scholarly journals Protein homeostasis imprinting across evolution

2020 ◽  
Author(s):  
Thodoris Koutsandreas ◽  
Eric Chevet ◽  
Aristotelis Chatziioannou ◽  
Brice Felden
Keyword(s):  
Life Forms ◽  
Environmental Constraints ◽  
Protein Homeostasis ◽  
Gene Conservation ◽  
Biological Impact ◽  
Protein Biogenesis ◽  
Novel Strategy ◽  
Species Specific ◽  
Shock Proteins ◽  
Rrna Sequences

AbstractThe control of protein homeostasis (a.k.a. proteostasis) is associated with the primary functions of life, and therefore with evolution. However, it is unclear how the cellular proteostasis has evolved to adjust the protein biogenesis needs with environmental constraints. Herein, we describe an approach to evaluate proteostasis during evolution, and show that the proteostasis network (PN) represents a reliable metric to i) deconvolute the life forms into Archaea, Bacteria and Eukaryotes and ii) assess the evolution rates among species, without the need for rRNA sequences. This method for phylogenetic comparison relies on the use of semantic graphs to evaluate PN complexity. This stands as a novel strategy for taxonomic classification, based on the analysis of 94 Eukaryotes, 250 Bacteria and 93 Archaea genome sequences. A functional analysis was used as a powerful phylogenetic tool that echoes with species complexity. It provides information about species divergence and indicates the taxonomic clades that evolved faster than others did. Phyla-specific PN were identified, suggesting that PN complexity correlates with the grade of evolution the species have reached. Individual components, however, such as the heat shock proteins (HSP) do not accurately mark evolution. We analyzed gene conservation, gain or loss that occurred throughout PN evolution, which reveals a dichotomy within the PN conserved parts (e.g. chaperones), but also with species-specific modules. Since the PN is implicated in cell fitness, aging control and the onset of several diseases, it could be used as a metric to tackle gain-of-functions mechanisms and their biological impact.

scholarly journals Testing the potential of pollen assemblages to capture composition, diversity and ecological gradients of surrounding vegetation in two biogeographical regions of southeastern Europe

2021 ◽  
Author(s):  
Maria Papadopoulou ◽  
Ioannis Tsiripidis ◽  
Sampson Panajiotidis ◽  
Georgios Fotiadis ◽  
Daniel Veres ◽  
...  
Keyword(s):  
Vegetation Structure ◽  
Diversity Indices ◽  
Life Forms ◽  
Ecological Gradients ◽  
Vegetation Diversity ◽  
North Central ◽  
Plant Life Forms ◽  
Pollen Diagrams ◽  
Biogeographical Regions ◽  
Species Specific

AbstractDue to the complex relationship between pollen and vegetation, it is not yet clear how pollen diagrams may be interpreted with respect to changes in floristic diversity and only a few studies have hitherto investigated this problem. We compare pollen assemblages from moss samples in two southeastern European forests with the surrounding vegetation to investigate (a) their compositional similarity, (b) the association between their diversity characteristics in both terms of richness and evenness, and (c) the correspondence of the main ecological gradients that can be revealed by them. Two biogeographical regions with different vegetation characteristics, the Pieria mountains (north central Greece) and the slopes of Ciomadul volcano (eastern Romania), were chosen as divergent examples of floristic regions, vegetation structure and landscape openness. Pollen assemblages are efficient in capturing the presence or absence, rather than the abundance in distribution of plants in the surrounding area and this bias increases along with landscape openness and vegetation diversity, which is higher in the Pieria mountains. Pollen assemblages and vegetation correlate better in terms of richness, that is, low order diversity indices. Relatively high correlation, in terms of evenness, could be potentially found in homogenous and species poor ecosystems as for Ciomadul. Composition and diversity of woody, rather than herb, vegetation is better reflected in pollen assemblages of both areas, especially for Pieria where a direct comparison of the two components was feasible, although this depends on the species-specific pollen production and dispersal, the openness of landscape and the overall diversity of vegetation. Gradients revealed by pollen assemblages are highly and significantly correlated with those existing in vegetation. Pollen assemblages may represent the vegetation well in terms of composition, diversity (mainly richness) and ecological gradients, but this potential depends on land use, vegetation structure, biogeographical factors and plant life forms.

scholarly journals Species-specific collaboration of heat shock proteins (Hsp) 70 and 100 in thermotolerance and protein disaggregation

2011 ◽  
Vol 108 (17) ◽  
pp. 6915-6920 ◽  
Author(s):  
M. Miot ◽  
M. Reidy ◽  
S. M. Doyle ◽  
J. R. Hoskins ◽  
D. M. Johnston ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Hsp 70 ◽  
Species Specific ◽  
Shock Proteins

scholarly journals A Comparison of Stage Conversion in the Coccidian Apicomplexans Toxoplasma gondii, Hammondia hammondi, and Neospora caninum

2020 ◽  
Vol 10 ◽  
Author(s):  
Sarah L. Sokol-Borrelli ◽  
Rachel S. Coombs ◽  
Jon P. Boyle
Keyword(s):  
Life Cycle ◽  
Toxoplasma Gondii ◽  
Stress Responses ◽  
Neospora Caninum ◽  
Life Forms ◽  
New Host ◽  
Environmental Signals ◽  
Stage Conversion ◽  
Genetic Components ◽  
Species Specific

Stage conversion is a critical life cycle feature for several Apicomplexan parasites as the ability to switch between life forms is critical for replication, dissemination, pathogenesis and ultimately, transmission to a new host. In order for these developmental transitions to occur, the parasite must first sense changes in their environment, such as the presence of stressors or other environmental signals, and then respond to these signals by initiating global alterations in gene expression. As our understanding of the genetic components required for stage conversion continues to broaden, we can better understand the conserved mechanisms for this process and unique components and their contribution to pathogenesis by comparing stage conversion in multiple closely related species. In this review, we will discuss what is currently known about the mechanisms driving stage conversion in Toxoplasma gondii and its closest relatives Hammondia hammondi and Neospora caninum. Work by us and others has shown that these species have some important differences in the way that they (1) progress through their life cycle and (2) respond to stage conversion initiating stressors. To provide a specific example of species-specific complexities associated with stage conversion, we will discuss our recent published and unpublished work comparing stress responses in T. gondii and H. hammondi.

Infusing Mature Megakaryocytes Into Mice Yields Functional Platelets: Biological and Clinical Implications.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 225-225
Author(s):  
Rudy Fuentes ◽  
Yuhuan Wang ◽  
Jessica Hirsh ◽  
Mortimer Poncz
Keyword(s):  
Half Life ◽  
Positive Control ◽  
Pulmonary Vasculature ◽  
Recipient Mouse ◽  
Actual Process ◽  
Alternative Source ◽  
Marrow Space ◽  
Novel Strategy ◽  
Species Specific ◽  
Cell Fractions

Abstract Abstract 225 Thrombopoiesis, the process by which circulating platelets (plts) arise from megakaryocytes (Megs) remains incompletely understood. Two models had been proposed: (1) release of plts produced from Megs within the marrow space and (2) release of plts by circulating Megs within the pulmonary vasculature. Recently, murine two-photon electron microscopy suggested that the actual process may involve an intermediate model, wherein Megs adjacent to vascular spaces within the marrow shed large cytoplasmic fragments into the circulation, which presumably go on to form plts in the vascular space. We have now tested whether infused cultured Megs can form circulating, functional plts. Cultured Megs from the fetal livers of Day 14 wildtype (WT) C57Bl6 murine embryos grown in the presence of thrombopoietin for 10 days were separated using a bovine serum albumin gradient into two cell fractions: (1) large, mature CD41+/CD42+ Megs (average ploidy = 16–32N) and (2) an admixture of proplatelets and small CD41+/CD42+ Megs (average ploidy = 2-4N). These fractions were separately infused into hαIIb mice that expressed human, but not mouse, αIIb on their platelets. Donor-derived circulating plts were detected using species-specific antibodies to distinguish them from recipient hαIIb+ plts. Infusions of isolated WT plts as a positive control resulted in immediately detectable donor plts, and these plts lasted 24–36 hrs. Infused large Megs produced plts with delayed kinetics. Few donor plts were detectable at 5 mins, followed by a peak at 30–60 min. These plts were normal in size as determined by side-scatter and lasted for ∼24 hrs. The peak yield was ∼50-100 plts/infused Meg. In these studies, these derived plt levels reached as high as 10% of the total circulating plts in these mice who had plt counts of >8×105/μl. Maximal tolerated dose of infused large Megs was not tested. Infusion of the proplatelets/small Megs fraction generated an immediate peak of circulating plts and these lasted <24 hrs. The yield of plts was approximately equal to the number of infused proplatelets/platelets in this admixture. Half-lives of the derived plts were unaffected by the inclusion of GM6001 or TAPI-1, both of which have been reported to block metalloproteinase MMP9/ADAM17 and lengthen the half-life of culture-derived plts. Functionality of the derived plts from both cell fractions was compared to infused plts in situ using the laser-injury cremaster system. Qualitatively, derived plts were incorporated as well as infused plts into growing thrombi. Remarkably, we also detected large CD41+ cells, which circulated and occasionally became incorporated into thrombi. These cells were much more common in the proplatelet/small Meg infusions than in the large Megs infusion. Thus, our studies show that whole, mature Megs shed a significant number of plts in circulation within mice. Plts level achievable in the recipient mouse approximate a clinically relevant level. These plts are normal in size and appear to be functional. Further studies to demonstrate where plts are released from these Megs and the basis for their shortened half-life remain to be performed; however, these studies suggest an alternative source of circulating platelets and a novel strategy for generating sufficient plts from cultured Megs for clinical use. Disclosures: Poncz: Diagnostica Stago: Patents & Royalties.

Oligonucleotide probes based on 16S rRNA sequences for the identification of four Azospirillum species

1995 ◽  
Vol 41 (12) ◽  
pp. 1081-1087 ◽  
Author(s):  
Md Mahbubul Kabir ◽  
Denis Faure ◽  
Jacqueline Haurat ◽  
Philippe Normand ◽  
René Bally ◽  
...  
Keyword(s):  
16S Rrna ◽  
Oligonucleotide Probe ◽  
Oligonucleotide Probes ◽  
Probe Sequence ◽  
Bacterial Isolation ◽  
Nontarget Organisms ◽  
Isolation Techniques ◽  
Species Specific ◽  
Rrna Sequences ◽  
16S Rrna Sequences

Partial sequences of the 16S rRNA molecules of nine strains belonging to four Azospirillum species were used to design species-specific oligonucleotide probes. Azospirillum strains sequences were analyzed and three homologous fragments containing 16 nucleotides were determined. These three probes were found to be characteristic of A. lipoferum (Al), A. irakense (Ai), and A. brasilense/amazonense species (Aba) and of few nontarget organisms. The specificity of these three probes was tested both against sequences in the GenBank data base and in numerous colony hybridization experiments. As a few non-target organisms hyridized with the different Azospirillum probes, the use of these probes in bulk soil hybridization is not permitted. However, their use together with specific isolation techniques is validated.Key words: Azospirillum, bacterial isolation, hybridization, oligonucleotide probe, sequence analysis, 16S rRNA.

scholarly journals Comparison of the RpoH-Dependent Regulon and General Stress Response in Neisseria gonorrhoeae

2006 ◽  
Vol 188 (13) ◽  
pp. 4769-4776 ◽  
Author(s):  
Ishara C. Gunesekere ◽  
Charlene M. Kahler ◽  
David R. Powell ◽  
Lori A. S. Snyder ◽  
Nigel J. Saunders ◽  
...  
Keyword(s):  
Stress Response ◽  
Heat Shock ◽  
Neisseria Gonorrhoeae ◽  
Transcriptional Profiling ◽  
Transcriptional Response ◽  
Protein Homeostasis ◽  
Promoter Regions ◽  
General Stress Response ◽  
Genome Wide ◽  
Shock Proteins

ABSTRACT In the gammaproteobacteria the RpoH regulon is often equated with the stress response, as the regulon contains many of the genes that encode what have been termed heat shock proteins that deal with the presence of damaged proteins. However, the betaproteobacteria primarily utilize the HrcA repressor protein to control genes involved in the stress response. We used genome-wide transcriptional profiling to compare the RpoH regulon and stress response of Neisseria gonorrhoeae, a member of the betaproteobacteria. To identify the members of the RpoH regulon, a plasmid-borne copy of the rpoH gene was overexpressed during exponential-phase growth at 37°C. This resulted in increased expression of 12 genes, many of which encode proteins that are involved in the stress response in other species. The putative promoter regions of many of these up-regulated genes contain a consensus RpoH binding site similar to that of Escherichia coli. Thus, it appears that unlike other members of the betaproteobacteria, N. gonorrhoeae utilizes RpoH, and not an HrcA homolog, to regulate the stress response. In N. gonorrhoeae exposed to 42°C for 10 min, we observed a much broader transcriptional response involving 37 differentially expressed genes. Genes that are apparently not part of the RpoH regulon showed increased transcription during heat shock. A total of 13 genes were also down-regulated. From these results we concluded that although RpoH acts as the major regulator of protein homeostasis, N. gonorrhoeae has additional means of responding to temperature stress.

scholarly journals Re-Establishment Techniques and Transplantations of Charophytes to Support Threatened Species

Plants ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1830
Author(s):  
Irmgard Blindow ◽  
Maria Carlsson ◽  
Klaus van de Weyer
Keyword(s):  
Submerged Macrophytes ◽  
Lake Management ◽  
Life Forms ◽  
Low Fertility ◽  
Dispersal Ability ◽  
Annual Species ◽  
Temporary Habitats ◽  
Limited Dispersal ◽  
Suitable Habitats ◽  
Species Specific

Re-establishment of submerged macrophytes and especially charophyte vegetation is a common aim in lake management. If revegetation does not happen spontaneously, transplantations may be a suitable option. Only rarely have transplantations been used as a tool to support threatened submerged macrophytes and, to a much lesser extent, charophytes. Such actions have to consider species-specific life strategies. K-strategists mainly inhabit permanent habitats, are perennial, have low fertility and poor dispersal ability, but are strong competitors and often form dense vegetation. R-strategists are annual species, inhabit shallow water and/or temporary habitats, and are richly fertile. They disperse easily but are weak competitors. While K-strategists easily can be planted as green biomass taken from another site, rare R-strategists often must be reproduced in cultures before they can be planted on-site. In Sweden, several charophyte species are extremely rare and fail to (re)establish, though apparently suitable habitats are available. Limited dispersal and/or lack of diaspore reservoirs are probable explanations. Transplantations are planned to secure the occurrences of these species in the country. This contribution reviews the knowledge on life forms, dispersal, establishment, and transplantations of submerged macrophytes with focus on charophytes and gives recommendations for the Swedish project.

scholarly journals Trypanosoma brucei J-Protein 2 Functionally Co-Operates with the Cytosolic Hsp70 and Hsp70.4 Proteins

2019 ◽  
Vol 20 (23) ◽  
pp. 5843 ◽  
Author(s):  
Stephen John Bentley ◽  
Aileen Boshoff
Keyword(s):  
Heat Shock ◽  
Trypanosoma Brucei ◽  
Therapeutic Strategies ◽  
Type I ◽  
Protein Homeostasis ◽  
African Trypanosomiasis ◽  
Wide Range ◽  
Shock Proteins ◽  
Insight Into ◽  
J Protein

The etiological agent of African trypanosomiasis, Trypanosoma brucei (Tb), has been identified to possess an expanded and diverse group of heat shock proteins, which have been implicated in cytoprotection, differentiation, and subsequently progression and transmission of the disease. Heat shock protein 70 (Hsp70) is a highly conserved and ubiquitous molecular chaperone that is important in maintaining protein homeostasis in the cell. Its function is regulated by a wide range of co-chaperones, and inhibition of these functions and interactions with co-chaperones are emerging as potential therapeutic targets for numerous diseases. This study sought to biochemically characterize the cytosolic TbHsp70 and TbHsp70.4 proteins and to investigate if they functionally co-operate with the Type I J-protein, Tbj2. Expression of TbHsp70 was shown to be heat inducible, while TbHsp70.4 was constitutively expressed. The basal ATPase activities of TbHsp70.4 and TbHsp70 were stimulated by Tbj2. It was further determined that Tbj2 functionally co-operated with TbHsp70 and TbHsp70.4 as the J-protein was shown to stimulate the ability of both proteins to mediate the refolding of chemically denatured β-galactosidase. This study provides further insight into this important class of proteins, which may contribute to the development of new therapeutic strategies to combat African Trypanosomiasis.

scholarly journals Spatial and temporal plant phenological niche differentiation in the Wadi Degla desert ecosystem (Egypt)

2012 ◽  
Vol 71 (2) ◽  
pp. 261-277 ◽  
Author(s):  
Ahmad K. Hegazy ◽  
Abdelrahman A. Alatar ◽  
Jon Lovett-Doust ◽  
Hosam A. El-Adawy
Keyword(s):  
Plant Species ◽  
Niche Differentiation ◽  
Life Forms ◽  
Desert Ecosystem ◽  
Selective Pressures ◽  
Dominant Plant Species ◽  
Capparis Spinosa ◽  
Species Specific ◽  
Phenological Diversity ◽  
Study Species

AbstractTwenty dominant plant species representing different life forms were investigated phenologically over a period of 36 months (January 2004 to December 2006). Plant populations were sampled at down-, mid-, and upstream sites in a desert wadi ecosystem. The results were analyzed using TWINSPAN, DCA and CCA techniques. Five phenological niches were apparent: (1) species flowering all year round, with peaks in spring and autumn such asOchradenus baccatus; (2) species flowering during winter includingLycium shawiiandTamarix nilotica; (3) species flowering during spring, e.g.,Zillaspinosa, Zygophyllum coccineumandCapparis spinosa; (4) species flowering during summer includingIphiona mucronataandDeverra triradiata; and (5) species flowering during autumn that includeAtriplex halimusand twoAnabasisspecies. The climatic variables, including temperature, rainfall and relative humidity, affect the phenological niches and between-species differences. Within-species variations occurred between years and there were no between-site variations for most study species. The different plant species exhibited phenological diversity along the course of the wadi ecosystem. The phenological niches are species-specific and environmentally dependent rather than local selective pressures.

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