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Cryptic Shock

Jordi Pujols, Jaime Santos, Irantzu Pallarès, Salvador Ventura
Response mechanisms to external stress rely on networks of proteins able to activate specific signaling pathways to ensure the maintenance of cell proteostasis. Many of the proteins mediating this kind of response contain intrinsically disordered regions, which lack a defined structure, but still are able to interact with a wide range of clients that modulate the protein function. Some of these interactions are mediated by specific short sequences embedded in the longer disordered regions. Because the physicochemical properties that promote functional and abnormal interactions are similar, it has been shown that, in globular proteins, aggregation-prone and binding regions tend to overlap...
May 6, 2018: International Journal of Molecular Sciences
Thomas Mund, Hugh R Pelham
The Nedd4 family of HECT domain-containing E3 ligases ubiquitinate many transcription factors and signaling proteins, and their activity is tightly regulated. Normally, intramolecular interactions curb the catalytic activity of the HECT domain, but these can be broken by the binding of PY motifs, found on substrate molecules and adaptors, to the WW domains characteristic of this E3 ligase family. This raises the prospect of substrates automatically activating the ligases, frustrating the purpose of ligase regulation...
April 6, 2018: Journal of Biological Chemistry
T-M Dai, Z-C Lü, Y-S Wang, W-X Liu, X-Y Hong, F-H Wan
The Bemisia tabaci Mediterranean (MED) cryptic species is an invasive pest, distributed worldwide, with high ecological adaptability and thermotolerance. DNA methylation (a reversible chromatin modification) is one possible change that may occur within an organism subjected to environmental stress. To assess the effects of temperature stress on DNA methyltransferase 3 (Dnmt3) in MED, we cloned and sequenced BtDnmt3 and identified its functions in response to high and low temperatures. The full-length cDNA of BtDnmt3 was 3913 bp, with an open reading frame of 1962 bp, encoding a 73...
February 2018: Insect Molecular Biology
Laura Fanti, Lucia Piacentini, Ugo Cappucci, Assunta M Casale, Sergio Pimpinelli
One of the most fascinating scientific problems, and a subject of intense debate, is that of the mechanisms of biological evolution. In this context, Waddington elaborated the concepts of "canalization and assimilation" to explain how an apparently somatic variant induced by stress could become heritable through the germline in Drosophila He resolved this seemingly Lamarckian phenomenon by positing the existence of cryptic mutations that can be expressed and selected under stress. To investigate the relevance of such mechanisms, we performed experiments following the Waddington procedure, then isolated and fixed three phenotypic variants along with another induced mutation that was not preceded by any phenocopy...
August 2017: Genetics
Kai E Swenson, James D Dziura, Ani Aydin, Jesse Reynolds, Charles R Wira
Prognostication in sepsis is limited by disease heterogeneity, and measures to risk-stratify patients in the proximal phases of care lack simplicity and accuracy. Hyperlactatemia and vasopressor dependence are easily identifiable risk factors for poor outcomes. This study compares incidence and hospital outcomes in sepsis based on initial serum lactate level and vasopressor use in the emergency department (ED). In a retrospective analysis of a prospectively identified dual-center ED registry, patients with sepsis were categorized by ED vasopressor use and initial serum lactate level...
March 2018: Internal and Emergency Medicine
Etsuko Watanabe, Shoji Mano, Mika Nomoto, Yasuomi Tada, Ikuko Hara-Nishimura, Mikio Nishimura, Kenji Yamada
Heat shock protein 90 (HSP90) is a molecular chaperone that is required for the function of various substrate proteins, also known as client proteins. It is proposed that HSP90 buffers or hides phenotypic variations in animals and plants by masking mutations in some of its client proteins. However, none of the client proteins with cryptic mutations has been identified to date. Here, we identify the first client protein example by which HSP90 buffers a mutation: the auxin receptor transport inhibitor response 1 (TIR1)...
November 2016: Plant & Cell Physiology
Torsten Will, Henrike Schmidtberg, Marisa Skaljac, Andreas Vilcinskas
Heat shock protein 83 (HSP83) is homologous to the chaperone HSP90. It has pleiotropic functions in Drosophila melanogaster, including the control of longevity and fecundity, and facilitates morphological evolution by buffering cryptic deleterious mutations in wild populations. In the pea aphid Acyrthosiphon pisum, HSP83 expression is moderately induced by bacterial infection but upregulated more strongly in response to heat stress and fungal infection. Stress-inducible heat shock proteins are of considerable evolutionary and ecological importance because they are known to buffer environmental variation and to influence fitness under non-optimal conditions...
January 2017: Development Genes and Evolution
Emily L Aaronson, Michael R Filbin, David F M Brown, Kathy Tobin, Elizabeth A Mort
BACKGROUND: The release of the Center for Medicare and Medicaid Service's (CMS) latest quality measure, Severe Sepsis/Septic Shock Early Management Bundle (SEP-1), has intensified the long-standing debate over optimal care for severe sepsis and septic shock. Although the last decade of research has demonstrated the importance of comprehensive bundled care in conjunction with compliance mechanisms to reduce patient mortality, it is not clear that SEP-1 achieves this aim. The heterogeneous and often cryptic presentation of severe sepsis and septic shock, along with the multifaceted criteria for the definition of this clinical syndrome, pose a particular challenge for fitting requirements to this disease, and implementation could have unintended consequences...
January 2017: Journal of Emergency Medicine
Timothy S Travers, Lisa Harlow, Ivan O Rosas, Bernadette R Gochuico, Ted R Mikuls, Sanjoy K Bhattacharya, Carlos J Camacho, Dana P Ascherman
Post-translational protein modifications such as citrullination have been linked to the breach of immune tolerance and clinical autoimmunity. Previous studies from our laboratory support this concept, demonstrating that autoantibodies targeting citrullinated isoforms of heat shock protein 90 (HSP90) are associated with rheumatoid arthritis complicated by interstitial lung disease. To further explore the relationship between citrullination and structural determinants of HSP90 immunogenicity, we employed a combination of ELISA-based epitope profiling, computational modeling, and mass-spectrometric sequencing of peptidylarginine deiminase (PAD)-modified protein...
September 1, 2016: Journal of Immunology: Official Journal of the American Association of Immunologists
Jie-Pan Shen, Chia-Fu Chou
Morphological plasticity of bacteria is a cryptic phenomenon, by which bacteria acquire adaptive benefits for coping with changing environments. Some environmental cues were identified to induce morphological plasticity, but the underlying molecular mechanisms remain largely unknown. Physical and chemical factors causing morphological changes in bacteria have been investigated and mostly associated with potential pathways linked to the cell wall synthetic machinery. These include starvation, oxidative stresses, predation effectors, antimicrobial agents, temperature stresses, osmotic shock, and mechanical constraints...
May 2016: Biomicrofluidics
Martin Kváč, Nikola Havrdová, Lenka Hlásková, Tereza Daňková, Jiří Kanděra, Jana Ježková, Jiří Vítovec, Bohumil Sak, Ynes Ortega, Lihua Xiao, David Modrý, Jeba Rose Jennifer Jesudoss Chelladurai, Veronika Prantlová, John McEvoy
The morphological, biological, and molecular characteristics of Cryptosporidium muris strain TS03 are described, and the species name Cryptosporidium proliferans n. sp. is proposed. Cryptosporidium proliferans obtained from a naturally infected East African mole rat (Tachyoryctes splendens) in Kenya was propagated under laboratory conditions in rodents (SCID mice and southern multimammate mice, Mastomys coucha) and used in experiments to examine oocyst morphology and transmission. DNA from the propagated C...
2016: PloS One
S Saito, D Margosan, T J Michailides, C L Xiao
The Botrytis cinerea species complex comprises two cryptic species, originally referred to Group I and Group II based on Bc-hch gene RFLP haplotyping. Group I was described as a new cryptic species B. pseudocinerea During a survey of Botrytis spp. causing gray mold in blueberries and table grapes in the Central Valley of California, six isolates, three from blueberries and three from table grapes, were placed in Group I but had a distinct morphological character with conidiophores significantly longer than those of B...
March 2016: Mycologia
Robert Peuß, Hendrik Eggert, Sophie A O Armitage, Joachim Kurtz
The relationship between robustness and evolvability is a long-standing question in evolution. Heat shock protein 90 (HSP90), a molecular chaperone, has been identified as a potential capacitor for evolution, since it allows for the accumulation and release of cryptic genetic variation, and also for the regulation of novel genetic variation through transposon activity. However, to date, it is unknown whether Hsp90 expression is regulated upon demand (i.e. when the release of cryptic genetic variation is most needed)...
November 22, 2015: Proceedings. Biological Sciences
Liudmyla Kozeko, Oleksandr Talalaiev, Volodymyr Neimash, Vasyl Povarchuk
The heat shock protein 90 (HSP90) is required for the maturation and conformational regulation of many regulatory proteins affecting morphogenetic pathways and stress tolerance. The purpose of this work is to disclose a role of HSP90 in radioresistance of seeds. Arabidopsis thaliana (Ler) seeds were exposed to γ-ray irradiation with doses of 0.1-1 kGy using (60)Co source to obtain a viable but polymorphic material. A comet assay of the seeds showed a dose-dependent increase in DNA damage. Phenotypic consequences of irradiation included growth stimulation at doses of 0...
July 2015: Life Sciences in Space Research
Elisabetta Moroni, Antonella Paladino, Giorgio Colombo
Proteins are not static objects. To carry out their functions in the cells and participate in biochemical interaction networks, proteins have to explore different conformational substates, which favor the adaptation to different partners and ultimately allow them to respond to changes in the environment. In this paper we discuss the implications of including the atomistic description of protein dynamics and flexibility in the context of drug discovery and design. The underlying idea is that a better understanding of the atomistic details of molecular recognition phenomena and conformational cross-talk between a ligand and a receptor can in fact translate in unexplored opportunities for the discovery of new drug like molecules...
2015: Current Topics in Medicinal Chemistry
Jahahreeh Finley
Although the use of antiretroviral therapy (ART) has proven highly effective in controlling and suppressing HIV-1 replication, the persistence of latent but replication-competent proviruses in a small subset of CD4(+) memory T cells presents significant challenges to viral eradication from infected individuals. Attempts to eliminate latent reservoirs are epitomized by the 'shock and kill' approach, a strategy involving the combinatorial usage of compounds that influence epigenetic modulation and initiation of proviral transcription...
September 2015: Medical Hypotheses
Andrea V Gómez, Gonzalo Córdova, Roberto Munita, Guillermo E Parada, Álvaro P Barrios, Gonzalo I Cancino, Alejandra R Álvarez, María E Andrés
Causes of lower induction of Hsp70 in neurons during heat shock are still a matter of debate. To further inquire into the mechanisms regulating Hsp70 expression in neurons, we studied the activity of Heat Shock Factor 1 (HSF1) and histone posttranslational modifications (PTMs) at the hsp70 promoter in rat cortical neurons. Heat shock induced a transient and efficient translocation of HSF1 to neuronal nuclei. However, no binding of HSF1 at the hsp70 promoter was detected while it bound to the hsp25 promoter in cortical neurons during heat shock...
2015: PloS One
Ponni Rajagopal, Eric Tse, Andrew J Borst, Scott P Delbecq, Lei Shi, Daniel R Southworth, Rachel E Klevit
Small heat shock proteins (sHSPs) are essential 'holdase' chaperones that form large assemblies and respond dynamically to pH and temperature stresses to protect client proteins from aggregation. While the alpha-crystallin domain (ACD) dimer of sHSPs is the universal building block, how the ACD transmits structural changes in response to stress to promote holdase activity is unknown. We found that the dimer interface of HSPB5 is destabilized over physiological pHs and a conserved histidine (His-104) controls interface stability and oligomer structure in response to acidosis...
2015: ELife
Franziska M Schade, Lisa N S Shama, K Mathias Wegner
BACKGROUND: Pathogens are a major regulatory force for host populations, especially under stressful conditions. Elevated temperatures may enhance the development of pathogens, increase the number of transmission stages, and can negatively influence host susceptibility depending on host thermal tolerance. As a net result, this can lead to a higher prevalence of epidemics during summer months. These conditions also apply to marine ecosystems, where possible ecological impacts and the population-specific potential for evolutionary responses to changing environments and increasing disease prevalence are, however, less known...
2014: BMC Evolutionary Biology
Daniel O Thomas-Rueddel, Bernhard Poidinger, Manfred Weiss, Friedhelm Bach, Karin Dey, Helene Häberle, Udo Kaisers, Hendrik Rüddel, Dirk Schädler, Christian Scheer, Torsten Schreiber, Tobias Schürholz, Philipp Simon, Armin Sommerer, Daniel Schwarzkopf, Andreas Weyland, Gabriele Wöbker, Konrad Reinhart, Frank Bloos
PURPOSE: Current guidelines and most trials do not consider elevated lactate (Lac) serum concentrations when grading sepsis severity. We therefore assessed the association of different types of circulatory dysfunction regarding presence of hyperlactatemia and need for vasopressor support with clinical presentation and outcome of sepsis. METHODS: In a secondary analysis of a prospective observational multicenter cohort study, 988 patients with severe sepsis were investigated regarding vasopressor support, Lac levels, and outcome...
April 2015: Journal of Critical Care
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