Effect of different environmental variables on the synthesis of Hsp70 in Raphidocelis subcapitata

Bierkens, Johan; Perre, Wendy Van de; Maes, Jef

doi:10.1016/s1095-6433(98)10006-5

Cited by 23 publications

(8 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…exposure to acidic conditions, has been well studied in microorganisms (Heyde & Portalier, 1990;Hartke et al, 1996;Wang & Doyle, 1998;Angelis et al, 2001;Periago et al, 2002;Len et al, 2004). We are aware of only one other study that has examined the response of Hsps to pH in a eukaryotic microorganism (Bierkens et al, 1998), where it was demonstrated that Hsp70 was induced as a result of external acidification in the green alga Raphidocelis subcapitata. In addition, the induction of Hsps using a mild heat-shock increases the tolerance of microorganisms to acidic conditions (Wang & Doyle, 1998), a phenomenon known as cross-protection, or cross-tolerance.…”

Section: Introductionmentioning

confidence: 99%

“…However, pHinduced accumulation of Hsps has been studied primarily in prokaryotes. We are aware of only one other study that has examined the response of Hsps to pH in a eukaryotic microorganism (Bierkens et al, 1998), where it was demonstrated that Hsp70 was induced as a result of external acidification in the green alga Raphidocelis subcapitata.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Temperature- and pH-dependent accumulation of heat-shock proteins in the acidophilic green alga Chlamydomonas acidophila

Gerloff‐Elias

Barua

Mölich

et al. 2006

FEMS Microbiology Ecology

View full text Add to dashboard Cite

Chlamydomonas acidophila, a unicellular green alga, is a dominant phytoplankton species in acidic water bodies, facing severe environmental conditions such as low pH and high heavy metal concentrations. We examined the pH-, and temperature-dependent accumulation of heat-shock proteins in this alga to determine whether heat-shock proteins play a role in adaptation to their environment. Our results show increased heat-shock proteins accumulation at suboptimal pHs, which were not connected with any change in intracellular pH. In comparison to the mesophilic Chlamydomonas reinhardtii, the acidophilic species exhibited significantly higher accumulations of heat-shock proteins under control conditions, indicating an environmental adaptation of increased basal levels of heat-shock proteins. The results suggest that heat-shock proteins might play a role in the adaptation of C. acidophila, and possibly other acidophilic algae, to their extreme environment.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Temperature- and pH-dependent accumulation of heat-shock proteins in the acidophilic green alga Chlamydomonas acidophila

Gerloff‐Elias

Barua

Mölich

et al. 2006

FEMS Microbiology Ecology

View full text Add to dashboard Cite

show abstract

“…Temperature and pH were found to induce acquired tolerance; that is, algae grown at a pH or at a temperature different from control conditions were shown to have acquired resistance to a subsequent challenge with Zn (10 5 M). These results qualify HSP70 as a biomonitor for environmental pollution provided that essential environmental parameters such as pH and temperature are kept constant [108]. Apart from temperature and pH, much similar emphasis has also been placed on the analysis of nutrients, electrolytes, and dissolved oxygen content [105].…”

Section: Discussion: Critical Analysismentioning

confidence: 99%

Synergistic Effects of Toxic Elements on Heat Shock Proteins

Kazemzad¹,

Jadoon

Mahmood

et al. 2014

BioMed Research International

View full text Add to dashboard Cite

Heat shock proteins show remarkable variations in their expression levels under a variety of toxic conditions. A research span expanded over five decades has revealed their molecular characterization, gene regulation, expression patterns, vast similarity in diverse groups, and broad range of functional capabilities. Their functions include protection and tolerance against cytotoxic conditions through their molecular chaperoning activity, maintaining cytoskeleton stability, and assisting in cell signaling. However, their role as biomarkers for monitoring the environmental risk assessment is controversial due to a number of conflicting, validating, and nonvalidating reports. The current knowledge regarding the interpretation of HSPs expression levels has been discussed in the present review. The candidature of heat shock proteins as biomarkers of toxicity is thus far unreliable due to synergistic effects of toxicants and other environmental factors. The adoption of heat shock proteins as “suit of biomarkers in a set of organisms” requires further investigation.

show abstract

“…As one clear response to HS exposure, defense proteins (better known as heat shock proteins -Hsp) were expressed in freshwater animals and algae (Bierkens et al 1998). Even environmentally realistic HS concentrations induced increased Hsp70 concentrations in the test organisms.…”

Section: Further Chemical Stress Defense Reactions: Hsp Biotransformmentioning

confidence: 99%

Humic substances

Steinberg

Meinelt

Timofeyev

et al. 2007

Environ Sci Pollut Res

113

View full text Add to dashboard Cite

(stress proteins), induction and modulation of biotransformation and anti-oxidant enzymes. Furthermore, they produce an oxidative stress with lipidperoxidation as one clear symptom or even stress defense strategy. Stronger chemical stresses by HS may even lead to teratogenic effects as shown with fish embryos; all physiological responses to HS-mediated stress require energy, which were compensated on the expense of yolk as shown with zebra fish embryos. One Finnish field survey supports the view of a strong chemical stress, as the weight yield in fish species decreases with increasing HS content in the lakes. Discussion. HS exert a variety of stress symptoms in aquatic and compost organisms. According to current paradigms of ecotoxicology, these symptoms have to be considered adverse, because their compensation consumes energy which is deducted from the main metabolism. However, the nematode C. elegans looks actively for such stressful environments, and this behavior is only understandable in the light of new paradigms of aging mechanisms, particularly the Green Theory of Aging. In this respect, we discuss the mild HS-mediated stress to aquatic and compost organisms. New empirical findings with HS themselves and HS building blocks appear to be consistent with this emerging paradigm and show that the individual lifespan may be expanded. At present the ecological consequences of these findings remain obscure. However, a multiple-stress resistance may be acquired which improves the individual fitness in a fluctuating environment.Conclusions. It appears that dissolved HS have to be considered abiotic ecological driving forces, somewhat less obvious than temperature, nutrients, or light.Perspectives. The understanding of the ecological control by dissolved humic substances is still fragmentary and needs to be studied in more details.Keywords: Chemical stress defense; dissolved humic substances; feminization; longevity; membrane irritation; multiple stress resistance; natural herbicides; natural organic matter (NOM); teratogenic effects AbstractGoal, Scope and Background. Freshwater bodies which chemistry is dominated by dissolved humic substances (HS) seem to be the major type on Earth, due to huge non-calcareous geological formations in the Northern Hemisphere and in the tropics. Based on the paradigm of the inertness of being organic, direct interactions of dissolved HS with freshwater organisms are mostly neglected. However, dissolved organic carbon, the majority of which being HS, are natural environmental chemicals and should therefore directly interact with organisms. Major results that widened our perspective on humic substance ecology come from experiments with the compost nematode, Caenorhabditis elegans, which behaved contradictorily to textbook knowledge and provoked an in-depth re-consideration of some paradigms. Approach. To overcome old paradigms on HS and their potential interactions with organisms, we reviewed recent international literature, as well as 'grey' literature. We also include results from...

show abstract

Effect of different environmental variables on the synthesis of Hsp70 in Raphidocelis subcapitata

Cited by 23 publications

References 12 publications

Temperature- and pH-dependent accumulation of heat-shock proteins in the acidophilic green alga Chlamydomonas acidophila

Temperature- and pH-dependent accumulation of heat-shock proteins in the acidophilic green alga Chlamydomonas acidophila

Synergistic Effects of Toxic Elements on Heat Shock Proteins

Humic substances

Contact Info

Product

Resources

About