scholarly journals Transcriptional Responses of the Heat Shock Protein 20 (Hsp20) and 40 (Hsp40) Genes to Temperature Stress and Alteration of Life Cycle Stages in the Harmful Alga Scrippsiella trochoidea (Dinophyceae)

Biology ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 408
Author(s):  
Yunyan Deng ◽  
Zhangxi Hu ◽  
Lixia Shang ◽  
Zhaoyang Chai ◽  
Ying Zhong Tang
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Temperature Tolerance ◽  
Intrinsic Stress ◽  
Transcriptional Responses ◽  
Mrna Accumulation ◽  
Scrippsiella Trochoidea ◽  
Resting Cyst

The small heat shock protein (sHsp) and Hsp40 are Hsp members that have not been intensively investigated but are functionally important in most organisms. In this study, the potential roles of a Hsp20 (StHsp20) and a Hsp40 (StHsp40) in dinoflagellates during adaptation to temperature fluctuation and alteration of different life stages were explored using the representative harmful algal blooms (HABs)-causative dinoflagellate species, Scrippsiella trochoidea. We isolated the full-length cDNAs of the two genes via rapid amplification of cDNA ends (RACE) and tracked their differential transcriptions via real-time qPCR. The results revealed StHsp20 and StHsp40 exhibited mRNA accumulation patterns that were highly similar in response to heat stress but completely different toward cold stress, which implies that the mechanisms underlying thermal and cold acclimation in dinoflagellates are regulated by different sets of genes. The StHsp20 was probably related to the heat tolerance of the species, and StHsp40 was closely involved in the adaptation to both higher and lower temperature fluctuations. Furthermore, significantly higher mRNA abundance of StHsp40 was detected in newly formed resting cysts, which might be a response to intrinsic stress stemmed from encystment. This finding also implied StHsp40 might be engaged in resting cyst formation of S. trochoidea. Our findings enriched the knowledge about possible cross-talk of different Hsp members in dinoflagellates and provided clues to further explore the molecular underpinnings underlying resting cyst production and broad temperature tolerance of this group of HABs contributors.

scholarly journals Heat Shock Protein 70 and 90 Genes in the Harmful DinoflagellateCochlodinium polykrikoides: Genomic Structures and Transcriptional Responses to Environmental Stresses

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Ruoyu Guo ◽  
Seok Hyun Youn ◽  
Jang-Seu Ki
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Phylogenetic Analyses ◽  
Expression Patterns ◽  
Genomic Analysis ◽  
Environmental Stresses ◽  
Transcriptional Responses ◽  
Intergenic Spacers

The marine dinoflagellateCochlodinium polykrikoidesis responsible for harmful algal blooms in aquatic environments and has spread into the world’s oceans. As a microeukaryote, it seems to have distinct genomic characteristics, like gene structure and regulation. In the present study, we characterized heat shock protein (HSP) 70/90 ofC. polykrikoidesand evaluated their transcriptional responses to environmental stresses. Both HSPs contained the conserved motif patterns, showing the highest homology with those of other dinoflagellates. Genomic analysis showed that theCpHSP70had no intron but was encoded by tandem arrangement manner with separation of intergenic spacers. However,CpHSP90had one intron in the coding genomic regions, and no intergenic region was found. Phylogenetic analyses of separate HSPs showed that CpHSP70 was closely related with the dinoflagellateCrypthecodinium cohniiand CpHSP90 with other Gymnodiniales in dinoflagellates. Gene expression analyses showed that bothHSPgenes were upregulated by the treatments of separate algicides CuSO4and NaOCl; however, they displayed downregulation pattern with PCB treatment. The transcription ofCpHSP90andCpHSP70showed similar expression patterns under the same toxicant treatment, suggesting that both genes might have cooperative functions for the toxicant induced gene regulation in the dinoflagellate.

scholarly journals Expression Patterns of the Heat Shock Protein 90 (Hsp90) Gene Suggest Its Possible Involvement in Maintaining the Dormancy of Dinoflagellate Resting Cysts

2021 ◽  
Vol 22 (20) ◽  
pp. 11054
Author(s):  
Yunyan Deng ◽  
Fengting Li ◽  
Zhangxi Hu ◽  
Caixia Yue ◽  
Ying Zhong Tang
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Life Stage ◽  
Expression Patterns ◽  
Heat Shock Protein 90 ◽  
Model Organisms ◽  
Cyst Production ◽  
Resting Cysts

Heat shock protein 90 (Hsp90) is a highly conserved molecular chaperone functioning in cellular structural folding and conformational integrity maintenance and thus plays vital roles in a variety of biological processes. However, many aspects of these functions and processes remain to be fully elucidated, particularly for non-model organisms. Dinoflagellates are a group of eukaryotes that are exceedingly important in primary production and are responsible for the most harmful algal blooms (HABs) in aquatic ecosystems. The success of dinoflagellates in dominating the plankton community is undoubtedly pertinent to their remarkable adaptive strategies, characteristic of resting cyst production and broad tolerance to stresses of temperature and others. Therefore, this study was conducted to examine the putative roles of Hsp90 in the acclimation to temperature stress and life stage alterations of dinoflagellates. Firstly, we isolated the full-length cDNA of an Hsp90 gene (StHsp90) via RACE from the cosmopolitan HAB species Scrippsiella trochoidea and tracked its transcriptions in response to varied scenarios via real-time qPCR. The results indicated that StHsp90 displayed significant mRNA augment patterns, escalating during 180-min treatments, when the cells were exposed to elevated and lowered temperatures. Secondly, we observed prominently elevated StHsp90 transcriptions in the cysts that were stored at the cold and dark conditions compared to those in newly formed resting cysts and vegetative cells. Finally, and perhaps most importantly, we identified 29 entries of Hsp90-encoding genes with complete coding regions from a dinoflagellate-specific environmental cDNA library generated from marine sediment assemblages. The observed active transcription of these genes in sediment-buried resting cysts was fully supported by the qPCR results for the cold-stored resting cysts of S. trochoidea. Hsp90s expressions in both laboratory-raised and field-collected cysts collectively highlighted the possible involvement and engagement of Hsp90 chaperones in the resting stage persistence of dinoflagellates.

scholarly journals Probing the Energetic Metabolism of Resting Cysts under Different Conditions from Molecular and Physiological Perspectives in the Harmful Algal Blooms-Forming Dinoflagellate Scrippsiella trochoidea

2021 ◽  
Vol 22 (14) ◽  
pp. 7325
Author(s):  
Fengting Li ◽  
Aoao Yang ◽  
Zhangxi Hu ◽  
Siheng Lin ◽  
Yunyan Deng ◽  
...  
Keyword(s):  
Low Temperature ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Atp Content ◽  
Energetic Metabolism ◽  
Scrippsiella Trochoidea ◽  
Vegetative Cells ◽  
F1 Atpase ◽  
Atpase Gene ◽  
Resting Cysts

Energetic metabolism is essential in maintaining the viability of all organisms. Resting cysts play important roles in the ecology of dinoflagellates, particularly for harmful algal blooms (HABs)-causative species. However, the energetic metabolism underlying the germination potency maintenance of resting cysts of dinoflagellate have been extremely scarce in studies from physiological and, particularly, molecular perspectives. Therefore, we used the cosmopolitan Scrippsiella trochoidea as a representative of HABs-forming and cyst-producing dinoflagellates in this work to obtain novel insights into the molecular mechanisms, regulating the energetic metabolism in dinoflagellate resting cysts, under different physical condition. As the starting step, we established a cDNA subtractive library via suppression subtractive hybridization (SSH) technology, from which we screened an incomplete sequence for the β subunit of ATP synthase gene (β-F1-ATPase), a key indicator for the status of cell’s energetic metabolism. The full-length cDNA of β-F1-ATPase gene from S.trochoidea (Stβ-F1-ATPase) was then obtained via rapid amplification of cDNA ends (RACE) (Accession: MZ343333). Our real-time qPCR detections, in vegetative cells and resting cysts treated with different physical conditions, revealed that (1) the expression of Stβ-F1-ATPase in resting cysts was generally much lower than that in vegetative cells, and (2) the Stβ-F1-ATPase expressions in the resting cysts under darkness, lowered temperature, and anoxia, and during an extended duration of dormancy, were significantly lower than that in cysts under the condition normally used for culture-maintaining (a 12 h light:12 h dark cycle, 21 °C, aerobic, and newly harvested). Our detections of the viability (via Neutral Red staining) and cellular ATP content of resting cysts, at the conditions corresponding to the abovementioned treatments, showed that both the viability and ATP content decreased rapidly within 12 h and then maintained at low levels within the 4-day experimentation under all the three conditions applied (4 °C, darkness, and anoxia), which are well in accordance with the measurements of the transcription of Stβ-F1-ATPase. These results demonstrated that the energy consumption of resting cysts reaches a low, but somehow stable, level within a short time period and is lower at low temperature, darkness, and anoxia than that at ambient temperature. Our work provides an important basis for explaining that resting cysts survive long-term darkness and low temperature in marine sediments from molecular and physiological levels.

Effects of cycloheximide on thermotolerance expression, heat shock protein synthesis, and heat shock protein mRNA accumulation in rat fibroblasts

1986 ◽  
Vol 6 (4) ◽  
pp. 1088-1094
Author(s):  
R B Widelitz ◽  
B E Magun ◽  
E W Gerner
Keyword(s):  
Protein Synthesis ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Mrna Levels ◽  
Hsp 70 ◽  
Mrna Accumulation ◽  
General Protein Synthesis ◽  
Rat Fibroblasts ◽  
General Protein ◽  
Rat Embryonic Fibroblasts

A single hyperthermic exposure can render cells transiently resistant to subsequent high temperature stresses. Treatment of rat embryonic fibroblasts with cycloheximide for 6 h after a 20-min interval at 45 degrees C inhibits protein synthesis, including heat shock protein (hsp) synthesis, and results in an accumulation of hsp 70 mRNA, but has no effect on subsequent survival responses to 45 degrees C hyperthermia. hsp 70 mRNA levels decreased within 1 h after removal of cycloheximide but then appeared to stabilize during the next 2 h (3 h after drug removal and 9 h after heat shock). hsp 70 mRNA accumulation could be further increased by a second heat shock at 45 degrees C for 20 min 6 h after the first hyperthermic exposure in cycloheximide-treated cells. Both normal protein and hsp synthesis appeared increased during the 6-h interval after hyperthermia in cultures which received two exposures to 45 degrees C for 20 min compared with those which received only one treatment. No increased hsp synthesis was observed in cultures treated with cycloheximide, even though hsp 70 mRNA levels appeared elevated. These data indicate that, although heat shock induces the accumulation of hsp 70 mRNA in both normal and thermotolerant cells, neither general protein synthesis nor hsp synthesis is required during the interval between two hyperthermic stresses for Rat-1 cells to express either thermotolerance (survival resistance) or resistance to heat shock-induced inhibition of protein synthesis.

scholarly journals A Novel Cyclophilin B Gene in the Red Tide DinoflagellateCochlodinium polykrikoides: Molecular Characterizations and Transcriptional Responses to Environmental Stresses

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Sofia Abassi ◽  
Hui Wang ◽  
Bum Soo Park ◽  
Jong-Woo Park ◽  
Jang-Seu Ki
Keyword(s):  
Stress Responses ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Red Tide ◽  
Economic Loss ◽  
Cell Physiology ◽  
Transcriptional Responses ◽  
Splice Leader ◽  
Cyclophilin B ◽  
Cell Counts

The marine dinoflagellateCochlodinium polykrikoidesis one of the most common ichthyotoxic species that causes harmful algal blooms (HABs), which leads to ecological damage and huge economic loss in aquaculture industries. Cyclophilins (CYPs) belong to the immunophilin superfamily, and they may play a role in the survival mechanisms of the dinoflagellate in stress environments. In the present study, we identified a novel cyclophilin gene fromC. polykrikoidesand examined physiological and gene transcriptional responses to biocides copper sulphate (CuSO4) and sodium hypochlorite (NaOCl). The full length ofCpCYPwas 903 bp, ranging from the dinoflagellate splice leader (DinoSL) sequence to the polyA tail, comprising a 639 bp ORF, a 117 bp 5′-UTR, and a 147 bp 3′-UTR. Motif and phylogenetic comparisons showed that CpCYP was affiliated to group B of CYP. In biocide stressors, cell counts, chlorophylla, and photosynthetic efficiency (Fv/Fm) ofC. polykrikoideswere considerably decreased in both exposure time- and dose-dependent manners. In addition,CpCYPgene expression was significantly induced after 24 h exposure to the biocide-treated stress conditions. These results indicate an effect of the biocides on the cell physiology and expression profile ofCpCYP, suggesting that the gene may play a role in environmental stress responses.

Enhanced accumulation of constitutive heat shock protein mRNA is an initial response of eye tissue to mild hyperthermia in vivo in adult Xenopus laevis

2002 ◽  
Vol 80 (11) ◽  
pp. 1119-1123 ◽  
Author(s):  
Adnan Ali ◽  
John J Heikkila
Keyword(s):  
Heat Shock ◽  
Xenopus Laevis ◽  
Heat Shock Protein ◽  
Specific Interaction ◽  
Initial Response ◽  
Heat Shock Element ◽  
Mrna Accumulation ◽  
Mild Hyperthermia ◽  
Hsp Genes

We have examined the effect of mild hyperthermia in vivo on heat shock transcription factor (HSF) binding activity and heat shock protein (hsp) gene expression in eye tissue of adult Xenopus laevis. A specific interaction between HSF and a synthetic oligonucleotide corresponding to the proximal heat shock element of the Xenopus hsp70B gene was greatly enhanced in eyes from hyperthermic animals compared with controls. Given these results, we examined the effect of hyperthermia in vivo on the expression of five hsp genes (hsp70, hsc70, BiP, hsp90, and hsp30) in eye tissue. Interestingly, at 28°C constitutively expressed hsp genes hsc70, BiP, and hsp90 were strongly enhanced, with further accumulation at 30°C. However, hsp70 and hsp30 mRNA accumulation were not detectable at 28°C but were strongly induced at 30°C. No enhancement of the relative levels of cytoskeletal actin mRNA was observed in the eye tissue of hyperthermic animals. These results suggest that one of the primary responses of eye tissue to hyperthermia in vivo is in the elevation of mRNAs encoding a set of constitutively expressed molecular chaperones.Key words: Xenopus, mRNA, eye, heat shock, heat shock factor.

scholarly journals Effects of cycloheximide on thermotolerance expression, heat shock protein synthesis, and heat shock protein mRNA accumulation in rat fibroblasts.

1986 ◽  
Vol 6 (4) ◽  
pp. 1088-1094 ◽  
Author(s):  
R B Widelitz ◽  
B E Magun ◽  
E W Gerner
Keyword(s):  
Protein Synthesis ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Mrna Levels ◽  
Hsp 70 ◽  
Mrna Accumulation ◽  
General Protein Synthesis ◽  
Rat Fibroblasts ◽  
General Protein ◽  
Rat Embryonic Fibroblasts

A single hyperthermic exposure can render cells transiently resistant to subsequent high temperature stresses. Treatment of rat embryonic fibroblasts with cycloheximide for 6 h after a 20-min interval at 45 degrees C inhibits protein synthesis, including heat shock protein (hsp) synthesis, and results in an accumulation of hsp 70 mRNA, but has no effect on subsequent survival responses to 45 degrees C hyperthermia. hsp 70 mRNA levels decreased within 1 h after removal of cycloheximide but then appeared to stabilize during the next 2 h (3 h after drug removal and 9 h after heat shock). hsp 70 mRNA accumulation could be further increased by a second heat shock at 45 degrees C for 20 min 6 h after the first hyperthermic exposure in cycloheximide-treated cells. Both normal protein and hsp synthesis appeared increased during the 6-h interval after hyperthermia in cultures which received two exposures to 45 degrees C for 20 min compared with those which received only one treatment. No increased hsp synthesis was observed in cultures treated with cycloheximide, even though hsp 70 mRNA levels appeared elevated. These data indicate that, although heat shock induces the accumulation of hsp 70 mRNA in both normal and thermotolerant cells, neither general protein synthesis nor hsp synthesis is required during the interval between two hyperthermic stresses for Rat-1 cells to express either thermotolerance (survival resistance) or resistance to heat shock-induced inhibition of protein synthesis.

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