title: Cellular metabolic responses of the marine diatom Pseudo-nitzschia multiseries associated with cell wall formation.
abstract: In this study a comparative proteomics approach involving a mass spectrometric analysis of synchronized cells was employed to investigate the cellular-level metabolic mechanisms associated with siliceous cell wall formation in the pennate diatom Pseudo-nitzschia multiseries. Cultures of P. multiseries were synchronized using the silicate limitation method. Approximately 75% of cells were arrested at the G2+M phase of the cell cycle after 48 h of silicate starvation. The majority of cells progressed to new valve synthesis within 5h of silicon replenishment. We compared the proteome of P. multiseries at 0, 4, 5, and 6h of synchronization progress upon silicon replenishment using two-dimensional gel electrophoresis. Forty-eight differentially expressed protein spots were identified in abundance (greater than two-fold change; P<0.005), some of which are predicted to be involved in intracellular trafficking, cytoskeleton, photosynthesis, lipid metabolism, and protein biosynthesis. Cytoskeleton proteins and clathrin coat components were also hypothesized to play potential roles in cell wall formation. The proteomic profile analysis suggests that P. multiseries most likely employs multiple synergistic biochemical mechanisms for cell wall formation. These results improve our understanding of the molecular mechanisms underlying silicon cell wall formation and enhance our understanding of the important role played by diatoms in silicon biogeochemical cycling.
authors.affiliation: School of Life Sciences, Xiamen University, Xiamen 361005, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Xu
authors.affiliation: School of Life Sciences, Xiamen University, Xiamen 361005, China.
authors.forename: Chun-Shan
authors.initials: CS
authors.lastname: Luo
authors.affiliation: School of Life Sciences, Xiamen University, Xiamen 361005, China; Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen University, Xiamen 361005, China. Electronic address: sunljr@xmu.edu.cn.
authors.forename: Jun-Rong
authors.initials: JR
authors.lastname: Liang
authors.affiliation: School of Life Sciences, Xiamen University, Xiamen 361005, China.
authors.forename: Dan-Dan
authors.initials: DD
authors.lastname: Chen
authors.affiliation: School of Life Sciences, Xiamen University, Xiamen 361005, China.
authors.forename: Wen-Hao
authors.initials: WH
authors.lastname: Zhuo
authors.affiliation: School of Life Sciences, Xiamen University, Xiamen 361005, China; Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen University, Xiamen 361005, China.
authors.forename: Ya-Hui
authors.initials: YH
authors.lastname: Gao
authors.affiliation: School of Life Sciences, Xiamen University, Xiamen 361005, China; Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen University, Xiamen 361005, China.
authors.forename: Chang-Ping
authors.initials: CP
authors.lastname: Chen
authors.affiliation: School of Life Sciences, Xiamen University, Xiamen 361005, China.
authors.forename: Si-Si
authors.initials: SS
authors.lastname: Song
mesh_terms: D059001:Aquatic Organisms / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D002473:Cell Wall / Q000235:genetics / Q000378:metabolism*; D017377:Diatoms / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D020543:Proteome; D012825:Silicon / Q000378:metabolism
chemical_list: D020543:Proteome; D012825:Silicon
keywords: Biosilicification; Cellular metabolism; Comparative proteomics; Diatom; Pseudo-nitzschia multiseries