverse cellular processes in animal systems via the association of a catalytic subunit (PP1c) with multiple regulatory subunits that determine the catalytic activity, the subcellular localization, and the substrate specificity. However, no regulatory subunit of PP1 has been identified in plants so far. In this study, we identified inhibitor-3 (Inh3) as a regulatory subunit of PP1 and characterized a functional role of Inh3 in Vicia faba and Arabidopsis (Arabidopsis thaliana). We found Inh3 as one of the proteins interacting with PP1c using a yeast two-hybrid system. Biochemical analyses demonstrated that Arabidopsis Inh3 (AtInh3) bound to PP1c via the RVxF motif of AtInh3, a consensus PP1c-binding sequence both in vitro and in vivo. AtInh3 inhibited the PP1c phosphatase activity in the nanomolar range in vitro. AtInh3 was localized in both the nucleus and cytoplasm, and it colocalized with Arabidopsis PP1c in these compartments. Disruption mutants of AtINH3 delayed the progression of early embryogenesis, arrested embryo development at the globular stage, and eventually caused embryo lethality. Furthermore, reduction of AtINH3 expression by RNA interference led to a decrease in fertility. Transformation of the lethal mutant of inh3 with wild-type AtINH3 restored the phenotype, whereas that with the AtINH3 gene having a mutation in the RVxF motif did not. These results define Inh3 as a regulatory subunit of PP1 in plants and suggest that Inh3 plays a crucial role in early embryogenesis in Arabidopsis.
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Affiliation(s)
- Atsushi Takemiya
- Department of Biology, Faculty of Science, Kyushu University, Hakozaki, Fukuoka 812-8581, Japan
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20
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Yu RMK, Wong MML, Jack RW, Kong RYC. Structure, evolution and expression of a second subfamily of protein phosphatase 2A catalytic subunit genes in the rice plant (Oryza sativa L.). PLANTA 2005; 222:757-68. [PMID: 16021503 DOI: 10.1007/s00425-005-0018-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2005] [Accepted: 04/28/2005] [Indexed: 05/03/2023]
Abstract
Protein phosphatase 2A (PP2A) is one of the major serine/threonine protein phosphatases in the cell and plays a variety of regulatory roles in metabolism and signal transduction. Previously, we described the structure and expression of two genes encoding PP2A catalytic subunits (PP2Ac)--OsPP2A-1 and OsPP2A-3--in the rice plant (Yu et al. 2003). Here, we report the isolation and characterisation of a second structurally distinguishable PP2Ac subfamily comprised of three additional isogenes, OsPP2A-2, OsPP2A-4 (each containing ten introns) and OsPP2A-5 (which contains nine introns). Northern blot analysis demonstrated that the three isogenes are ubiquitously expressed in all rice tissues during plant development, and differentially expressed in response to high salinity and the combined stresses of drought and heat. Phylogenetic analyses indicated that the two PP2Ac subfamilies are descended from two ancient lineages, which derived from gene duplications that occurred after the monocotyledon-dicotyledon split. In the second subfamily, it is proposed that two duplication events were involved; in which, the initial duplication of a ten-intron primordial gene yielded OsPP2A-2 and the progenitor of OsPP2A-4 and OsPP2A-5. The OsPP2A-4/OsPP2A-5 progenitor, in turn, underwent a second duplication event, resulting in the present day OsPP2A-4 and OsPP2A-5. It is proposed that loss of the 5'-most intron from OsPP2A-5 occurred after these two duplication events.
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Affiliation(s)
- Richard Man Kit Yu
- Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong
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21
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Tao Y, Rao PK, Bhattacharjee S, Gelvin SB. Expression of plant protein phosphatase 2C interferes with nuclear import of the Agrobacterium T-complex protein VirD2. Proc Natl Acad Sci U S A 2004; 101:5164-9. [PMID: 15047887 PMCID: PMC387391 DOI: 10.1073/pnas.0300084101] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Agrobacterium tumefaciens transfers DNA to plant cells as a single-stranded DNA molecule (the T-strand) covalently linked to VirD2 protein. VirD2 contains nuclear localization signal sequences that presumably help direct the T-strand to the plant nucleus. We identified a tomato cDNA clone, DIG3, that encodes a protein that interacts with the C-terminal region of VirD2. DIG3 encodes an enzymatically active type 2C serine/threonine protein phosphatase. Overexpression of DIG3 in tobacco BY-2 protoplasts inhibited nuclear import of a beta-glucuronidase-VirD2 nuclear localization signal fusion protein. Thus, DIG3 may be involved in nuclear import of the VirD2 protein and, consequently, the VirD2/transferred DNA complex.
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Affiliation(s)
- Yumin Tao
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
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22
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Chen J, Song L, Dai J, Gan N, Liu Z. Effects of microcystins on the growth and the activity of superoxide dismutase and peroxidase of rape (Brassica napus L.) and rice (Oryza sativa L.). Toxicon 2004; 43:393-400. [PMID: 15051402 DOI: 10.1016/j.toxicon.2004.01.011] [Citation(s) in RCA: 147] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2003] [Revised: 01/17/2004] [Accepted: 01/20/2004] [Indexed: 11/17/2022]
Abstract
Microcystins are naturally occurring hepatotoxic cyclic heptapeptides produced by some toxic freshwater cyanobacterial species. In this study, crude extract of toxic cyanobacterial blooms from Dianchi Lake in southwestern China was used to determine the effects of microcystins on rape (Brassica napus L.) and rice (Oryza sativa L.). Experiments were carried out on a range of doses of the extract (equivalent to 0, 0.024, 0.12, 0.6 and 3 microg MC-LR/ml). Investigations showed that exposure to microcystins inhibited the growth and development of both rice and rape seedlings, however, microcystins had more powerful inhibition effect on rape than rice in germination percentage of seeds and seedling height. Microcystins significantly inhibited the elongation of primary roots of rape and rice seedlings. Determination of the activities of peroxidase and superoxide dismutase demonstrated that microcystin stress was manifested as an oxidative stress. Using ELISA, microcystins were examined from the extract of exposed rape and rice seedlings, indicating that consumption of edible plants exposed to microcystins via irrigation route may have health risks. Significantly different levels of recovered microcystins between exposed rice and rape seedlings suggested that there might be different tolerant mechanisms toward microcystins.
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Affiliation(s)
- Jianzhong Chen
- Department of Biology, School of Life Sciences, Nanjing University, Nanjing 210093, China
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23
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Yu RMK, Zhou Y, Xu ZF, Chye ML, Kong RYC. Two genes encoding protein phosphatase 2A catalytic subunits are differentially expressed in rice. PLANT MOLECULAR BIOLOGY 2003; 51:295-311. [PMID: 12602862 DOI: 10.1023/a:1022006023273] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Type 2A serine/threonine protein phosphatase (PP2A) plays a variety of regulatory roles in metabolism and signal transduction. Two closely related PP2A catalytic subunit (PP2Ac) genes, OsPP2A-1 and OsPP2A-3, have been isolated from the monocot Oryza sativa. Both genes contain six exons and five introns which intervene at identical locations, suggesting they have descended from a recent duplication event. Their encoded proteins share 97% sequence identity and are highly similar (94-96%) to a PP2Ac subfamily (AtPP2A-1, -2 and -5) identified in Arabidopsis thaliana. Both OsPP2A-1 and OsPP2A-3 are ubiquitously expressed, with the expression levels high in stems and flowers and low in leaves. OsPP2A-1, but not OsPP2A-3, is also highly expressed in roots. Transcript levels of OsPP2A-1 in roots and OsPP2A-3 in stems are elevated at the maturation and young stages, respectively. Drought and high salinity upregulate both genes in leaves, whereas heat stress represses OsPP2A-1 in stems and induces OsPP2A-3 in all organs. These findings indicate that the two PP2Ac genes are subjected to developmental and stress-related regulation. In situ hybridization results show that both transcripts exhibit nearly identical cellular distribution, except in leaves, and are abundant in meristematic tissues including the young leaf blade of stems and the root tip.
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MESH Headings
- Amino Acid Sequence
- Base Sequence
- Blotting, Northern
- Catalytic Domain/genetics
- DNA, Plant/chemistry
- DNA, Plant/genetics
- DNA, Plant/isolation & purification
- Exons
- Gene Expression Regulation, Developmental
- Gene Expression Regulation, Enzymologic
- Gene Expression Regulation, Plant
- Genes, Plant/genetics
- In Situ Hybridization
- Introns
- Isoenzymes/genetics
- Molecular Sequence Data
- Oryza/enzymology
- Oryza/genetics
- Oryza/growth & development
- Phosphoprotein Phosphatases/genetics
- Promoter Regions, Genetic/genetics
- Protein Phosphatase 2
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
- Transcription Initiation Site
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Affiliation(s)
- Richard Man Kit Yu
- Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong Special Administrative Region, People's Republic of China
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24
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Abstract
Phosphorylation and dephosphorylation of a protein often serve as an "on-and-off" switch in the regulation of cellular activities. Recent studies demonstrate the involvement of protein phosphorylation in almost all signaling pathways in plants. A significant portion of the sequenced Arabidopsis genome encodes protein kinases and protein phosphatases that catalyze reversible phosphorylation. For optimal regulation, kinases and phosphatases must strike a balance in any given cell. Only a very small fraction of the thousands of protein kinases and phosphatases in plants has been studied experimentally. Nevertheless, the available results have demonstrated critical functions for these enzymes in plant growth and development. While serine/threonine phosphorylation is widely accepted as a predominant modification of plant proteins, the function of tyrosine phosphorylation, desptie its overwhelming importance in animal systems, had been largely neglected until recently when tyrosine phosphatases (PTPs) were characterized from plants. This review focuses on the structure, regulation, and function of protein phosphatases in higher plants.
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Affiliation(s)
- Sheng Luan
- Department of Plant and Microbial Biology, University of California at Berkeley, Berkeley, California 94720, USA.
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25
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Stubbs MD, Tran HT, Atwell AJ, Smith CS, Olson D, Moorhead GB. Purification and properties of Arabidopsis thaliana type 1 protein phosphatase (PP1). BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1550:52-63. [PMID: 11738087 DOI: 10.1016/s0167-4838(01)00267-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The Arabidopsis thaliana type 1 protein phosphatase (PP1) catalytic subunit was released from its endogenous regulatory subunits by ethanol precipitation and purified by anion exchange and microcystin affinity chromatography. The enzyme was identified by MALDI-TOF mass spectrometry from a tryptic digest of the purified protein as a mixture of PP1 isoforms (TOPP 1-6) indicating that at least 4-6 of the eight known PP1 proteins are expressed in sufficient quantities for purification from A. thaliana suspension cells. The enzyme had a final specific activity of 8950 mU/mg using glycogen phosphorylase a as substrate, had a subunit molecular mass of 35 kDa as determined by SDS-PAGE and behaved as a monomeric protein of approx. 39 kDa on Superose 12 gel filtration chromatography. Similar to the mammalian type 1 protein phosphatases, the A. thaliana enzyme was potently inhibited by Inhibitor-2 (IC(50)=0.65 nM), tautomycin (IC(50)=0.06 nM), microcystin-LR (IC(50)=0.01 nM), nodularin (IC(50)=0.035 nM), calyculin A (IC(50)=0.09 nM), okadaic acid (IC(50)=20 nM) and cantharidin (IC(50)=60 nM). The enzyme was also inhibited by fostriecin (IC(50)=22 microM), NaF (IC(50)=2.1 mM), Pi (IC(50)=9.5 mM), and PPi (IC(50)=0.07 mM). Purification of the free catalytic subunit allowed it to be used to probe protein phosphatase holoenzyme complexes that were enriched on Q-Sepharose and a microcystin-Sepharose affinity matrix and confirmed several proteins to be PP1 targeting subunits.
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Affiliation(s)
- M D Stubbs
- Department of Biological Sciences, University of Calgary, AB, Canada
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26
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McElhiney J, Lawton LA, Leifert C. Investigations into the inhibitory effects of microcystins on plant growth, and the toxicity of plant tissues following exposure. Toxicon 2001; 39:1411-20. [PMID: 11384731 DOI: 10.1016/s0041-0101(01)00100-3] [Citation(s) in RCA: 134] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The cyanobacterial toxins microcystins are known to affect a number of processes in plant tissues, and their presence in water used for irrigation may have considerable impact on the growth and development of crop plants. In this study, two plant bioassays were employed to investigate the phytotoxic effects of microcystins. A plant tissue culture assay revealed that the growth and chlorophyll content of Solanum tuberosum L. cultures was inhibited at microcystin-LR concentrations of 0.005 and 0.05 microg x cm(-3), respectively. A previously developed bioassay was also employed to determine the effects of three commonly occurring microcystin variants on the growth of Synapis alba L. seedlings. Microcystins-LR, -RR, and -LF inhibited the growth of seedlings, with GI50 values of 1.9, 1.6 and 7.7 microg x ml(-1), respectively. The growth of Phaseolus vulgaris was also examined in the presence of microcystin-LR. The toxin was found to have little effect on growth for up to 18 days, but impaired the development of the roots of exposed plants, causing them to take up approximately 30% less growth medium than those grown in the absence of toxin. Microcystin was also detected in the tissues of exposed plants using a commercially available ELISA kit, suggesting that the uptake of these toxins by edible plants may have significant implications for human health.
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Affiliation(s)
- J McElhiney
- The Robert Gordon University, School of Applied Sciences, St. Andrew Street, AB25 1HG, Aberdeen, UK
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27
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Merlot S, Gosti F, Guerrier D, Vavasseur A, Giraudat J. The ABI1 and ABI2 protein phosphatases 2C act in a negative feedback regulatory loop of the abscisic acid signalling pathway. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2001; 25:295-303. [PMID: 11208021 DOI: 10.1046/j.1365-313x.2001.00965.x] [Citation(s) in RCA: 400] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
The Arabidopsis ABI1 and ABI2 genes encode two protein serine/threonine phosphatases 2C (PP2C). These genes have been originally identified by the dominant mutations abi1--1 and abi2--1, which reduce the plant's responsiveness to the hormone abscisic acid (ABA). However, recessive mutants of ABI1 were recently shown to be supersensitive to ABA, which demonstrated that the ABI1 phosphatase is a negative regulator of ABA signalling. We report here the isolation and characterisation of the first reduction-of-function allele of ABI2, abi2--1R1. The in vitro phosphatase activity of the abi2--1R1 protein is approximately 100-fold lower than that of the wild-type ABI2 protein. Abi2--1R1 plants displayed a wild-type ABA sensitivity. However, doubly mutant plants combining the abi2--1R1 allele and a loss-of-function allele at the ABI1 locus were more responsive to ABA than each of the parental single mutants. These data indicate that the wild-type ABI2 phosphatase is a negative regulator of ABA signalling, and that the ABI1 and ABI2 phosphatases have overlapping roles in controlling ABA action. Measurements of PP2C activity in plant extracts showed that the phosphatase activity of ABI1 and ABI2 increases in response to ABA. These results suggest that ABI1 and ABI2 act in a negative feedback regulatory loop of the ABA signalling pathway.
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Affiliation(s)
- S Merlot
- Institut des Sciences Végétales, Centre National de la Recherche Scientifique UPR 40, Avenue de la Terrasse, 91190 Gif-sur-Yvette, France
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28
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Pujol G, Baskin TI, Casamayor A, Cortadellas N, Ferrer A, Ariño J. The Arabidopsis thaliana PPX/PP4 phosphatases: molecular cloning and structural organization of the genes and immunolocalization of the proteins to plastids. PLANT MOLECULAR BIOLOGY 2000; 44:499-511. [PMID: 11197325 DOI: 10.1023/a:1026587405656] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The PPX/PP4 Ser/Thr protein phosphatases belong to the type 2A phosphatase subfamily and are present in most eukaryotic organisms. We have previously isolated two closely related DNAs encoding PPX isoforms (PPX-1 and PPX-2) of Arabidopsis thaliana. Here we report the molecular cloning of the genes encoding these proteins. The genes PPX-1 and PPX-2 are composed of eight exons and seven introns located at equivalent positions related to the coding sequences. Whereas the intron-exon organization of the PPX genes is completely different from that of the PP2A-3/PP2A-4 A. thaliana family, specific intron-exon boundaries are conserved among PPX genes from distantly related organisms. Based on GUS expression, both PPX genes show the same spatial and temporal pattern of expression: they are expressed in all the organs and tissues analyzed, and from the earliest stage of development. When PPX proteins were localized to the root in semi-thin methacrylate sections by immunofluorescence, staining was predominantly confined to small organelles, shown to be plastids by co-localization of PPX and ferredoxin. Interestingly, only some ferredoxin-positive plastids were also PPX-positive, and PPX staining was consistently brighter in the epidermis. The localization was confirmed with immunogold and electron microscopy. Our results suggest that, despite its strong sequence conservation, PPX in plants functions differently than in animals.
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MESH Headings
- Arabidopsis/enzymology
- Arabidopsis/genetics
- Arabidopsis/ultrastructure
- Cloning, Molecular
- DNA, Plant/chemistry
- DNA, Plant/genetics
- Exons
- Gene Expression Regulation, Enzymologic
- Gene Expression Regulation, Plant
- Genes, Plant/genetics
- Glucuronidase/genetics
- Glucuronidase/metabolism
- Introns
- Isoenzymes/genetics
- Microscopy, Immunoelectron
- Molecular Sequence Data
- Phosphoprotein Phosphatases/genetics
- Plants, Genetically Modified/enzymology
- Plants, Genetically Modified/genetics
- Plants, Genetically Modified/growth & development
- Plastids/enzymology
- Plastids/ultrastructure
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Recombinant Fusion Proteins/genetics
- Recombinant Fusion Proteins/metabolism
- Sequence Analysis, DNA
- Tissue Distribution
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Affiliation(s)
- G Pujol
- Dept. de Bioquímica i Biologia Molecular, Facultat dle Farmàcia, Universitat de Barcelona, Spain
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29
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Awotunde OS, Sugajska E, Zolnierowicz S, Muszyńska G. Characterisation of two protein phosphatase 2A holoenzymes from maize seedlings. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1480:65-76. [PMID: 11004556 DOI: 10.1016/s0167-4838(00)00097-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Two holoenzymes of protein phosphatase 2A (PP2A), designated PP2AI and PP2AII, were purified from maize seedlings. The subunit composition of maize holoenzymes generally resembled those of animal PP2A. Using SDS/PAGE and Western blots with antibodies generated against peptides derived from animal PP2A, we established the subunit composition of plant protein phosphatase 2A. In both maize holoenzymes, a 38000 catalytic (PP2Ac) and a 66000 constant regulatory subunit (A) constituting the core dimer of PP2A were present. In addition, PP2AI (180000-200000) contained a protein of 57000 which reacted with antibodies generated against the peptide (EFDYLKSLEIEE) conserved in all eukaryotic Balpha regulatory subunits. In contrast, none of the proteins visualised in PP2AII (140000-160000) by double staining reacted with these antibodies. The activity of PP2AI measured with (32)P-labelled phosphorylase a in the presence of protamine and ammonium sulfate is about two times higher than that of PP2AII. PP2AI and PP2AII displayed different patterns of activation by protamine, polylysine and histone H1 and exhibit high sensitivity toward inhibition by okadaic acid. The data obtained provide direct biochemical evidence for the existence in plants of PP2A holoenzymes composed of a catalytic subunit complexed with one or two regulatory subunits.
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Affiliation(s)
- O S Awotunde
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
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30
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Riou-Khamlichi C, Menges M, Healy JM, Murray JA. Sugar control of the plant cell cycle: differential regulation of Arabidopsis D-type cyclin gene expression. Mol Cell Biol 2000; 20:4513-21. [PMID: 10848578 PMCID: PMC85832 DOI: 10.1128/mcb.20.13.4513-4521.2000] [Citation(s) in RCA: 267] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
In most plants, sucrose is the major transported carbon source. Carbon source availability in the form of sucrose is likely to be a major determinant of cell division, and mechanisms must exist for sensing sugar levels and mediating appropriate control of the cell cycle. We show that sugar availability plays a major role during the G(1) phase by controlling the expression of CycD cyclins in Arabidopsis. CycD2 mRNA levels increase within 30 min of the addition of sucrose; CycD3 is induced after 4 h. This corresponds to induction of CycD2 expression early in G(1) and CycD3 expression in late G(1) near the S-phase boundary. CycD2 and CycD3 induction is independent both of progression to a specific point in the cell cycle and of protein synthesis. Protein kinase activity of CycD2- and CycD3-containing cyclin-dependent kinases is consistent with the observed regulation of their mRNA levels. CycD2 and CycD3 therefore act as direct mediators of the presence of sugar in cell cycle commitment. CycD3, but not CycD2, expression responds to hormones, for which we show that the presence of sugars is required. Finally, protein phosphatases are shown to be involved in regulating CycD2 and CycD3 induction. We propose that control of CycD2 and CycD3 by sucrose forms part of cell cycle control in response to cellular carbohydrate status.
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Affiliation(s)
- C Riou-Khamlichi
- Institute of Biotechnology, University of Cambridge, United Kingdom
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31
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Kovacheva S, Ryberg M, Sundqvist C. ADP/ATP and protein phosphorylation dependence of phototransformable protochlorophyllide in isolated etioplast membranes. PHOTOSYNTHESIS RESEARCH 2000; 64:127-36. [PMID: 16228451 DOI: 10.1023/a:1006451824312] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The effects of modulated ADP/ATP and NADPH/NADP(+) ratios, and of protein kinase inhibitors, on the in vitro reformation of phototransformable protochlorophyllide, i.e. the aggregated ternary complexes between NADPH, protochlorophyllide, and NADPH-protochlorophyllide oxidoreductase (POR, EC 1.3.1.33), in etioplast membranes isolated from dark-grown wheat (Triticum aestivum) were investigated. Low temperature fluorescence emission spectra (-196 degrees C) were used to determine the state of the pigments. The presence of spectral intermediates of protochlorophyllide and the reformation of phototransformable protochlorophyllide were reduced at high ATP, but favoured by high ADP. Increased ADP level partly prevented the chlorophyllide blue-shift. The protein kinase inhibitor K252a prevented reformation of phototransformable protochlorophyllide without showing any effect on the chlorophyllide blue-shift. Addition of NADPH did not overcome the inhibition. The results indicate that protein phosphorylation plays a role in the conversion of the non-phototransformable protochlorophyllide to POR-associated phototransformable protochlorophyllide. The possible presence of a plastid ADP-dependent kinase, the activity of which favours the formation of PLBs, is discussed. Reversible protein phosphorylation is suggested as a regulatory mechanism in the prolamellar body formation and its light-dependent dispersal by affecting the membrane association of POR. By the presence of a high concentration of phototransformable protochlorophyllide, prolamellar bodies can act as light sensors for plastid development. The modulation of plastid protein kinase and protein phosphatase activities by the NADPH/NADP(+) ratio is suggested.
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Affiliation(s)
- S Kovacheva
- Botanical Institute, Department of Plant Physiology, Göteborg University, Box 461, SE 405 30, Göteborg, Sweden
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32
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Vener AV, Rokka A, Fulgosi H, Andersson B, Herrmann RG. A cyclophilin-regulated PP2A-like protein phosphatase in thylakoid membranes of plant chloroplasts. Biochemistry 1999; 38:14955-65. [PMID: 10555977 DOI: 10.1021/bi990971v] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Dephosphorylation of central photosynthetic proteins regulates their turnover in plant thylakoid membranes. A membrane protein phosphatase from spinach thylakoids was purified 13000-fold using detergent-engaged FPLC. The purified enzyme exhibited characteristics typical of eukaryotic Ser/Thr phosphatases of the PP2A family in that it was inhibited by okadaic acid (IC(50) = 0.4 nM) and tautomycin (IC(50) = 25 nM), irreversibly bound to microcystin-agarose, and recognized by a polyclonal antibody raised against a recombinant catalytic subunit of human PP2A. Furthermore, the anti-PP2A antibody inhibited protein dephosphorylation in isolated thylakoids. The phosphatase copurified with TLP40, a cyclophilin-like peptidyl-prolyl isomerase located in the thylakoid lumen. TLP40 could be released from the phosphatase immobilized on microcystin-agarose by high-salt treatment. Binding of cyclosporin A (CsA) to TLP40 led to thylakoid phosphatase activation, while cyclophilin substrates, prolyl-containing oligopeptides, inhibited protein dephosphorylation. This dephosphorylation could be modulated by CsA or oligopeptides only after the thylakoids had been ruptured to expose the lumenal membrane surface where the TLP40 is located. Regulation of the PP2A-like phosphatase at the outer thylakoid surface is likely to operate via reversible binding of TLP40 to the inner membrane surface. This is a first example of transmembrane regulation in which the activity of phosphatase is altered by the binding of a cyclophilin to a site other than the active one. We propose that signaling from TLP40 to the protein phosphatase coordinates dephosphorylation and protein folding, two processes required for protein turnover during the repair of photoinhibited photosystem II reaction centers.
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Affiliation(s)
- A V Vener
- Department of Biochemistry, Arrhenius Laboratories for Natural Sciences, Stockholm University, S-106 91 Stockholm, Sweden
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33
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Lin Q, Buckler ES, Muse SV, Walker JC. Molecular evolution of type 1 serine/threonine protein phosphatases. Mol Phylogenet Evol 1999; 12:57-66. [PMID: 10222161 DOI: 10.1006/mpev.1998.0560] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Type 1 serine/threonine protein phosphatases (PP1s) play key roles in many cellular processes. To understand the evolutionary relationships among PP1s from various kingdoms and to provide a valid basis to evaluate the structure-function relationships of these phosphatases, 44 PP1 sequences were aligned, revealing a high sequence similarity among PP1 homologs. About one-third of the total amino acids are conserved in all the sequences studied. Most of these conserved amino acids are located within a 270-amino-acid core region. They include most sites critical to the activity and regulation of PP1s based on three-dimensional structural studies of mammalian PP1s. Positional variation analysis using a sliding window approach revealed two variable blocks in the 270-amino-acid core region. The major variable block corresponds to a subdomain composed of three alpha-helices (alphaG, alphaH, and alphaI) and three beta-sheets (beta7, beta8, and beta9). Phylogenetic analyses suggested that plant and animal PP1s form distinct monophyletic groups. The plant PP1 family contains several subgroups that may be older than the monocot-dicot divergence. In the animal PP1 family, different vertebrate isoforms appear to form distinct subgroups. Relative substitution rate studies indicated that plant PP1s are more diverse than animal PP1s, with an average substitution rate 1.5 times as large as that of animal PP1s. The possible involvement of PP1s in the establishment of multicellularity is discussed.
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Affiliation(s)
- Q Lin
- Division of Biological Sciences, University of Missouri-Columbia, Columbia, Missouri, 65211, USA
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34
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Chang M, Wang B, Chen X, Wu R. Molecular characterization of catalytic-subunit cDNA sequences encoding protein phosphatases 1 and 2A and study of their roles in the gibberellin-dependent Osamy-c expression in rice. PLANT MOLECULAR BIOLOGY 1999; 39:105-115. [PMID: 10080713 DOI: 10.1023/a:1006152223183] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
To understand the molecular mechanism of gibberellin-dependent gene regulation, the effect of three phosphatase inhibitors on the germination of rice seeds and the expression of a target gene, the alpha-amylase gene, Osamy-c, were measured. We found that okadaic acid, microcystin-LR, and calyculin A, which are known to specifically inhibit Ser/Thr phosphatases 1 and 2A, strongly inhibit the expression of the Osamy-c and may be involved in the germination of rice seeds. The protein phosphatase enzyme activity assays showed that there is no obvious effect of GA3 on total PP1/PP2A activities. To further understand the possible role of protein phosphatases 1 and 2A in the GA-dependent expression of Osamy-c, we isolated cDNA clones encoding protein phosphatase 1 and protein phosphatase 2A from a rice aleurone cDNA library. These were designated OsPP1c and OsPP2Ac, respectively. Comparison of the deduced amino acid sequences of OsPP1c and OsPP2Ac with the catalytic subunits of PP1 or PP2A of rabbit skeletal muscle, Arabidopsis thaliana, maize and Brassica napus showed that the catalytic subunit sequences of PP1 or PP2A among these organisms are highly conserved (73% to 90% similarity). Genomic Southern blot analysis indicated that there are only one or two copies of OsPP1c genes and more than two copies of OsPP2Ac genes in the rice genome. Northern blot analysis showed that OsPP1c and OsPP2Ac genes are expressed in several organs of rice, including seed, shoot and root. We also showed by using 3' gene-specific probes of OsPP1c and OsPP2Ac cDNA, that the expression of neither gene is regulated by GA. Taken together, our results suggest that protein phosphatases PP1 or PP2A are involved in the GA-dependent expression of the rice Osamy-c gene, though the PP1 or/and PP2A enzymatic activities as well as mRNA levels do not increase upon GA3 treatment.
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Affiliation(s)
- M Chang
- Department of Plant Biology, Cornell University, Ithaca, NY 14853, USA
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35
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Kurki-Helasmo K, Meriluoto J. Microcystin uptake inhibits growth and protein phosphatase activity in mustard (Sinapis alba L.) seedlings. Toxicon 1998; 36:1921-6. [PMID: 9839676 DOI: 10.1016/s0041-0101(98)00114-7] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Mustard (Sinapis alba L.) seeds were cultivated for seven days on a solid nutrient medium supplemented with 040 microg microcystin-RR per ml. Microcystin-RR affected seedling growth (IC50 0.8 microg/ml) and microcystin concentrations > or =5.0 microg/ml produced malformed plants. The inhibition of protein phosphatase 1 and 2A activity correlated with the growth inhibition. The seedlings were also shown to take up 3H-dihydromicrocystin-LR derived radioactivity up to a level corresponding to ca. 80 ng toxin per mg plant protein.
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Affiliation(s)
- K Kurki-Helasmo
- Department of Biochemistry and Pharmacy, Abo Akademi University, Turku, Finland
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36
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Lin Q, Li J, Smith RD, Walker JC. Molecular cloning and chromosomal mapping of type one serine/threonine protein phosphatases in Arabidopsis thaliana. PLANT MOLECULAR BIOLOGY 1998; 37:471-481. [PMID: 9617814 DOI: 10.1023/a:1005912413555] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Type one serine/threonine protein phosphatases (PP1s) have been implicated in various processes of plant growth and development. In all plant species studied, PP1s are encoded by multigene families. Previous studies in our laboratory identified five Arabidopsis thaliana PP1 genes (TOPP1, TOPP2, TOPP3, TOPP4 and TOPP5). In the present study, we report the isolation of three additional PP1 genes (TOPP6, TOPP7 and TOPP8). Southern blot analyses indicate that these three newly isolated genes are single-copy genes in A. thaliana genome. All the three genes are expressed in roots, rosettes and flowers, although their expression levels appear to be lower than those of the five previously identified TOPP genes. Six of the eight TOPP genes were mapped to different positions on four of five A. thaliana chromosomes. Sequence comparison revealed that TOPP genes belong to different subgroups of plant PP1 genes, suggesting that they may encode proteins with distinct functions.
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Affiliation(s)
- Q Lin
- Division of Biological Sciences, University of Missouri-Columbia, 65211, USA
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37
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Kim CY, Gal SW, Choe MS, Jeong SY, Lee SI, Cheong YH, Lee SH, Choi YJ, Han CD, Kang KY, Cho MJ. A new class II rice chitinase, Rcht2, whose induction by fungal elicitor is abolished by protein phosphatase 1 and 2A inhibitor. PLANT MOLECULAR BIOLOGY 1998; 37:523-534. [PMID: 9617819 DOI: 10.1023/a:1005960313459] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Among the four classes of chitinase, a class II chitinase had not yet been reported for rice. We have isolated and characterized a class II acidic chitinase, Rcht2, from rice (Oryza sativa L. cv. Cheongcheongbyeo). The protein consists of a single polypeptide chain of 261 amino acid residues and includes a putative signal sequence of 29 amino acids at its N-terminus. It has a calculated molecular mass of 27,642 Da and an isoelectric point of 5.56. The Rcht2 chitinase lacks the cysteine-rich and hinge domains in the N-terminal region of the protein, which is the criterion for its classification as a class II chitinase. Comparison of the genomic and the cDNA sequence revealed that the coding region of Rcht2 consist of three exons of 301, 112, and 370 bp separated by two introns of 89 and 984 bp. In suspension-cultured rice cells, the transcript level of Rcht2 was dramatically increased by treatment with both glycol chitin and fungal elicitor. The application of protein phosphatase 1 and 2A inhibitors, calyculin A and okadaic acid, effectively abolished the induction of Rcht2 in response to fungal elicitor. In contrast, the activation of Rcht2 transcript was not inhibited by both cycloheximide and protein kinase inhibitors. These results demonstrate that protein dephosphorylation events play a crucial role in the elicitor-mediated induction of Rcht2 in rice cells, while de novo protein synthesis is not required for induction.
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Affiliation(s)
- C Y Kim
- Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Chinju, Korea
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Pérez-Callejón E, Casamayor A, Pujol G, Camps M, Ferrer A, Ariño J. Molecular cloning and characterization of two phosphatase 2A catalytic subunit genes from Arabidopsis thaliana. Gene 1998; 209:105-12. [PMID: 9524239 DOI: 10.1016/s0378-1119(98)00013-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The plant Arabidopsis thaliana contains five isoforms of the catalytic subunit of protein phosphatase 2A (PP2A) that can be grouped into two families, one composed by isoforms PP2A-1, -2 and -5 and the other composed by isoforms PP2A-3 and PP2A-4. An Arabidopsis genomic library was screened and several clones corresponding to genes PP2A-3 and PP2A-4 were isolated and analysed. Both genes span over approximately 4.5kbp and are composed of 11 exons and 10 introns that show identical organization. Their untranslated regions are also highly conserved, suggesting that the two genes derive from a common ancestral gene. However, the position of intron/exon junctions completely differs from that of the human PP2A genes. Two transcription start sites have been found in the PP2A-3 gene, the major one mapping at nucleotide position -188 from the translation start codon, whereas only one is observed in PP2A-4 (-145). Functional gene promoter analysis reveals that elements required for transient expression of PP2A-3 and PP2A-4 on a protoplast system are contained within a region of about 600bp upstream from the transcription start sites. This is the first report on the cloning and characterization of genes encoding catalytic subunits of Ser/Thr protein phosphatases 2A in higher plants.
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Affiliation(s)
- E Pérez-Callejón
- Unitat de Bioquímica, Facultat de Farmacia, Universitat de Barcelona, Pça. Pius XII s/n, Barcelona 08028, Spain
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Suh MC, Cho HS, Kim YS, Liu JR, Lee HS. Multiple genes encoding serine/threonine protein phosphatases and their differential expression in Nicotiana tabacum. PLANT MOLECULAR BIOLOGY 1998; 36:315-22. [PMID: 9484443 DOI: 10.1023/a:1005943805988] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Five cDNA clones encoding the catalytic subunits of Ser/Thr protein phosphatases (PP) of Nicotiana tabacum were described. Among them, three clones (NPP1, NPP2, and NPP3) encoded type 1 PP (PP1), whereas the rest of the clones (NPP4 and NPP5) encoded type 2A PP (PP2A). These cDNA clones exhibited high sequence identity in the PP core region to the corresponding genes from animals and plants. NPP1 mRNA was predominantly expressed in flowers, whereas NPP5 mRNA was mainly detected in leaves and flowers. In contrast, the transcripts of NPP2, NPP3, and NPP4 genes were present in all tissues examined. Throughout flower development, NPP1, NPP2, NPP5 mRNAs were expressed without any significant variation at the steady-state level. Genomic Southern blot showed that tobacco genome contained multiple genes and/or pseudogenes for both type 1 and type 2A phosphatases.
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Affiliation(s)
- M C Suh
- Plant Cell and Molecular Biology Research Unit, Korea Research Institute of Bioscience and Biotechnology, Yusong, Taejon, Korea
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40
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Rojo E, Titarenko E, León J, Berger S, Vancanneyt G, Sánchez-Serrano JJ. Reversible protein phosphorylation regulates jasmonic acid-dependent and -independent wound signal transduction pathways in Arabidopsis thaliana. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 1998; 13:153-165. [PMID: 9680973 DOI: 10.1046/j.1365-313x.1998.00020.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Plants responses to mechanical injury are complex and include the induced expression of defence-related genes. The phytohormone JA has been reported to mediate some of these responses. To elucidate further the signal transduction processes involved, the action of specific agonists and antagonists of known signalling effectors on the response of Arabidopsis thaliana plantlets to JA and wounding was investigated. The identification and characterization of a reversible protein phosphorylation step in a transduction pathway leading to JA-induced gene transcription is reported. This phosphorylation event involved the opposing activities of a staurosporine-sensitive protein kinase, negatively regulating the pathway, and a protein phosphatase, most probably of type 2 A, which activated JA-responsive gene expression. JA activation via this pathway was blocked in the A. thaliana JA-insensitive mutants jin1, jin4 and coi1, and by exogenous application of cycloheximide or auxins. Wound-induced activation of JA-responsive genes was also regulated by this protein phosphorylation step. An alternative wound signalling pathway, independent of JA, was also identified, leading to the transcriptional activation of a different set of genes. This JA-independent pathway was also regulated by a protein phosphorylation switch, in which the protein kinase positively regulated the pathway while the protein phosphatase negatively regulated it. Moreover, a labile protein apparently repressed the expression of these genes. One of the genes analysed, JR3, had a complex pattern of expression, possibly because it was regulated via both of the wound signalling pathways identified. According to the function of an homologous gene, JR3 may be involved in feedback inhibition of the JA response.
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Affiliation(s)
- E Rojo
- Centro Nacional de Biotecnología CSIC, Madrid, Spain
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41
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Savino G, Briat JF, Lobréaux S. Inhibition of the iron-induced ZmFer1 maize ferritin gene expression by antioxidants and serine/threonine phosphatase inhibitors. J Biol Chem 1997; 272:33319-26. [PMID: 9407124 DOI: 10.1074/jbc.272.52.33319] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Two pathways have been implicated in the regulation of maize ferritin synthesis in response to iron. One of them involves the plant hormone abscisic acid (ABA) and controls the expression of ZmFer2 gene(s). Another pathway, ABA-independent, has been characterized in a de-rooted maize plantlet system and involves an oxidative step. The ZmFer1 maize ferritin gene is not regulated by ABA, and it is shown in this paper that the corresponding mRNA accumulates in de-rooted maize plantlets and BMS (Black Mexican Sweet) maize cell suspension cultures in response to iron via the oxidative pathway described previously. To investigate ZmFer1 gene regulation further, the BMS cell system has been used to develop a transient expression assay using a ZmFer1-beta-glucuronidase fusion. Both iron induction and antioxidant inhibition of ZmFer1 gene expression were observed in this system. Using Northern blot analysis and transient expression experiments, it was shown that both okadaic acid and calyculin A, two serine/ threonine phosphatase inhibitors, specifically inhibit ZmFer1 gene expression. These data indicate that an okadaic acid-sensitive protein phosphatase activity is involved in the regulation of the ZmFer1 ferritin gene in maize cells, and this activity is required for iron-induced expression of this gene.
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Affiliation(s)
- G Savino
- Laboratoire de Biochimie et Physiologie Moléculaire des Plantes, CNRS (Unité de Recherche 2133), Institut National de la Recherche Agronomique et Ecole Nationale Supérieure d'Agronomie, F-34060 Montpellier cédex 1, France
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Lessard P, Kreis M, Thomas M. [Protein phosphatases and protein kinases in higher plants]. COMPTES RENDUS DE L'ACADEMIE DES SCIENCES. SERIE III, SCIENCES DE LA VIE 1997; 320:675-88. [PMID: 9377173 DOI: 10.1016/s0764-4469(97)84815-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The recent gain in knowledge concerning enzymes involved in signal transduction pathways is a direct consequence of the considerable advances made in molecular biology. Protein kinases and protein phosphatases, the two major enzymes implicated in post-translational modifications, have been studied in particular. The number of characterized plant genes and/or cDNAs encoding these enzymes is increasing everyday. Since 1991, 26 genes and cDNAs coding for plant protein phosphatases have been isolated and characterized. The huge number of protein kinases (estimated at several thousands) makes it impossible to give an exhaustive list of the genes already identified, but a classification of these enzymes, based on phylogenetic criteria, allows us to appreciate the range of functions this protein family may play in plants.
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Affiliation(s)
- P Lessard
- Laboratoire de biologie du développement des plantes, université de Paris-Sud, Orsay, France.
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43
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Hammer MF, Markwell J, Sarath G. Purification of a protein phosphatase from chloroplast stroma capable of dephosphorylating the light-harvesting complex-II. PLANT PHYSIOLOGY 1997; 113:227-33. [PMID: 9064687 PMCID: PMC158134 DOI: 10.1104/pp.113.1.227] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
A protein phosphatase was purified from the stroma of Pea (Pisum sativum L.) chloroplasts that is capable of dephosphorylating synthetic phosphopeptides. Following chromatographic purification of greater than 400-fold, two-dimensional electrophoresis indicated that the stromal protein phosphatase is a 29-kD protein. A similar molecular size was determined for the protein-phosphatase activity using gel-permeation chromatography, indicating that the stromal protein phosphatase is probably a monomer. The purified enzyme was able to dephosphorylate synthetic phosphopeptides, which mimic the thylakoid light-harvesting complex II (LHC-II) N terminus, as well as LHC-II in thylakoid membranes, but did not dephosphorylate the major 64-kD phosphoprotein in the stroma. The stromal protein phosphatase did not discriminate between dephosphorylation of phosphothreonine and phosphoserine residues in synthetic peptide substrates, providing further evidence that this enzyme is distinct from the protein phosphatase localized in thylakoid membranes. The exact physiological role of the stromal protein phosphatase has yet to be determined, but it may function in the dephosphorylation of LHC-II.
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Affiliation(s)
- M F Hammer
- Department of Biochemistry, University of Nebraska, Lincoln 68588-0664, USA
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44
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Guo YL, Roux SJ. Partial purification and characterization of a type 1 protein phosphatase in purified nuclei of pea plumules. Biochem J 1996; 319 ( Pt 3):985-91. [PMID: 8921009 PMCID: PMC1217885 DOI: 10.1042/bj3190985] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
We report the isolation and characterization of a protein Ser/Thr phosphatase from highly purified pea nuclei. In subnuclear fractions, more than 75% of Ser/Thr protein phosphatase activity was associated with the chromatin fraction, whereas the other 25% was in the nuclear membrane/nucleoplasmic fraction when phosphorylase a was used as a substrate. The enzyme was purified approx. 2750-fold to a specific activity of approx. 4000 nmol/min per mg. The molecular mass of the enzyme was 34 kDa as estimated by molecular sieve chromatography, and approx. 40 kDa as estimated by SDS/PAGE. The phosphatase was inhibited by okadaic acid with an IC50 of approx. 15 nM, by rabbit muscle inhibitor 2 with an IC50 of approx. 10 nM, and by microcystin-LR with an IC50 of approx. 0.05 nM. The enzyme did not require Ca2+, Mg2+ or Mn2+ for its activity; instead, these cations showed some inhibitory effects. It was inhibited by NaF or citrate but not by tartrate, molybdate or vanadate under the conditions tested. Its sensitivities towards the various phosphatase inhibitors and its substrate specificity were very similar to those characteristic of the type I Ser/Thr protein phosphatases well studied in animal systems. The enzyme was able to selectively dephosphorylate a 92 kDa nuclear protein that had been phosphorylated by one or more endogenous protein kinases.
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Affiliation(s)
- Y L Guo
- Department of Botany, University of Texas at Austin 78713, USA
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Abstract
Posttranslational modification of proteins by phosphorylation is a universal mechanism for regulating diverse biological functions. Recognition that many cellular proteins are reversibly phosphorylated in response to external stimuli or intracellular signals has generated an ongoing interest in identifying and characterizing plant protein kinases and protein phosphatases that modulate the phosphorylation status of proteins. This review discusses recent advances in our understanding of the structure, regulation, and function of plant protein phosphatases. Three major classes of enzymes have been reported in plants that are homologues of the mammalian type-1, -2A, and -2C protein serine/threonine phosphatases. Molecular genetic and biochemical studies reveal a role for some of these enzymes in signal transduction, cell cycle progression, and hormonal regulation. Studies also point to the presence of additional phosphatases in plants that are unrelated to these major classes.
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Affiliation(s)
- Robert D. Smith
- AgBiotech Center, Rutgers University, New Brunswick, New Jersey 08903-0231, Division of Biological Sciences, University of Missouri, Columbia, Missouri 65211
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Carlberg I, Andersson B. Phosphatase activities in spinach thylakoid membranes-effectors, regulation and location. PHOTOSYNTHESIS RESEARCH 1996; 47:145-156. [PMID: 24301822 DOI: 10.1007/bf00016177] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/1995] [Accepted: 12/04/1995] [Indexed: 06/02/2023]
Abstract
The dephosphorylation of seven phosphoproteins associated with Photosystem II or its chlorophyll a/b antenna in spinach thylakoids, was characterised. The rates were found to fall into two distinct groups. One, rapidly dephosphorylated, consisted of the two subunits (25 and 27 kD) of the major light harvesting complex of Photosystem II (LHC II) and a 12 kD polypeptide of unknown identity. A marked correlation between the dephosphorylation of these three phosphoproteins, strongly suggested that they were all dephosphorylated by the same enzyme. Within this group, the 25 kD subunit was consistently dephosphorylated most rapidly, probably reflecting its exclusive location in the peripheral pool of LHC II. The other group, only slowly dephosphorylated, included several PS II proteins such as the D1 and D2 reaction centre proteins, the chlorophyll-a binding protein CP43 and the 9 kD PS II-H phosphoprotein. No dephosphorylation was observed in either of the two groups in the absence of Mg(2+)-ions. Dephosphorylation of the two LHC II subunits took place in both grana and stroma-exposed regions of the thylakoid membrane. However, deposphorylation in the latter region was significantly more rapid, indicating a preferential dephosphorylation of the peripheral (or 'mobile') LHC II. Dephosphorylation of LHC II was found to be markedly affected by the redox state of thiol-groups, which may suggest a possible regulation of LHC II dephosphorylation involving the ferredoxin-thioredoxin system.
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Affiliation(s)
- I Carlberg
- Department of Biochemistry, Arrhenius Laboratories for Natural Sciences, Stockholm University, S-10691, Stockholm, Sweden
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48
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Roles of Circadian Rhythms, Light and Temperature in the Regulation of Phosphoenolpyruvate Carboxylase in Crassulacean Acid Metabolism. CRASSULACEAN ACID METABOLISM 1996. [DOI: 10.1007/978-3-642-79060-7_4] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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49
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Nakamura H, Satoh W, Hidaka S, Kagaya Y, Ejiri S, Tsutsumi K. Genomic structure of the rice aldolase isozyme C-1 gene and its regulation through a Ca 2+ -mediated protein kinase-phosphatase pathway. PLANT MOLECULAR BIOLOGY 1996; 30:381-385. [PMID: 8616263 DOI: 10.1007/bf00020125] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Complementary and genomic DNA clones coding for aldolase C-1, the fourth-type isozyme of aldolase in rice Oryza sativa L., have been characterized. The organization of the gene is quite similar to those encoding rice aldolase C-a and a maize cytoplasmic-type aldolase, in that introns are located in the same position. Amino acid sequences are highly conserved among cytoplasmic aldolases in plants. Expression of the gene in rice callus is activated by a protein phosphatase inhibitor okadaic acid, and is inhibited in the presence of thapsigargin, a reagent which increases calcium influx into the cytoplasm. The inhibition is rescued by the simultaneous addition of protein kinase inhibitor H-7. Thus, it is suggested that expression of the aldolase C-1 gene is regulated through a signal transduction pathway involving a Ca 2+ -mediated protein kinase-protein phosphatase system.
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Affiliation(s)
- H Nakamura
- Institute for Cell Biology and Genetics, Faculty of Agriculture, Iwate University, Japan
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50
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Biswas S, Biswas BB. Metabolism of myo-inositol phosphates and the alternative pathway in generation of myo-inositol trisphosphate involved in calcium mobilization in plants. Subcell Biochem 1996; 26:287-316. [PMID: 8744269 DOI: 10.1007/978-1-4613-0343-5_10] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- S Biswas
- Department of Biochemistry, Bose Institute, Calcutta, India
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