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The co-expression of denileukin diftitox immunotoxin with Artemin: soluble and aggregation analysis in presence of an efficient protein chaperone. Biologia (Bratisl) 2021. [DOI: 10.1007/s11756-021-00846-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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MacRae TH. Stress tolerance during diapause and quiescence of the brine shrimp, Artemia. Cell Stress Chaperones 2016; 21:9-18. [PMID: 26334984 PMCID: PMC4679736 DOI: 10.1007/s12192-015-0635-7] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Revised: 08/12/2015] [Accepted: 08/24/2015] [Indexed: 02/06/2023] Open
Abstract
Oviparously developing embryos of the brine shrimp, Artemia, arrest at gastrulation and are released from females as cysts before entering diapause, a state of dormancy and stress tolerance. Diapause is terminated by an external signal, and growth resumes if conditions are permissible. However, if circumstances are unfavorable, cysts enter quiescence, a dormant stage that continues as long as adverse conditions persist. Artemia embryos in diapause and quiescence are remarkably resistant to environmental and physiological stressors, withstanding desiccation, cold, heat, oxidation, ultraviolet radiation, and years of anoxia at ambient temperature when fully hydrated. Cysts have adapted to stress in several ways; they are surrounded by a rigid cell wall impermeable to most chemical compounds and which functions as a shield against ultraviolet radiation. Artemia cysts contain large amounts of trehalose, a non-reducing sugar thought to preserve membranes and proteins during desiccation by replacing water molecules and/or contributing to vitrification. Late embryogenesis abundant proteins similar to those in seeds and other anhydrobiotic organisms are found in cysts, and they safeguard cell organelles and proteins during desiccation. Artemia cysts contain abundant amounts of p26, a small heat shock protein, and artemin, a ferritin homologue, both ATP-independent molecular chaperones important in stress tolerance. The evidence provided in this review supports the conclusion that it is the interplay of these protective elements that make Artemia one of the most stress tolerant of all metazoan organisms.
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Affiliation(s)
- Thomas H MacRae
- Department of Biology, Dalhousie University, Halifax, N.S., B3H 4R2, Canada.
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3
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Deletion of extra C-terminal segment and its effect on the function and structure of artemin. Int J Biol Macromol 2011; 49:311-6. [DOI: 10.1016/j.ijbiomac.2011.05.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Revised: 05/05/2011] [Accepted: 05/05/2011] [Indexed: 11/24/2022]
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Sequence and structural analysis of artemin based on ferritin: a comparative study. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2009; 1794:1407-13. [PMID: 19486949 DOI: 10.1016/j.bbapap.2009.05.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2009] [Revised: 05/06/2009] [Accepted: 05/26/2009] [Indexed: 11/24/2022]
Abstract
Artemia cysts can tolerate extreme environments, partly due to a heat-stable protein called artemin. According to previous studies, artemin shares structural similarity with ferritins. Actually, there is still no strong structural information about artemin three-dimensional (3-D) structure. In this research, the artemin encoding gene from Artemia urmiana was cloned and sequenced. A reliable 3-D model of artemin was initially built using ferritin as template and refined using Molecular Dynamic (MD) Simulation. It is interesting that the proposed model, confirmed by circular dichroism (CD), shows significant differences in secondary structure contents with ferritin. Three conserved regions (ferroxidase center, iron nucleation center and 3-fold channel) in ferritins, cooperating in iron-interaction, have been substantially changed in artemin. Analysis of C-terminal region of the model revealed its major role in preventing artemin from iron-binding due to some suitable interactions. Finally, it is concluded that significant differences between artemin and ferritin, both in conserved regions related to iron-interaction and three-dimensional structure, can justify their functional differences.
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Clegg JS, Gajardo G. Two highly diverged New World Artemia species, A. franciscana and A. persimilis, from contrasting hypersaline habitats express a conserved stress protein complement. Comp Biochem Physiol A Mol Integr Physiol 2009; 153:451-6. [PMID: 19379819 DOI: 10.1016/j.cbpa.2009.04.613] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2009] [Revised: 04/08/2009] [Accepted: 04/08/2009] [Indexed: 11/18/2022]
Abstract
The brine shrimp Artemia is a well known animal extremophile adapted to survive in very harsh hypersaline environments. We compared the small stress proteins artemin and p26, and the chaperone hsc70 in encysted embryos (cysts) of the New World species, A. franciscana and A. persimilis. Cysts of the former, from San Francisco Bay, USA (SFB), were used essentially as a reference for these proteins, while both species were from locations in Chile where they occur in habitats at latitudinal extremes, the Atacama desert and Patagonia. These two species are phylogenetically distant, A. persimilis being closer to the Old World species, whilst A. franciscana is considered younger and undergoing evolutionary expansion. Using western blotting we found all three stress proteins in cysts from these five populations in substantial although variable amounts. The protein profiles revealed by Coomassie staining after electrophoresis (SDS-PAGE) were similar qualitatively, in spite of marked differences in the habitats from which these populations originated, and the long time since they diverged. We interpret these findings as further evidence for the adaptive importance of these three conserved proteins in coping with the variable, but severe stresses these encysted embryos endure.
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Affiliation(s)
- James S Clegg
- Bodega Marine Laboratory and Section of Molecular and Cellular Biology, University of California, Davis, Bodega Bay, CA 94923, USA.
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6
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Clegg JS. Protein stability in Artemia embryos during prolonged anoxia. THE BIOLOGICAL BULLETIN 2007; 212:74-81. [PMID: 17301333 DOI: 10.2307/25066582] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Encysted embryos (cysts) of the brine shrimp, Artemia franciscana, are arguably the most stress-resistant of all animal life-history stages. One of their many adaptations is the ability to tolerate anoxia for periods of years, while fully hydrated and at physiological temperatures. Previous work indicated that the overall metabolism of anoxic embryos is brought to a reversible standstill, including the transduction of free energy and the turnover of macromolecules. But the issue of protein stability at the level of tertiary and quaternary structure was not examined. Here I provide evidence that the great majority of proteins do not irreversibly lose their native conformation during years of anoxia, despite the absence of detectable protein turnover. Although a modest degree of protein denaturation and aggregation occurs, that is quickly reversed by a brief post-anoxic aerobic incubation. I consider how such extraordinary stability is achieved and suggest that at least part of the answer involves massive amounts of a small heat shock protein (p26) that acts as a molecular chaperone, the function of which does not appear to require ribonucleoside di- or tri-phosphates.
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Affiliation(s)
- James S Clegg
- Section of Molecular & Cellular Biology, and Bodega Marine Laboratory, University of California (Davis), Bodega Bay, California 94923, USA.
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Chen T, Villeneuve TS, Garant KA, Amons R, MacRae TH. Functional characterization of artemin, a ferritin homolog synthesized in Artemia embryos during encystment and diapause. FEBS J 2007; 274:1093-101. [PMID: 17257268 DOI: 10.1111/j.1742-4658.2007.05659.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Oviparously developing embryos of the crustacean Artemia franciscana encyst and enter diapause, exhibiting a level of stress tolerance seldom seen in metazoans. The extraordinary stress resistance of encysted Artemia embryos is thought to depend in part on the regulated synthesis of artemin, a ferritin superfamily member. The objective of this study was to better understand artemin function, and to this end the protein was synthesized in Escherichia coli and purified to apparent homogeneity. Purified artemin consisted of oligomers approximately 700 kDa in molecular mass that dissociated into monomers and a small number of dimers upon SDS/PAGE. Artemin inhibited heat-induced aggregation of citrate synthase in vitro, an activity characteristic of molecular chaperones and shown here to be shared by apoferritin and ferritin. This is the first report that apoferritin/ferritin may protect cells from stress other than by iron sequestration. Stably transfected mammalian cells synthesizing artemin were more resistant to heat and H(2)O(2) than were cells transfected with vector only, actions also shared by molecular chaperones such as the small heat shock proteins. The data indicate that artemin is a structurally modified ferritin arising either from a common ancestor gene or by duplication of the ferritin gene. Divergence, including acquisition of a C-terminal peptide extension and ferroxidase center modification, eliminated iron sequestration, but chaperone activity was retained. Therefore, because artemin accumulates abundantly during development, it has the potential to protect embryos from stress during encystment and diapause without adversely affecting iron metabolism.
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Affiliation(s)
- Tao Chen
- Department of Biology, Dalhousie University, Halifax, NS, Canada
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Clegg JS, Campagna V. Comparisons of stress proteins and soluble carbohydrate in encysted embryos of Artemia franciscana and two species of Parartemia. Comp Biochem Physiol B Biochem Mol Biol 2006; 145:119-25. [PMID: 16914339 DOI: 10.1016/j.cbpb.2006.04.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2006] [Revised: 04/13/2006] [Accepted: 04/20/2006] [Indexed: 11/28/2022]
Abstract
We compared stress proteins (p26, artemin, hsp70) and alcohol-soluble carbohydrates (ASC) in cysts of Artemia franciscana and two as yet un-named species populations of Parartemia, the brine shrimp endemic to Australia. The small stress proteins and molecular chaperones, p26 and artemin, previously thought to be restricted to Artemia, and present in very large amounts in its encysted embryos (cysts), were also detected by western blotting in Parartemia cysts, even though roughly 85-100 million years have passed since these genera diverged. We interpret this finding as further evidence for the adaptive importance of these proteins in coping with the severe stresses these encysted embryos endure. As expected, hsp70 was present in all three groups of cysts, but apparently at somewhat lower concentrations in those of Parartemia. Based on measurements of ASC we propose that the disaccharide trehalose, critical for desiccation tolerance in many animal cells, has probably also been maintained in the metabolic repertoire of Parartemia whose cysts have well developed tolerance to severe desiccation.
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Affiliation(s)
- James S Clegg
- Bodega Marine Laboratory and Section of Molecular and Cellular Biology, University of California, Davis, Bodega Bay, CA 94923, USA.
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Tanguay JA, Reyes RC, Clegg JS. Habitat diversity and adaptation to environmental stress in encysted embryos of the crustaceanArtemia. J Biosci 2004; 29:489-501. [PMID: 15625404 DOI: 10.1007/bf02712121] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Encysted embryos (cysts) of the brine shrimp, Artemia, provide excellent opportunities for the study of biochemical and biophysical adaptation to extremes of environmental stress in animals. Among other virtues, this organism is found in a wide variety of hypersaline habitats, ranging from deserts, to tropics, to mountains. One adaptation implicated in the ecological success of Artemia is p26, a small heat shock protein that previous evidence indicates plays the role of a molecular chaperone in these embryos. We add to that evidence here. We summarize recently published work on thermal tolerance and stress protein levels in embryos from the San Francisco Bay (SFB) of California inoculated into experimental ponds in southern Vietnam where water temperatures are much higher. New results on the relative contents of three stress proteins (hsp70, artemin and p26) will be presented along with data on cysts of A. tibetiana collected from the high plateau of Tibet about 4.5 km above sea level. Unpublished results on the stress protein artemin are discussed briefly in the context of this paper, and its potential role as an RNA chaperone. Interestingly, we show that the substantial tolerance of A. franciscana embryos to ultraviolet (UV) light does not seem to result from intracellular biochemistry but, rather, from their surrounding thick shell, a biophysical adaptation of considerable importance since these embryos receive heavy doses of UV in nature.
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Affiliation(s)
- Joshua A Tanguay
- Section of Molecular and Cellular Biology and the Bodega Marine Laboratory, University of California (Davis), Bodega Bay, California 94923, USA
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Warner AH, Brunet RT, MacRae TH, Clegg JS. Artemin is an RNA-binding protein with high thermal stability and potential RNA chaperone activity. Arch Biochem Biophys 2004; 424:189-200. [PMID: 15047191 DOI: 10.1016/j.abb.2004.02.022] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2003] [Revised: 02/18/2004] [Indexed: 10/26/2022]
Abstract
Encysted embryos of the crustacean, Artemia franciscana, are among the most stress-resistant of all multicellular eukaryotes, due in part to massive amounts of p26, a small heat shock protein, that acts as a molecular chaperone. These embryos contain equally large amounts of another protein called artemin, of previously unknown function, that we report on here. Its thermal stability allows large-scale purification in about a day, using ammonium sulfate fractionation and incubation at 70 degrees C for 7 min, followed by gel filtration. The latter yields an artemin-RNA complex from which the pure protein, apo-artemin, was obtained by anion-exchange chromatography. We evaluated the possibility that artemin acts as a molecular chaperone for proteins, but obtained no evidence for that in vitro. The association of RNA with apo-artemin occurs at high temperatures and, although it is not yet clear whether artemin has a specific role as an RNA chaperone, it does bind non-polyadenylated RNAs which are then translated in vitro. Artemin-RNA is thermostable, some molecules resisting destruction after 30 min at 90 degrees C. The first order rate constant for denaturation and aggregation of artemin-RNA at 85 degrees C is 8.5 x 10(-3)min(-1), which compares well with other thermostable proteins of similar size ( approximately 500 kDa) such as the ferritins with which artemin has amino acid sequence similarity. The amount of artemin extracted from embryos that had been stored dry, under laboratory conditions, since 1951 is comparable to the amount in contemporary embryos, indicating its stability in situ, and supporting the in vitro heating studies.
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Affiliation(s)
- A H Warner
- Department of Biological Sciences, University of Windsor, Windsor, Ont., Canada N9B 3P4
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Clegg JS, Jackson SA, Sorgeloos P. Thermal resistance, developmental rate and heat shock proteins in Artemia franciscana, from San Francisco Bay and southern Vietnam. JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY 2000; 252:85-96. [PMID: 10962067 DOI: 10.1016/s0022-0981(00)00239-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Cysts (encysted gastrula embryos) of Artemia franciscana collected from salterns in San Francisco Bay, California, USA (SF) were inoculated into much warmer growth ponds in the Mekong Delta region of Vietnam (V) in 1996. V adults arising directly from these cysts during 17 April to 15 May produced their own cysts, which were collected, processed and stored until shipped to the USA for study. Adults grown in the laboratory from SF cysts (those used for the inoculation) were less resistant to high temperature than adults cultured from V cysts. V cysts produced heat-resistant adults, even though cultured under the same laboratory conditions as SF animals, at much lower temperatures than they ever experienced in Vietnam. Differences in thermal performance between SF and V adults were retained in the second generation, cultured from cysts produced in the laboratory by first generation adults, suggesting a genetic basis for the better heat resistance of V adults. We propose that the operation of natural selection in the Vietnam growth ponds produced adults with improved thermal tolerance, and that the basis for this tolerance was incorporated into the developmental program of their cysts. Surprisingly, differences in heat resistance of laboratory reared animals were not reflected in constitutive levels of the hsp70 family which were similar in first generation SF and V adults. A conditioning heat shock (HS, 37 degrees C, 30 min) led to the same level of induced thermotolerance in SF and V first generation adults when evaluated 24 h post-HS. Levels of hsp70 were also up-regulated at that time, but to about the same extent in SF and V adults. Developmental rates of SF cysts used for the inoculation were faster than those of cysts produced in Vietnam when both were incubated at 21+/-1 degrees C, suggesting that V cysts have become adapted to develop at higher temperatures.
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Affiliation(s)
- JS Clegg
- Bodega Marine Laboratory, University of California (Davis), 94923, Bodega Bay, CA, USA
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Heise T, Nath A, Jungermann K, Christ B. Purification of a RNA-binding protein from rat liver. Identification as ferritin L chain and determination of the RNA/protein binding characteristics. J Biol Chem 1997; 272:20222-9. [PMID: 9242700 DOI: 10.1074/jbc.272.32.20222] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
In cultured rat hepatocytes the degradation of phosphoenolpyruvate carboxykinase mRNA might be regulated by protein(s), which by binding to the mRNA alter its stability. The 3'-untranslated region of phosphoenolpyruvate carboxykinase mRNA as a potential target was used to select RNA-binding protein(s) from rat liver by the use of gel retardation assays. A cytosolic protein was isolated, which bound to the phosphoenolpyruvate carboxykinase mRNA 3'-untranslated region and other in vitro synthesized RNAs. The protein was purified to homogeneity; it had an apparent molecular mass of 400 kDa and consisted of identical subunits with an apparent size of 24.5 kDa. Sequence analysis of a tryptic peptide from the 24.5-kDa protein revealed its identity with rat ferritin light chain. Binding of ferritin to RNA was abolished after phosphorylation with cAMP-dependent protein kinase and was augmented after dephosphorylation with alkaline phosphatase. Weak binding was observed in extracts from okadaic acid-treated cultured hepatocytes compared with untreated cells. Preincubation of ferritin with an anti-phosphoserine or an anti-phosphothreonine antibody attenuated binding to RNA, while an anti-phosphotyrosine antibody generated a supershift indicating that phosphoserine and phosphothreonine but not phosphotyrosine residues were in close proximity to the RNA-binding region. Ferritin is the iron storage protein in the liver. Binding of ferritin to RNA was diminished in the presence of increasing iron concentrations, whereas the iron chelator desferal was without effect. It is concluded that ferritin might function as RNA-binding protein and that it may have important functions in the general regulation of cellular RNA metabolism.
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Affiliation(s)
- T Heise
- Institut für Biochemie und Molekulare Zellbiologie, Georg-August-Universität Göttingen, Humboldtallee 23, 37073 Göttingen, Germany
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Clegg JS, Jackson SA. Aerobic heat shock activates trehalose synthesis in embryos of Artemia franciscana. FEBS Lett 1992; 303:45-7. [PMID: 1592115 DOI: 10.1016/0014-5793(92)80474-u] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Encysted embryos (cysts) of the brine shrimp, Artemia franciscana, contain large amounts of trehalose which they use as a major substrate for energy metabolism and biosynthesis for development under aerobic conditions at 25 degrees C. When cysts are placed at 42 degrees C (heat shock) these pathways stop, and the cysts re-synthesize the trehalose that was utilized during the previous incubation at 25 degrees C. Glycogen and glycerol, produced from trehalose at 25 degrees C, appear to be substrates for trehalose synthesis during heat shock. Anoxia prevents trehalose synthesis in cysts undergoing heat shock. These results are consistent with the view that trehalose may play a protective role in cells exposed to heat shock, and other environmental insults, in addition to being a storage form of energy and organic carbon for development.
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Affiliation(s)
- J S Clegg
- University of California, Davis Bodega Marine Laboratory, Bodega Bay 94923
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15
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De Graaf J, Amons R, Möller W. The primary structure of artemin from Artemia cysts. EUROPEAN JOURNAL OF BIOCHEMISTRY 1990; 193:737-50. [PMID: 2249691 DOI: 10.1111/j.1432-1033.1990.tb19394.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The primary structure of artemin, a major protein isolated from Artemia cysts, has been determined by direct Edman degradation of the purified protein. The amino-terminal acetylated protein has 229 amino acid residues and a high content of histidine and cysteine/cystine. A search in the GenBank Data Base at Los Alamos, using the FASTA program [Pearson, W. R. & Lipman, D. J. (1988) Proc. Natl. Acad. Sci. USA 85, 2444-2448] revealed a limited but unmistakable similarity to ferritin from vertebrates.
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Affiliation(s)
- J De Graaf
- Department of Medical Biochemistry, State University of Leiden, The Netherlands
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Miller D, McLennan AG. The heat shock response of the cryptobiotic brine shrimp Artemia — II. Heat shock proteins. J Therm Biol 1988. [DOI: 10.1016/0306-4565(88)90023-x] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Janssen GM, Möller W. Elongation factor 1 beta gamma from Artemia. Purification and properties of its subunits. EUROPEAN JOURNAL OF BIOCHEMISTRY 1988; 171:119-29. [PMID: 3276514 DOI: 10.1111/j.1432-1033.1988.tb13766.x] [Citation(s) in RCA: 101] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The guanine nucleotide exchange factor, elongation factor 1 beta gamma (EF-1 beta gamma) has been purified from Artemia cysts using an improved method. The protein consists of two distinct polypeptides with relative molecular masses of 26,000 (EF-1 beta) and 46,000 (EF-1 gamma). A nucleoside diphosphate phosphotransferase activity often found in EF-1 beta gamma preparations has been completely separated from the actual guanine nucleotide exchange stimulatory activity of EF-1 beta gamma, thus indicating that nucleotide diphosphate phosphotransferase is not an intrinsic property of EF-1 beta. Both EF-1 beta gamma and EF-1 beta have been shown to stimulate the following three reactions to a comparable degree: (a) exchange of GDP bound to EF-1 alpha with exogenous GDP; (b) EF-1 alpha-dependent binding of Phe-tRNA to ribosomes; (c) poly(U)-dependent poly(phenylalanine) synthesis. However, a significantly higher nucleotide exchange rate was observed in the presence of EF-1 beta gamma compared to EF-1 beta alone. Concerning elongation factor 1 gamma (EF-1 gamma) the following observations were made. In contrast to EF-1 beta, pure EF-1 gamma is rather insoluble in aqueous buffers, but the tendency to precipitate can be partially suppressed by the addition of detergents. In particular, EF-1 gamma partitions solely into the detergent phase of Triton X-114 solutions. EF-1 gamma is also more susceptible to spontaneous, specific fragmentation. It is remarkably that about 5% of the cellular pool of EF-1 beta gamma was found to be present in membrane fractions, under conditions where no EF-1 alpha was detectable in these fractions. Furthermore it was noted that EF-1 beta gamma copurified strongly with tubulin on DEAE-cellulose. Moreover, it was observed that from a mixture of EF-1 beta gamma and tubulin, EF-1 gamma coprecipitates with tubulin using a non-denaturating immunoprecipitation technique. These findings suggest that EF-1 gamma has a hydrophobic domain and interacts with membrane and cytoskeleton structures in the cell.
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Affiliation(s)
- G M Janssen
- Laboratory for Medical Biochemistry, State University of Leiden, The Netherlands
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18
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Thoen C, Van Hove L, Slegers H. Identification of the substrates of the casein kinase II associated with non-polysomal messenger ribonucleoproteins of A. salina cryptobiotic embryos. Mol Biol Rep 1986; 11:69-75. [PMID: 3461261 DOI: 10.1007/bf00364816] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The association of a protein kinase with cytoplasmic non-polysomal messenger ribonucleoproteins is demonstrated by chromatography on oligo(dT)-cellulose and sucrose gradient centrifugation. The cAMP-independent enzyme is inhibited by caffeine and poly(L)-glutamic acid and is classified as a casein kinase II. Among the exogenous proteins initiation factor eIF2 is the best substrate and is 7.8 times more efficiently phosphorylated than casein. Endogenous mRNP protein substrates have a Mr of 125 000, 65 000, 38 000, 26 000 and 23 500. The main phosphate acceptor is the Mr 38 000 poly(A)-binding protein. Dephosphorylation of the poly(A)-binding protein by protein phosphatases decreases its RNA binding property. The effect of phosphorylation-dephosphorylation of mRNP proteins on the initiation of protein synthesis is discussed.
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Ribosome-associated cyclic nucleotide-independent protein kinase of Artemia salina cryptobiotic gastrulae. BIOCHIMICA ET BIOPHYSICA ACTA 1985; 825:268-79. [PMID: 2990557 DOI: 10.1016/0167-4781(85)90014-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
An extra-ribosomal cAMP-independent protein kinase from cryptobiotic embryos of Artemia salina has been purified to near homogeneity by gel filtration on Bio-Gel A-0.5 m, ion-exchange chromatography on DEAE-cellulose and phosphocellulose P11 and affinity chromatography on casein-Sepharose 4B and ATP-agarose. The enzymatic activity has a broad optimum at pH 7-8. Maximal activity is obtained in the presence of 5-6 mM MgCl2. The activity is inhibited by Mn2+, Ca2+ and K+. The enzyme has an Mr of 127 000, utilizes both ATP and GTP as phosphoryl donors and is completely inhibited by heparin and poly(L-glutamic acid). According to its properties, the enzyme can be classified as a casein kinase type II. Although the enzyme is associated with ribosomes, ribosomal proteins are not among the main substrates. The kinase is able to phosphorylate both the alpha and the beta subunits of initiation factor eIF2 using ATP or GTP as phosphoryl donors. The function of phosphorylation in the initiation of protein synthesis is discussed.
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20
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Sastre L, Sebastián J. Developmental changes in poly(A) polymerase activity in Artemia. EUROPEAN JOURNAL OF BIOCHEMISTRY 1983; 135:69-74. [PMID: 6309518 DOI: 10.1111/j.1432-1033.1983.tb07618.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The levels of poly(A) polymerase activity have been determined during Artemia early development. Poly(A) polymerase activity increases steadily during postgastrular embryonic development reaching a maximum shortly after hatching. The rise of poly(A) polymerase is concomitant with an increase in poly(A) content and with a change in the subcellular distribution of the enzyme activity, the major increase corresponding to the nuclear fraction. Only one isoenzyme of poly(A) polymerase has been identified in Artemia embryos and nauplii despite changes in enzyme levels and subcellular changes during early development. Poly(A) polymerase is not associated with the cytoplasmic poly(A)-containing ribonucleoprotein particles stored in Artemia dormant embryos.
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21
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De Herdt E, De Voeght F, Clauwaert J, Kondo M, Slegers H. A cryptobiosis-specific 19S protein complex of Artemia salina gastrulae. Biochem J 1981; 194:9-17. [PMID: 7305995 PMCID: PMC1162711 DOI: 10.1042/bj1940009] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The postribosomal supernatant of Artemia salina cryptobiotic embryos contains a large quantity of a 19S protein complex. An amount of 3.6 mg/g of cysts is measured by immunoprecipitation with anti-(19S protein complex) antibody. The quantity of this complex decreases during further development to nauplius larvae to only 15% of the quantity present in cryptobiotic embryos. The complex was no longer detectable after 7 days of growth. The 27000-Mr protein subunit of the 19S complex is not synthesized by mRNA isolated from cryptobiotic embryos. The cryptobiosis-specific complex has Mr 573000 and 610000 as calculated from light-scattering and sedimentation-diffusion measurements respectively. The 19S homocomplex contains 20-23 27000-Mr proteins and has no function in the translation of homologous mRNA. From hydrodynamic data a hydration of 1.25 g of water/g of protein is calculated. The abundant presence of the 19S protein complex in cryptobiotic embryos and the absence of synthesis during development to nauplius larvae indicate a functional role during the cryptobiotic process in early embryogenesis. A role in maintaining the water content of the cytoplasm above a critical threshold during desiccation is suggested.
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Vincent A, Civelli O, Maundrell K, Scherrer K. Identification and characterization of the translationally repressed cytoplasmic globin messenger-ribonucleoprotein particles from duck erythroblasts. EUROPEAN JOURNAL OF BIOCHEMISTRY 1980; 112:617-33. [PMID: 7460940 DOI: 10.1111/j.1432-1033.1980.tb06127.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Globin messenger ribonucleoprotein (mRNP) particles which have been isolated from duck erythroblast post-polyribosomal supernatant are translationally inactive in vivo and in vitro but contain translatable mRNA active after deproteinisation. They were characterized following purification by successive sucrose gradient sedimentation in a buffer containing 0.05 M KCl. The complex, which sediments homogeneously at about 20 S, has a density of 1.39 g/cm3 and thus consists of four parts protein to one part RNA; 40% of this RNA is globin mRNA and no other mRNA could be detected. Sedimentation of the purified globin mRNP on sucrose gradients in 0.5 M KCl produced four components while polyacrylamide gel electrophoresis in non-denaturing conditions and in the presence of EDTA resulted in the separation of three components. Hybridization to globin cDNA and translation in vitro of the RNA extracted from these subparticles revealed the existence of two core particles containing globin mRNA with nominal sedimentation coefficients of 13 S and 16 S. Analysis of the protein components of the isolated sub-complexes by dodecyl sulfate and bidimensional gel electrophoresis indicated a very characteristic protein composition for each of these complexes. The 16-S and 13-S globin mRNPs differed essentially by the presence in the 13-S mRNP only of a group of major polypeptides. Of the other two sub-complexes, one consisted of 90% small RNA in the 4-S range; the second sedimented ahead of the globin mRNP core particles at about 19S and consisted of a very characteristic set of about 14 polypeptides. The polyribosomal 73000-Mr poly(A)-binding protein was not detected in the purified free globin mRNP although the mRNA in the untranslatable particle is polyadenylated. The presence in the cytoplasm of duck erythroblasts of two forms of untranslated globin messenger ribonucleoprotein particles, distinct in their protein composition from polyribosomal globin mRNP, suggests that they may have a specific role in the regulation of translation of globin mRNA.
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A single-stranded nucleic acid-binding protein from Artemia salina. I. Purification and characterization. J Biol Chem 1980. [DOI: 10.1016/s0021-9258(18)43763-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Roobol K, Vianden I, Möller W. Aggregation of eucaryotic elongation factor eEF-Ts and its isolation by means of hydrophobic adsorption chromatography. FEBS Lett 1980; 111:136-42. [PMID: 6898478 DOI: 10.1016/0014-5793(80)80778-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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