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1.
Ding Wen Wu John G. Duman 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1991,161(3):279-283
Summary Purified antifreeze proteins (AFPs) from the larvae of the beetle Dendroides canadensis do not produce the high levels of antifreeze activity seen in the hemolymph of overwintering larvae, even when the purified AFPs are assayed at very high concentrations. However, addition of certain proteins or agar (at concentrations sufficiently low that the gel state does not result) to the Dendroides AFP resulted in a 2–3-fold increase in activity. A 70-kDa protein with AFP-activating capabilities was purified from Dendroides larvae. Addition of this endogenous activator protein to a 4 mg·ml-1 solution of AFP increased the activity of the AFPs to values comparable to those of the hemolymph of overwintering larvae. Data derived from a modified immunoblot technique demonstrate that the activators bind to the AFP, or vice versa. Formation of this association must allow the AFP to block ice crystal growth by binding to the surface of potential seed crystals in the normal fashion. However, because the AFP-activator complex is much larger than the AFP alone, the complex probably blocks a greater surface area of the crystal and is thus a more efficient antifreeze.Abbreviations
AFP
antifreeze protein
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BSA
bovine serum albumine
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DEAE
diethylaminoethyl
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Ig
immunoglubolin
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LPIN
lipoprotein ice nucleator
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PIN
protein ice nucleator
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SDS
sodium dodecyl sulfate
-
PAGE
polyacrylamide gel electrophoresis
-
TH
thermal hysteresis 相似文献
2.
3.
Antifreeze proteins in Alaskan insects and spiders 总被引:13,自引:0,他引:13
Duman JG Bennett V Sformo T Hochstrasser R Barnes BM 《Journal of insect physiology》2004,50(4):259-266
Prior to this study, antifreeze proteins (AFPs) had not been identified in terrestrial arthropods from the Arctic or anywhere in Alaska. The hemolymph of 75 species of insects and six spiders from interior and arctic Alaska were screened for thermal hysteresis (a difference between the freezing and melting points), characteristic of the presence of AFPs. Eighteen species of insects and three spiders were shown to have AFPs. Ten of the insects with AFPs were beetles including the first species from the families Chrysomelidae, Pythidae, Silphidae and Carabidae. In addition, the first Neuropteran to have AFPs was identified, the lacewing Hemerobius simulans together with the second and third Diptera (the first Tipulids) and the second and third Hemiptera, the stinkbug Elasmostethus interstinctus (the first Pentatomid), and the water strider Limnoporus dissortis (the first Gerrid). Prior to this study, 33 species of insects and three spiders had been reported to have AFPs. Most AFP-producing terrestrial arthropods are freeze avoiding, and the AFPs function to prevent freezing. However, some of the AFP- producing insects identified in this study are known to be freeze tolerant (able to survive freezing) to very low temperatures (-40 to -70 degrees C). 相似文献
4.
Päivi L. H. Rinne Päivi L. M. Kaikuranta Linus H. W. van der Plas Chris van der Schoot 《Planta》1999,209(4):377-388
Dehydrins accumulate in various plant tissues during dehydration. Their physiological role is not well understood, but it
is commonly assumed that they assist cells in tolerating dehydration. Since in perennials the ability of the shoot apex to
withstand dehydration is pivotal for survival through winter, we investigated if and how dehydrins may be involved. A first
step in assessing such a role is the identification of their subcellular location. We therefore mapped the location of dehydrin
homologues, abscisic acid-responsive (RAB 16-like) polypeptides, in the apex of birch (Betula pubescens Ehrh.). In non-cold-acclimated plants a single low-abundant RAB 16-member (a 33-kDa polypeptide) was produced, and localized
in the cytoplasm only. During cold acclimation two additional members were produced (24 and 30 kDa) and accumulated in nuclei,
storage protein bodies and starch-rich amyloplasts. Western blots of proteins isolated from purified starch granules and from
protein bodies revealed the presence of the 24-kDa dehydrin. Since starch and protein reserves are gradually consumed during
winter, serving cell maintenance, starch- and protein-degrading enzymes must remain locally active. We therefore investigated
the hypothesis that dehydrins might create local pools of water in otherwise dehydrated cells, thereby maintaining enzyme
function. In agreement with our hypothesis, enzyme assays showed that under conditions of low water activity a partially purified
dehydrin fraction was able to improve the activity of α-amylase (EC 3.2.1.1.) relative to fractions from which dehydrin was
removed by immunoprecipitation. The results confirm the general belief that dehydrins serve desiccation tolerance, and suggest
that a major function is to rescue the metabolic processes that are required for survival and re-growth.
Received: 12 September 1998 / Accepted: 19 April 1999 相似文献
5.
小麦耐逆基因-TaLEA3的克隆及在酵母中的功能分析 总被引:10,自引:0,他引:10
LEA蛋白(late-embryogenesis-abundant protein),是指胚胎发生后期种子中大量积累的一类蛋白质,它广泛存在于高等植物中,且受发育阶段、脱落酸(ABA)和脱水信号的调节,其中第3组LEA蛋白与作物耐逆性密切相关。通过RT-PCR从小麦中克隆了一个新的第3组LEA蛋白基因,TaLEA3。该蛋白主要定位于细胞质。TaLEA3的表达受高盐、低温和外源激素ABA的诱导,根中表达量一般高于叶中,且在不同胁迫下该基因表达模式存在差异。在所检测的一对同核异质小麦品种中,该基因的表达与耐旱性呈正相关。TaLEA3在酵母中过量表达,改善了酵母在离子和渗透胁迫下的生长状态或提高了存活率。 相似文献
6.
Molecular characterization and sequencing of antifreeze proteins from larvae of the beetle Dendroides canadensis 总被引:4,自引:0,他引:4
J. G. Duman N. Li D. Verleye F. W. Goetz D. W. Wu C. A. Andorfer T. Benjamin D. C. Parmelee 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1998,168(3):225-232
The deduced amino acid sequences of antifreeze proteins (AFPs) from larvae of the beetle Dendroides canadensis were determined from both complementary DNAs (cDNAs) and from peptide sequencing. These consisted of proteins with a 25-residue
signal peptide and mature proteins 83 (Dendroides antifreeze protein; DAFP-1) or 84 (DAFP-2) amino acids in length which differed at only two positions. Peptide sequencing
yielded sequences which overlapped exactly with those of the deduced cDNA sequences of DAFP-1 and DAFP-2, while the partial
sequence of another AFP (DAFP-3) matched 21 of 28 residues. Seven 12- or 13-mer repeating units are present in these antifreeze
proteins with a consensus sequence consisting of: Cys-Thr-X3-Ser-X5-X6-Cys-X8-X9-Ala-X11-Thr-X13, where X3 and X11 tend toward charged residues, X5 tends toward threonine or serine, X6 toward asparagine or aspartate, X9 toward asparagine or lysine, and X13 toward alanine in the 13-mers. The most interesting feature of these proteins is that throughout the length of the mature
antifreeze proteins every sixth residue is a cysteine. These sequences are not similar to any of the known fish AFPs, but
they are similar to AFPs from the beetle Tenebrio molitor.
Accepted: 14 November 1997 相似文献
7.
We examined Hsc70 in gill, liver and caudal fin from coho salmon ( Oncorhynchus kisutch ) before (ambient, ~12 °C) and after a sublethal heat shock of 25 °C for 1 h. Increased levels were observed for at least 48 h in all three tissues. Attempts to demonstrate isoforms of this heat-shock protein were not successful using four different antibodies. However, one of these antibodies recognized isoforms in brine shrimp and oysters, two organisms in which the heat-shock response has been well characterized. Extracts of those organisms and coho salmon tissues were run on the same gels and evaluated on the same Western blots, at the same time. We believe that our results provide a reliable account of Hsc70 in these fish under these conditions. Limited experiments showed that induced thermotolerance was achieved in these coho salmon, lasting for about 1 week after the sublethal heat shock. These data suggest that increased levels of Hsc70 are correlated with induced thermotolerance in these fish. 相似文献
8.
9.
We isolated and sequenced Ha hsp 17.9, a DNA complementary (cDNA) of dry-seed stored mRNA that encodes a low-molecular-weight heat-shock protein (LMW HSP). Sequence analysis identified Ha hsp17.9, and the previously reported Ha hsp17.6, as cDNAs encoding proteins (HSP17.6 and HSP17.9) which belong to different families of cytoplasmic LMW HSPs. Using specific antibodies we observed differential expression of both proteins during zygotic embryogenesis under controlled environment, and a remarkable persistence of these LMW HSPs during germination. Immuno-blot analysis of HSP17.9 proteins in two-dimensional gels revealed that the polypeptides expressed in embryos were indistinguishable from LMW HSPs expressed in vegetative tissues in response to water deficit; but they appeared different from homologeous proteins expressed in response to thermal-stress. Tissue-print immunolocalization experiments showed that HSP17.9 and HSP17.6 were homogeneously distributed in every tissue of desiccation-tolerant dry seeds and young seedlings under non-stress conditions. These results demonstrate developmental regulation of specific, cytoplasmic, plant LMW HSPs, suggesting also their involvement in water-stress tolerance. 相似文献
10.
Chatelain E Hundertmark M Leprince O Le Gall S Satour P Deligny-Penninck S Rogniaux H Buitink J 《Plant, cell & environment》2012,35(8):1440-1455
Developing seeds accumulate late embryogenesis abundant (LEA) proteins, a family of intrinsically disordered and hydrophilic proteins that confer cellular protection upon stress. Many different LEA proteins exist in seeds, but their relative contribution to seed desiccation tolerance or longevity (duration of survival) is not yet investigated. To address this, a reference map of LEA proteins was established by proteomics on a hydrophilic protein fraction from mature Medicago truncatula seeds and identified 35 polypeptides encoded by 16 LEA genes. Spatial and temporal expression profiles of the LEA polypeptides were obtained during the long maturation phase during which desiccation tolerance and longevity are sequentially acquired until pod abscission and final maturation drying occurs. Five LEA polypeptides, representing 6% of the total LEA intensity, accumulated upon acquisition of desiccation tolerance. The gradual 30-fold increase in longevity correlated with the accumulation of four LEA polypeptides, representing 35% of LEA in mature seeds, and with two chaperone-related polypeptides. The majority of LEA polypeptides increased around pod abscission during final maturation drying. The differential accumulation profiles of the LEA polypeptides suggest different roles in seed physiology, with a small subset of LEA and other proteins with chaperone-like functions correlating with desiccation tolerance and longevity. 相似文献
11.
12.
Identification and characterization of a heat-induced isoform of aldolase in oat chloroplast 总被引:1,自引:0,他引:1
An analysis of protein synthesis at elevated temperatures in oat (Avena sativa) leaves revealed a heat-induced 44 kDa polypeptide. A cDNA library of heat-treated leaves was constructed and screened with specific antibodies raised against this 44 kDa polypeptide. A clone encoding the 44 kDa protein was identified as a form of the chloroplast-localized fructose-bisphosphate aldolase (EC 4.1.2.13). Northern and western blot analyses indicated heat-induced accumulation of the chloroplast aldolase isoform at both the RNA and protein level. Heat inducibility was restricted to the chloroplastic form of the enzyme, and was not observed for the cytoplasmic aldolase. The heat-induced isoform co-purified with thykaloid fractions, as confirmed by immunoassay and activity analyses. However, when thylakoid membranes were treated with proteinase K, the aldolase isoform completely disappeared, suggesting that this enzyme is not embedded but rather tends to adhere to the chloroplast membranes. Immunoblot analysis of other plant species revealed similar heat induction of thykaloid-associated aldolase homologues, suggesting the possible existence of a universal control mechanism for this enzyme's heat tolerance 相似文献
13.
水母雪莲愈伤组织和悬浮培养细胞的抗冻性研究 总被引:12,自引:0,他引:12
水母雪莲(Saussurea meduasa Maxim)是典型的高山雪线植物。本文研究了其愈伤组织及悬浮细胞的培养过程,并对其抗寒性做了初步研究,研究结果表明,水母雪莲愈伤组织和悬浮培养细胞分别可抵抗-6.5℃、-7.5℃的冰冻低温胁迫,水母雪莲愈伤组织细胞内丰富的蛋白质和淀粉粒多糖构成其较强抗冻能力的物质基础,低温锻炼后,悬浮细胞分泌蛋白中有新的多肽(76,48,27.5,19.5kD)合成,而33,51kD两条多肽合成增强,悬浮细胞抗冻能力的提高同蛋白质合成的增强是一致的。 相似文献
14.
Water loss either by desiccation or freezing causes multiple forms of cellular damage. The encysted embryos (cysts) of the crustacean Artemia franciscana have several molecular mechanisms to enable anhydrobiosis—life without water—during diapause. To better understand how cysts survive reduced hydration, group 1 late embryogenesis abundant (LEA) proteins, hydrophilic unstructured proteins that accumulate in the stress-tolerant cysts of A. franciscana, were knocked down using RNA interference (RNAi). Embryos lacking group 1 LEA proteins showed significantly lower survival than control embryos after desiccation and freezing, or freezing alone, demonstrating a role for group 1 LEA proteins in A. franciscana tolerance of low water conditions. In contrast, regardless of group 1 LEA protein presence, cysts responded similarly to hydrogen peroxide (H2O2) exposure, indicating little to no function for these proteins in diapause termination. This is the first in vivo study of group 1 LEA proteins in an animal and it contributes to the fundamental understanding of these proteins. Knowing how LEA proteins protect A. franciscana cysts from desiccation and freezing may have applied significance in aquaculture, where Artemia is an important feed source, and in the cryopreservation of cells for therapeutic applications. 相似文献
15.
Differential accumulation of two glycine-rich proteins during cold-acclimation alfalfa 总被引:9,自引:0,他引:9
Ferullo Jean-Marc Vézina Louis-P. Rail Jimmy Laberge Serge Nadeau Paul Castonguay Yves 《Plant molecular biology》1997,33(4):625-633
16.
曾卫军;原慧;覃建兵 《植物研究》2012,32(6):744-749
小分子热激蛋白是植物受到热胁迫后的主要表达产物之一,与植物细胞耐热有密切关系。该研究发现,拟南芥小分子热激蛋白基因AtsHsp17.6-CⅠ和AtsHsp17.6-CⅡ 除热激之外,重金属离子Ni+、Pb2+、Cu2+、Zn2+和Al3+均能诱导这2个热激蛋白基因的表达;氧化胁迫和渗透胁迫同样也能诱导它们表达。该研究将由CaMV35S启动子驱动的这2个小分子热激蛋白基因导入拟南芥,RT-PCR分析表明,2个小分子热激蛋白基因在转基因植物中呈现组成型表达。实验结果表明,组成型表达小分子热激蛋白基因AtsHsp17.6-CⅠ的转基因植物表现出对6 μmol·L-1 Cd2+胁迫、0.4% NaCl胁迫的耐受性。研究表明,这2个小分子热激蛋白基因可能参与着多种抗逆途径,推测其能够减轻或抵抗逆境胁迫引起的伤害并对其进行修复。 相似文献
17.
质膜转运蛋白及其与植物耐盐性关系研究进展 总被引:13,自引:0,他引:13
植物细胞质膜有两种主要功能:⑴溶质运输(进出细胞),溶质运输主要由转运蛋白完成;⑵信号传导,即接收信号并引发细胞生理生化响应。盐分过多对植物的伤害主要是离子毒害。质膜转运蛋白活性环境变化能做现迅速响应。本文简要叙述了植物细胞质膜转运蛋白类型、分子特性、生理功能及其活性调节。介绍了植物细胞质膜H^+-ATPase、质膜氧化还原系统、质膜离子载体和离子通道对盐胁迫的响应及其这些响应与植物耐盐性之间的关 相似文献
18.
John G. Duman Lisa G. Neven John M. Beals Kenneth R. Olson Francis J. Castellino 《Journal of insect physiology》1985,31(1):1-8
The terrestrial overwintering larvae of the cranefly Tipula trivittata were freeze tolerant (able to survive the freezing of their extracellular body fluids) throughout the winter and spring of 1982–1983 until they pupated in mid-May. The larvae were most cold tolerant (24 h lower lethal temperatures of ?25 to ?30°C) in late January and early February. Sorbitol, at a maximal concentration of ~0.4 M, was the only polyol determined to be present at high levels and sorbitol accounted for most of the seasonal fluctuation in osmotic concentration. Haemolymph inorganic ion (Na+, K+, Ca2+, Mg2+, Cl?) concentrations did not vary seasonally.The supercooling points of the larvae remained constant at ?6 to ?7°C over the study period because of the presence of haemolymph ice nucleating factors. These ice nucleating factors consist not only of haemolymph proteins, as had been demonstrated previously in other insect species, but also lipoproteins. 相似文献
19.
We recently showed that the chloroplast small heat-shock protein (herein referred to as chlp Hsp24) protects photosystem 2 (PS2) during heat stress, and phenotypic variation in production of chlp Hsp24 is positively related to PS2 thermotolerance. However, the importance of chlp Hsp24 or other Hsps to other aspects of photosynthesis and overall photosynthetic thermotolerance is unknown. To begin investigating this and the importance of genetic variation in Hsp production to photosynthetic thermotolerance, the production of several prominent Hsps and photosynthetic thermotolerance were quantified in nine genotypes of Lycopersicon, and then the relationships between thermotolerance of net photosynthetic rate (P
N) and production of each Hsp were examined. The nine genotypes exhibited wide variation in P
N thermotolerance and production of each of the Hsps examined (chlp Hsp70, Hsp60, and Hsp24, and cytosol Hsp70). No statistically significant relationship was observed between production of chlp Hsp70 and P
N thermotolerance, and only a weak positive relationship between cytosolic Hsp70 and P
N was detected. However, significant positive relationships were observed between production of chlp Hsp24 and Hsp60 and P
N thermotolerance. Hence natural variation in production of chlp Hsp24 and Hsp60 is important in determining variation in photosynthetic thermotolerance. This is perhaps the first evidence that chlp Hsp60 is involved in photosynthetic thermotolerance, and these in vivo results are consistent with previous in vitro results showing that chlp Hsp24 protects PS2 during heat stress. 相似文献
20.
Ding W. Wu John G. Duman Chi-Hing C. Cheng Francis J. Castellino 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1991,161(3):271-278
Summary Four antifreeze proteins (AFPs) were purified from larvae of the beetle Dendroides canadensis. The AFPs are similar in amino acid compositions, having high contents of hydrophilic amino acids (45–55 mol%) and cysteine (16 mol% Cys). Approximately half of the Cys residues form disulfide bridges, and both the disulfide bridges and free sulfhydryls are essential for activity. The N-terminals of the AFPs are blocked. The pH optimum of the AFPs is 7.8, but major loss of activity occurred only at very high pH (12.0). The detergents SDS and Triton X-100 did not inactivate the AFPs. Circular dichroism spectra indicate the presence of both and secondary structures in the AFPs, in addition to a large random structure component.Abbreviations
AFP
antifreeze protein
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CD
circular dichroism
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DTT
dithiothreitol
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HPLC
high pressure liquid chromatography
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PAGE
polyacrylamide gel electrophoresis
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PAS
periodic acid Schiff
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SDS
sodium dodecyl sulfate
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TFA
trifluoroacetic acid 相似文献