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Siu, Gavin Ka Yu; Young, Maria L. C.; Chan, Dessy

doi:10.1023/a:1003042431985

Cited by 59 publications

(4 citation statements)

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“…High-performance liquid chromatography (HPLC) analysis showed that the toxin content exhibited periodic variation: toxin content increased rapidly in the late G1 phase and decreased sharply when the cells entered the G2/M phase. This variation was similar to that observed in our previous study [24] but differed from the results of previous studies on Alexandrium [16,18,20,22], which might be caused by species [16,18] or strain specific differences [20,22]. In addition, different culture conditions such as temperature or irradiance might be other possibilities resulting in the difference [16,18,20].…”

Section: Discussionsupporting

confidence: 76%

“…However, PST biosynthesis in Alexandrium tamarense occurs in the early stage of the S phase [19]. Similarly, toxin synthesis in Alexandrium catenella does not occur in the G1 phase but in the S phase or G2/M phase of the cell cycle [20,21]. Although the toxin-producing periods of different species and strains are not consistent, all these results indicate that the production process in dinoflagellates is regulated by the cell cycle and occurs during a specific period of the cell cycle.…”

Section: Introductionmentioning

confidence: 99%

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

Zhang

Lin

et al. 2018

Marine Drugs

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Paralytic shellfish toxins (PSTs) are a group of potent neurotoxic alkaloids that are produced mainly by marine dinoflagellates. PST biosynthesis in dinoflagellates is a discontinuous process that is coupled to the cell cycle. However, little is known about the molecular mechanism underlying this association. Here, we compared global protein expression profiles of a toxigenic dinoflagellate, Alexandrium catenella, collected at four different stages of toxin biosynthesis during the cell cycle, using an isobaric tags for relative and absolute quantification (iTRAQ)-based quantitative proteomic approach. The results showed that toxin biosynthesis occurred mainly in the G1 phase, especially the late G1 phase. In total, 7232 proteins were confidently identified, and 210 proteins exhibited differential expression among the four stages. Proteins involved in protein translation and photosynthetic pigment biosynthesis were significantly upregulated during toxin biosynthesis, indicating close associations among the three processes. Nine toxin-related proteins were detected, and two core toxin biosynthesis proteins, namely, sxtA and sxtI, were identified for the first time in dinoflagellates. Among these proteins, sxtI and ompR were significantly downregulated when toxin biosynthesis stopped, indicating that they played important roles in the regulation of PST biosynthesis. Our study provides new insights into toxin biosynthesis in marine dinoflagellates: nitrogen balance among different biological processes regulates toxin biosynthesis, and that glutamate might play a key modulatory role.

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Section: Discussionsupporting

confidence: 76%

Section: Introductionmentioning

confidence: 99%

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

Zhang

Lin

et al. 2018

Marine Drugs

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“…Phosphate is required as one of the key elements in biosynthesis or regulatory enzymes in PSTs biosynthesis (Cembella 1998). Previous studies on PSTs producing dinoflagellates have shown that P limitation induced toxin production and increased intracellular toxin concentrations (Boyer et al 1987;Anderson et al 1990a;Siu et al 1997;Hwang and Lu 2000;Lippemeier et al 2003). In contrast, some other studies showed that only P limitation did not affect the intracellular toxin concentrations; indeed, toxin content increased with simultaneous N and P limitations (Flynn et al 1994;John and Flynn 2000).…”

Section: Discussionmentioning

confidence: 89%

Growth and toxin production of tropical Alexandrium minutum Halim (Dinophyceae) under various nitrogen to phosphorus ratios

et al. 2009

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Effects of nitrogen to phosphorous (N/P) ratios of two nitrogen sources (nitrate and ammonium) on growth and toxin production of a tropical estuarine dinoflagellate, Alexandrium minutum Halim, were examined using a strain isolated from a bloom at Tumpat Estuary, Malaysia in September 2001. Experiments were carried out in batch cultures, using either nitrate (N-NO 3 ) or ammonium (N-NH 4 ) as the nitrogen source at a constant amount, and with initial N/P ratios ranging from 5 to 500. Cell density, residual N and P in the medium, cellular toxin quota (Q t ), and toxin composition were analyzed throughout the growths. Our results showed that cell densities and growth rates of A. minutum were severely suppressed under high N/ P ratios (>100) in both N-NO 3 and N-NH 4 treatments. Cells tended to be larger at lower growth rate and P-limited cultures. Toxin profile was relatively constant throughout the experiments, with GTX4/GTX1 as the dominant toxin congeners. Cellular toxin quota (Q t ) increased with elevated N/P ratios in both N-NO 3 and N-NH 4 treatments. Toxin production rate, R tox , however was enhanced in N-NH 4 -grown cultures when P was limited, but showed no difference between N-NO 3 -and N-NH 4 -grown cultures when P was replete. Our results clearly showed that N/P ratios as well as the nitrogen compounds not only affected the growth of A. minutum, but also the cellular toxin quota and its toxin production rate.

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“…For example, A. catenella from China Sea showed a dominance of C1,2 toxins, whereas GTX 1 to 4 were minor (<15 mol%) or present as traces [34,35]. The GTXs dominated in A. catenella strains from Hong Kong waters with GTX4 > GTX3 > GTX1 > GTX6 [36]. In contrast, A. catenella from the southern coast of Chile showed a dominance of C1,2 and GTX1,4 [37] or the dominance of GTX 1 to 4, depending on the isolate.…”

Section: Resultsmentioning

confidence: 99%

Influence of Environmental Factors on the Paralytic Shellfish Toxin Content and Profile of Alexandrium catenella (Dinophyceae) Isolated from the Mediterranean Sea

et al. 2013

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Laboratory experiments were designed to study the toxin content and profile of the Alexandrium catenella strain ACT03 (isolated from Thau Lagoon, French Mediterranean) in response to abiotic environmental factors under nutrient-replete conditions. This dinoflagellate can produce various paralytic shellfish toxins with concentrations ranging from 2.9 to 50.3 fmol/cell. The toxin profile was characterized by carbamate toxins (GTX3, GTX4 and GTX5) and N-sulfocarbamoyl toxins (C1, C2, C3 and C4). C2 dominated at 12–18 °C, but only for salinities ranging from 10 to 25 psu, whereas GTX5 became dominant at temperatures ranging from 21 to 30 °C at almost all salinities. There was no significant variation in the cellular toxin amount from 18 °C to 27 °C for salinities ranging between 30 and 40 psu. At salinities of 10 to 25 psu, the toxin concentrations always remained below 20 fmol/cell. Toxin content was stable for irradiance ranging from 10 to 70 μmol photons/m2/s then slightly increased. Overall, the toxin profile was more stable than the toxin content (fmol/cell), except for temperature and/or salinity values different from those recorded during Alexandrium blooms in Thau Lagoon.

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Cited by 59 publications

References 0 publications

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

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

Growth and toxin production of tropical Alexandrium minutum Halim (Dinophyceae) under various nitrogen to phosphorus ratios

Influence of Environmental Factors on the Paralytic Shellfish Toxin Content and Profile of Alexandrium catenella (Dinophyceae) Isolated from the Mediterranean Sea

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