Relationship of proteomic variation and toxin synthesis in the dinoflagellate Alexandrium tamarense CI01 under phosphorus and inorganic nitrogen limitation

Abstract

Paralytic shellfish toxins (PSTs) are originated from cyanobacteria and dinoflagellates, including Alexandrium tamarense, the common dinoflagellate species. In this study, a toxic dinoflagellate strain of A. tamarense CI01 was selected for studying the PSTs' concentration and the related protein variation during the whole cell cycle under different nutrient conditions. High-performance liquid chromatography, 2-D DIGE and Western blotting were used collectively for protein profiling and identification. Results showed that the toxin content was suppressed under nitrogen limiting condition, but enhanced in phosphorous limiting medium. Based on the results of proteomics analysis, 7 proteins were discovered to be related to the PSTs biosynthesis of A. tamarense CI01, including S-adenosylhomocysteine hydrolase, ornithine cyclodeaminase, argininosuccinate synthase, methyluridine methyltransferase cystine ABC transporter, phosphoserine phosphatase, argininosuccinate synthase and acyl-CoA dehydrogenase, which corresponds to the metabolism of the methionine, cysteine, ornithine, arginine and proline. Moreover, some photosynthesis relating proteins also increased their expression during PST synthesis period in A. tamarense CI01, such as phosphoenolpyruvate carboxylase, chloroplast phosphoglycerate kinase, peridinin-chlorophyll α-binding protein, Mg(2+) transporter protein and chloroplast phosphoglycerate kinase. The above findings are in support of our hypothesis that these proteins are involved in toxin biosynthesis of A. tamarense CI01, but cause-and-effect mechanisms need to be investigated in further studies.

Biosynthesis of Saxitoxin in Marine Dinoflagellates: An Omics Perspective

“…In another investigation, the proteomics analysis of mutated saxitoxin-producing A. catenella exposed to a cell-cycle inhibitor colchicine revealed the upregulation of several proteins involved in photosynthesis and carotenoid biosynthesis during the arrested toxin production stage, indicating the channeling of nitrogen compounds originally allocated for saxitoxin biosynthesis toward the synthesis of carotenoid and nitrogenous chlorophyll [96]. However, these claims can be contended with a finding by Jiang et al [97] of several photosynthesis-related proteins having enhanced expression during the highly toxic period of saxitoxin-producing A. tamarense, which can be reflected back to a study by Etheridge and Roesler [98] that was unable to find a significant correlation between photosynthesis rate and toxin production in the toxic A. fundyense. Thus, it is unclear whether the rate of photosynthesis and growth rate directly affect saxitoxin biosynthesis in dinoflagellates or if the observations were just the effects of random mutation as shown in the case of the non-toxic mutant of A. catenella.…”

iTRAQ-Based Quantitative Proteomic Analysis of a Toxigenic Dinoflagellate Alexandrium catenella at Different Stages of Toxin Biosynthesis during the Cell Cycle

“…In previous studies, PST biosynthesis has been proposed to be closely associated with chloroplast biosynthesis. PSTs and chlorophyll are thought to share the same polyketide precursor [40]. Chlorophyll formation starts from the synthesis of ALA, where gltX and hemL are the two enzymes that catalyze the conversion of glutamate to ALA [33,34].…”

Coastal and marine pollution and ecotoxicology

“…Oceans and coastal ecosystems are both important to humans, and protection and conservation will allow future sustainable development and also the human long-term survival (Mitchell and Gu 2010;Shen et al 2010; Wang 2012, 2013a). The changes documented and reported in China today can be very useful information and mirror images for the changes to be observed in other developing countries, if not now but in the near future.Pollution as a phenomenon closely associated with human society has distinctive phases over time of the history and it includes sewage, toxic chemicals of metals and metalloids and also persistent organic compounds, harmful organisms from toxic algae including dinoflagellates, bacteria and viruses, and more recently the emerging new chemicals of pharmaceuticals and personal care products (Gu and Wang 2013b; Mitchell and Gu 2010;Jiang et al 2015). This changing trend of different chemicals over time illustrates not only the technological advances in our society and analytical chemistry driving the environmental understanding and study, but also the consumer attitude and habits of our society altering the pollutant types.…”

“…Pollution as a phenomenon closely associated with human society has distinctive phases over time of the history and it includes sewage, toxic chemicals of metals and metalloids and also persistent organic compounds, harmful organisms from toxic algae including dinoflagellates, bacteria and viruses, and more recently the emerging new chemicals of pharmaceuticals and personal care products (Gu and Wang 2013b;Mitchell and Gu 2010;Jiang et al 2015). This changing trend of different chemicals over time illustrates not only the technological advances in our society and analytical chemistry driving the environmental understanding and study, but also the consumer attitude and habits of our society altering the pollutant types.…”

“…Because of our thirst for energy, petroleum is widely and increasing consumed as the major energy source, but pollution and oil spills are notable widely. Similarly, wastewater is also part of life style, it contaminates the rivers and streams and also coastal ecosystems, resulting in serious eutrophication and harmful algal bloom, killing fishes and other organisms (Cao et al 2013;Jiang et al 2015). Drinking water quality is a much wide issue of common interest and contamination of food and beverages by plasticizers are still facing the public and the developing countries (Gu and Wang 2013b).…”