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Yong Yang, Joseph Thomas, Yunlong Li, Catherine Vilchèze, Keith M Derbyshire, William R Jacobs, Anil K Ojha
Most mycobacterial species spontaneously form biofilms, inducing unique growth physiologies and reducing drug sensitivity. Biofilm growth progresses through three genetically programmed stages: substratum attachment, intercellular aggregation and architecture maturation. Growth of Mycobacterium smegmatis biofilms requires multiple factors including a chaperonin (GroEL1) and a nucleoid-associated protein (Lsr2), although how their activities are linked remains unclear. Here we show that Lsr2 participates in intercellular aggregation, but substratum attachment of Lsr2 mutants is unaffected, thereby genetically distinguishing these developmental stages...
June 19, 2017: Molecular Microbiology
Jose H Pereira, Ryan P McAndrew, Oksana A Sergeeva, Corie Y Ralston, Jonathan A King, Paul D Adams
The human chaperonin TRiC consists of eight non-identical subunits, and its protein-folding activity is critical for cellular health. Misfolded proteins are associated with many human diseases, such as amyloid diseases, cancer, and neuropathies, making TRiC a potential therapeutic target. A detailed structural understanding of its ATP-dependent folding mechanism and substrate recognition is therefore of great importance. Of particular health-related interest is the mutation Histidine 147 to Arginine (H147R) in human TRiC subunit 5 (CCT5), which has been associated with hereditary sensory neuropathy...
June 16, 2017: Scientific Reports
Edel Pérez-López, Christine Hammond, Chrystel Olivier, Tim J Dumonceaux
The use of oligonucleotide-coupled fluorescent microspheres is a rapid, sequencing-independent, and reliable way to diagnose bacterial diseases. Previously described applications of oligonucleotide-coupled fluorescent microspheres for the detection and identification of bacteria in human clinical samples have been successfully adapted to detect and differentiate "Ca. Phytoplasma" species using as a target the chaperonin 60-encoding gene. In this chapter, we describe in detail the design and validation of oligonucleotide capture probes, and their application in the assay aiming to differentiate phytoplasma strains infecting Brassica napus and Camelina sativa plants grown in the same geographic location at the same time...
2017: Methods in Molecular Biology
Hitoshi Nakamoto, Kouji Kojima
GroELs which are prokaryotic members of the chaperonin/Hsp60 family are molecular chaperones of which Escherichia coli GroEL is a model for subsequent research. The majority of bacterial species including E. coli and Bacillus subtilis have only one essential groEL gene that forms an operon with the co-chaperone groES gene.
June 9, 2017: Physiologia Plantarum
Adrian S Enriquez, Humberto M Rojo, Jay M Bhatt, Sudheer K Molugu, Zacariah L Hildenbrand, Ricardo A Bernal
The human mitochondrial chaperonin is a macromolecular machine that catalyzes the proper folding of mitochondrial proteins and is of vital importance to all cells. This chaperonin is composed of 2 distinct proteins, Hsp60 and Hsp10, that assemble into large oligomeric complexes that mediate the folding of non-native polypeptides in an ATP dependent manner. Here, we report the bacterial expression and purification of fully assembled human Hsp60 and Hsp10 recombinant proteins and that Hsp60 forms a stable tetradecameric double-ring conformation in the absence of co-chaperonin and nucleotide...
June 8, 2017: Cell Cycle
Xiao-Min Chen, Ming-Jun Feng, Cai-Jie Shen, Bin He, Xian-Feng Du, Yi-Bo Yu, Jing Liu, Hui-Min Chu
The present study was designed to develop a novel method for identifying significant pathways associated with human hypertrophic cardiomyopathy (HCM), based on gene co‑expression analysis. The microarray dataset associated with HCM (E‑GEOD‑36961) was obtained from the European Molecular Biology Laboratory‑European Bioinformatics Institute database. Informative pathways were selected based on the Reactome pathway database and screening treatments. An empirical Bayes method was utilized to construct co‑expression networks for informative pathways, and a weight value was assigned to each pathway...
July 2017: Molecular Medicine Reports
Raza Ashraf, Majida Atta Muhammad, Naeem Rashid, Muhammad Akhtar
The chaperonin genes encoding GroELGt (ESU72018) and GroESGt (ESU72017), homologues of bacterial GroEL and GroES, from Geobacillus thermopakistaniensis were cloned and expressed in Escherichia coli. The purified gene products possessed the ATPase activity similar to other bacterial and eukaryal counterparts. Recombinant GroELGt and GroESGt were able to refold the denatured insoluble aggregates of α-amylase from Bacillus licheniformis into soluble and active form. Furthermore, GroELGt and GroESGt successfully enhanced the thermostability of porcine heart malate dehydrogenase...
June 2, 2017: Journal of Biotechnology
Timur A Mavlyutov, Huan Yang, Miles L Epstein, Arnold E Ruoho, Jay Yang, Lian-Wang Guo
The sigma-1 receptor (Sig1R) is an endoplasmic reticulum chaperonin that is attracting tremendous interest as a potential anti-neurodegenerative target. While this membrane protein is known to reside in the inner nuclear envelope (NE) and influences transcription, apparent Sig1R presence in the nucleoplasm is often observed, seemingly contradicting its NE localization. We addressed this confounding issue by applying an antibody-free approach of electron microscopy (EM) to define Sig1R nuclear localization. We expressed APEX2 peroxidase fused to Sig1R-GFP in a Sig1R-null NSC34 neuronal cell line generated with CRISPR-Cas9...
May 16, 2017: Oncotarget
Mariane Planchon, Thibaut Léger, Olivier Spalla, Gaspard Huber, Roselyne Ferrari
In a previous study, it was demonstrated that the toxic impact of titanium dioxide nanoparticles on Escherichia coli starts at 10 ppm and is closely related to the presence of little aggregates. It was also assumed that only a part of the bacterial population is able to adapt to this stress and attempts to survive. Proteomic analyses, supported by results from metabolomics, reveal that exposure of E. coli to nano-TiO2 induces two main effects on bacterial metabolism: firstly, the up-regulation of proteins and the increase of metabolites related to energy and growth metabolism; secondly, the down-regulation of other proteins resulting in an increase of metabolites, particularly amino acids...
2017: PloS One
Pavel I Semenyuk, Lidia P Kurochkina, Nikolai B Gusev, Vladimir A Izumrudov, Vladimir I Muronetz
Polyelectrolytes are a prospective tool for protection of proteins against aggregation. We compared synthetic polyanion, poly(styrene sulfonate), and natural chaperones of different types, namely, GroEL-like chaperonin from Pseudomonas aeruginosa phage EL and human small heat shock protein HspB5 (αB-crystallin), in their ability to prevent aggregation of client proteins. At 45 °C, all three agents efficiently suppressed thermal aggregation of phage endolysin. At higher temperatures, HspB5 and poly(styrene sulfonate) also inhibited endolysin aggregation, though polyanion became less efficient than HspB5 at 55 °C and 60 °C...
May 24, 2017: Biochemical and Biophysical Research Communications
Jörn-Peter Wickhorst, Abdulwahed Ahmed Hassan, Omar Hashim Sheet, Tobias Eisenberg, Osama Sammra, Mazen Alssahen, Christoph Lämmler, Ellen Prenger-Berninghoff, Michael Zschöck, Markus Timke, Amir Abdulmawjood
The present study was designed to characterize phenotypically and genotypically a Trueperella pyogenes strain isolated from a brain abscess of an adult roebuck (Capreolus capreolus). The species identity could be confirmed by phenotypical investigations, by MALDI-TOF MS analysis, and by sequencing the 16S ribosomal RNA (rRNA) gene, the 16S-23S rRNA intergenic spacer region (ISR); by sequencing the target genes rpoB, gap, and tuf; and by detection of T. pyogenes chaperonin-encoding gene cpn60 with a previously developed loop-mediated isothermal amplification (LAMP) assay...
May 23, 2017: Folia Microbiologica
Sundararajan Venkatesh, Carolyn K Suzuki
In this issue of Cell Chemical Biology,Wiechmann et al. (2017) identify mitochondrial chaperonin HSP60 as a direct target of myrtucommulone (MC), a nonprenylated acylphloroglucinol that is well known for its apoptotic activity in cancer cells. The authors propose MC as a chemical probe to study HSP60 biology and a potential chemotherapeutic agent in treating cancer and other HSP60-associated diseases.
May 18, 2017: Cell Chemical Biology
Li Zhuo, Yan Wang, Zheng Zhang, Jian Li, Xiao-Hua Zhang, Yue-Zhong Li
Chaperonin GroEL (Cpn60) requires cofactor GroES (Cpn10) for protein refolding in bacteria that possess single groEL and groES genes in a bicistronic groESL operon. Among 4,861 completely-sequenced prokaryotic genomes, 884 possess duplicate groEL genes and 770 possess groEL genes with no neighboring groES. It is unclear whether stand-alone groEL requires groES in order to function and, if required, how duplicate groEL genes and unequal groES genes balance their expressions. In Myxococcus xanthus DK1622, we determined that, while duplicate groELs were alternatively deletable, the single groES that clusters with groEL1 was essential for cell survival...
2017: Frontiers in Microbiology
Le Gao, Ryota Hidese, Shinsuke Fujiwara
Molecular chaperonin CpkB from Thermococcus kodakarensis possesses a unique negatively charged carboxy-terminal region that functions in target protein recognition. In the present study, green fluorescent protein (GFP), 4-oxalocrotonate tautomerase (4OTA) and glutamine:fructose-6-phosphate amidotransferase (GFAT) were fused with a positively charged tag, selected using docking simulation in silico, to enhance their electrostatic interactions with CpkB. Target proteins were heated at 75°C in the presence or absence of CpkB, and the remaining enzymatic activity was measured...
May 8, 2017: Journal of Bioscience and Bioengineering
Szymon Niewieczerzal, Joanna I Sulkowska
Molecular dynamics simulations are used to explore the effects of chaperonin-like cages on knotted proteins with very low sequence similarity, different depths of a knot but with a similar fold, and the same type of topology. The investigated proteins are VirC2, DndE and MJ0366 with two depths of a knot. A comprehensive picture how encapsulation influences folding rates is provided based on the analysis of different cage sizes and temperature conditions. Neither of these two effects with regard to knotted proteins has been studied by means of molecular dynamics simulations with coarse-grained structure-based models before...
2017: PloS One
Yohei Y Yamamoto, Yuko Uno, Eiryo Sha, Kentaro Ikegami, Noriyuki Ishii, Naoshi Dohmae, Hiroshi Sekiguchi, Yuji C Sasaki, Masafumi Yohda
The eukaryotic group II chaperonin, the chaperonin-containing t-complex polypeptide 1 (CCT), plays an important role in cytosolic proteostasis. It has been estimated that as much as 10% of cytosolic proteins interact with CCT during their folding process. CCT is composed of 8 different paralogous subunits. Due to its complicated structure, molecular and biochemical investigations of CCT have been difficult. In this study, we constructed an expression system for CCT from a thermophilic fungus, Chaetomium thermophilum (CtCCT), by using E...
2017: PloS One
Ranit Gruber, Michael Levitt, Amnon Horovitz
Knowing the mechanism of allosteric switching is important for understanding how molecular machines work. The CCT/TRiC chaperonin nanomachine undergoes ATP-driven conformational changes that are crucial for its folding function. Here, we demonstrate that insight into its allosteric mechanism of ATP hydrolysis can be achieved by Arrhenius analysis. Our results show that ATP hydrolysis triggers sequential ‟conformational waves." They also suggest that these waves start from subunits CCT6 and CCT8 (or CCT3 and CCT6) and proceed clockwise and counterclockwise, respectively...
May 16, 2017: Proceedings of the National Academy of Sciences of the United States of America
Katja Wiechmann, Hans Müller, Stefanie König, Natalie Wielsch, Aleš Svatoš, Johann Jauch, Oliver Werz
The acylphloroglucinol myrtucommulone A (MC) causes mitochondrial dysfunctions by direct interference leading to apoptosis in cancer cells, but the molecular targets involved are unknown. Here, we reveal the chaperonin heat-shock protein 60 (HSP60) as a molecular target of MC that seemingly modulates HSP60-mediated mitochondrial functions. Exploiting an unbiased, discriminative protein fishing approach using MC as bait and mitochondrial lysates from leukemic HL-60 cells as target source identified HSP60 as an MC-binding protein...
May 18, 2017: Cell Chemical Biology
Jie Liu, Kannan Sankar, Yuan Wang, Kejue Jia, Robert L Jernigan
Protein functional mechanisms usually require conformational changes, and often there are known structures for the different conformational states. However, usually neither the origin of the driving force nor the underlying pathways for these conformational transitions is known. Exothermic chemical reactions may be an important source of forces that drive conformational changes. Here we investigate this type of force originating from ATP hydrolysis in the chaperonin GroEL, by applying forces originating from the chemical reaction...
April 25, 2017: Biophysical Journal
Jin Chen, Qian Zhang, Weitong Ren, Wenfei Li
Despite considerable efforts, elucidating the allostery of large macromolecular assemblies at a molecular level in solution remains technically challenging due to its structural complexity. Here we have employed an approach combining amide backbone hydrogen/deuterium exchange coupled with mass spectrometry, fluorescence spectroscopy, and molecular simulations to characterize allosteric patterns of chaperonin GroEL, an ∼800 kDa tetradecamer from E. coli. Using available crystal structures of GroEL, we quantitatively map out GroEL allosteric changes in solution by resolving exchange behaviors of 133 overlapping proteolytic peptides with more than 95% sequence coverage...
May 4, 2017: Journal of Physical Chemistry. B
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