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Lior Doron, Pierre Goloubinoff, Michal Shapira
Photosynthesis is performed by large complexes, composed of subunits encoded by the nuclear and chloroplast genomes. Assembly is assisted by general and target-specific chaperones, but their mode of action is yet unclear. We formerly showed that ZnJ2 is an algal chaperone resembling BSD2 from land plants. In algae, it co-migrates with the rbcL transcript on chloroplast polysomes, suggesting it contributes to the de-novo synthesis of RbcL (Doron et al., 2014). ZnJ2 contains four CXXCXGXG motifs, comprising a canonical domain typical also of DnaJ-type I (DNAJA)...
2018: Frontiers in Molecular Biosciences
Judit Perales-Calvo, David Giganti, Guillaume Stirnemann, Sergi Garcia-Manyes
It is well established that chaperones modulate the protein folding free-energy landscape. However, the molecular determinants underlying chaperone-mediated mechanical folding remain largely elusive, primarily because the force-extended unfolded conformation fundamentally differs from that characterized in biochemistry experiments. We use single-molecule force-clamp spectroscopy, combined with molecular dynamics simulations, to study the effect that the Hsp70 system has on the mechanical folding of three mechanically stiff model proteins...
February 2018: Science Advances
Elena R Toenshoff, Peter D Fields, Yann X Bourgeois, Dieter Ebert
The planktonic freshwater crustacean of the genus Daphnia are a model system for biomedical research and, in particular, invertebrate-parasite interactions. Up until now, no virus has been characterized for this system. Here we report the discovery of an iridovirus as the causative agent of White Fat Cell Disease (WFCD) in Daphnia WFCD is a highly virulent disease of Daphnia that can easily be cultured under laboratory conditions. Although it has been studied from sites across Eurasia for more than 60 years, its causative agent had not been described, nor had an iridovirus been connected to WFCD before now...
February 27, 2018: G3: Genes—Genomes—Genetics
Duncan C Krause, Songye Chen, Jian Shi, Ashley Jensen, Edward S Sheppard, Grant J Jensen
The Mycoplasma pneumoniae terminal organelle functions in adherence and gliding motility and is comprised of at least eleven substructures. We used electron cryotomography to correlate impaired gliding and adherence function with changes in architecture in diverse terminal organelle mutants. All eleven substructures were accounted for in the prkC, prpC, and P200 mutants, and variably so for the HMW3 mutant. Conversely, no terminal organelle substructures were evident in HMW1 and HMW2 mutants. The P41 mutant exhibits a terminal organelle detachment phenotype and lacked the bowl element normally present at the terminal organelle base...
February 22, 2018: Molecular Microbiology
Minchul Seo, S K M Azizul Islam, Seong-Su Moon
Hypothalamus is the regulatory center of both appetite and energy balance, and endoplasmic reticulum (ER) stress in the hypothalamus is involved in the pathogenesis of obesity. Recently, inhibition of 11 β hydroxysteroid dehydrogenase type1 (11β-HSD1) was reported to have an anti-obesity effect by reducing fat mass. However, link between the role of 11β-HSD1 in hypothalamus and obesity has yet to be elucidated. In this study, embryonal primary hypothalamic neurons and high fat diet (HFD) fed mice were used to investigate the anorexigenic effects of 11β-HSD1 inhibitors in in vitro and in vivo...
February 8, 2018: Journal of Neuroendocrinology
Anna Wanecka, Jarosław Król, Jan Twardoń, Jacek Mrowiec, Jacek Bania, Agnieszka Korzeniowska-Kowal, Anna Tobiasz
The aim of this paper is to describe a novel subpopulation of Staphylococcus haemolyticus isolated from intramammary gland infections (IMI) in cattle. In total, eight isolates originating from milk samples from two unrelated dairy farms were examined phenotypically (using the ID 32 STAPH system) and genotypically. These isolates had almost identical sequences of each of the housekeeping genes examined (dnaJ, rpoB and sodA) but these sequences displayed similarity of only ∼92.5%, 95.0% and 96.8%, respectively, with known S...
February 2018: Veterinary Microbiology
Katharina B Beer, Jennifer Rivas-Castillo, Kenneth Kuhn, Gholamreza Fazeli, Birgit Karmann, Jeremy F Nance, Christian Stigloher, Ann M Wehman
Cells release extracellular vesicles (EVs) that mediate intercellular communication and repair damaged membranes. Despite the pleiotropic functions of EVs in vitro, their in vivo function is debated, largely because it is unclear how to induce or inhibit their formation. In particular, the mechanisms of EV release by plasma membrane budding or ectocytosis are poorly understood. We previously showed that TAT-5 phospholipid flippase activity maintains the asymmetric localization of the lipid phosphatidylethanolamine (PE) in the plasma membrane and inhibits EV budding by ectocytosis in Caenorhabditis elegans However, no proteins that inhibit ectocytosis upstream of TAT-5 were known...
January 24, 2018: Proceedings of the National Academy of Sciences of the United States of America
Monica Modesto, Samanta Michelini, Kaihei Oki, Bruno Biavati, Koichi Watanabe, Paola Mattarelli
In our previous study based on hsp60 PCR-restriction fragment length polymorphism and 16S rRNA gene sequencing, we stated that the bifidobacterial strains isolated from the individual faecal samples of five baby common marmosets constituted different phylogenetically isolated groups of the genus Bifidobacterium. In that study, we also proposed that these isolated groups potentially represented novel species of the genus Bifidobacterium. Out of them, Bifidobacterium aesculapii, Bifidobacterium myosotis, Bifidobacterium tissieri and Bifidobacterium hapali, have been described recently...
January 4, 2018: International Journal of Systematic and Evolutionary Microbiology
Yongliang Shang, Jie Yan, Wenhao Tang, Chao Liu, Sai Xiao, Yueshuai Guo, Li Yuan, Liang Chen, Hui Jiang, Xuejiang Guo, Jie Qiao, Wei Li
Acephalic spermatozoa syndrome has been reported for many decades; it is characterized by very few intact spermatozoa and tailless sperm heads in the semen and causes severe male infertility. The only gene whose mutations have been found to be associated with this syndrome encodes Sad1 and UNC84 domain-containing 5 (SUN5), a testis-specific nuclear envelope protein. The functional role of SUN5 has been well studied in mouse models, but the molecular basis for the pathogenic effects of mutations in the human SUN5 gene remain elusive...
January 3, 2018: Journal of Biological Chemistry
Roman Kityk, Jürgen Kopp, Matthias P Mayer
Efficient targeting of Hsp70 chaperones to substrate proteins depends on J-domain cochaperones, which in synergism with substrates trigger ATP hydrolysis in Hsp70s and concomitant substrate trapping. We present the crystal structure of the J-domain of Escherichia coli DnaJ in complex with the E. coli Hsp70 DnaK. The J-domain interacts not only with DnaK's nucleotide-binding domain (NBD) but also with its substrate-binding domain (SBD) and packs against the highly conserved interdomain linker. Mutational replacement of contacts between J-domain and SBD strongly reduces the ability of substrates to stimulate ATP hydrolysis in the presence of DnaJ and compromises viability at heat shock temperatures...
January 18, 2018: Molecular Cell
Marcia Y Maier, Lisanne Luks, Oliver Baudendistel, Valentin Wittmann, Daniel R Dietrich
Propiverine, a frequently-prescribed pharmaceutical for the treatment of symptoms associated with overactive bladder syndrome, provoked massive intranuclear and cytosolic protein inclusions in rat proximal tubule epithelium, primarily consisting of the peroxisomal targeting signal 1 (PTS1) containing protein d-amino acid oxidase (DAAO). As this type of nephropathy was also observed for other drugs, the aim was to determine whether propiverine interferes with trafficking and/or import of peroxisomal proteins...
December 19, 2017: Chemico-biological Interactions
Xibing Xu, Ke Liang, Yulong Niu, Yan Shen, Xuedong Wan, Haiyan Li, Yi Yang
In Escherichia coli, the DnaK/DnaJ chaperone can control the stability and activity of σ32, which is the key factor in heat shock response. Heterologous expression of eukaryotic molecular chaperones protects E. coli from heat stress. Here, we show that BAH1, an E3 ligase from plant that has a similar zinc finger domain to DnaJ, can perform block the effect of DnaK on σ32 in Escherichia coli. By constructing a chimeric DnaJ protein, with the J-domain of DnaJ fused to BAH1, we found BAH1 could partially compensate for the DnaJ' zinc finger domain in vivo, and that it was dependent on the zinc finger domain of BAH1...
December 20, 2017: Current Microbiology
Xiaofang Wang, Taixian Yuan, Jun Yuan, Yufeng Su, Xiaoyu Sun, Jingwen Wu, Hong Zhang, Xun Min, Xuemei Zhang, Yibing Yin
The fusion protein DnaJ-ΔA146Ply could induce cross-protective immunity against pneumococcal infection via mucosal and subcutaneous immunization in mice in the absence of additional adjuvants. DnaJ and Ply are both Toll-like receptor 4 (TLR4) but not TLR2 ligands. However, we found that TLR2-/- mice immunized subcutaneously with DnaJ-ΔA146Ply showed significantly lower survival rates and higher bacterial loads in nasal washes than did wild-type (WT) mice after being challenged with pneumococcal strain D39 or 19F...
March 2018: Infection and Immunity
Christina Zarouchlioti, David A Parfitt, Wenwen Li, Lauren M Gittings, Michael E Cheetham
Maintenance of protein homeostasis is vitally important in post-mitotic cells, particularly neurons. Neurodegenerative diseases such as polyglutamine expansion disorders-like Huntington's disease or spinocerebellar ataxia (SCA), Alzheimer's disease, fronto-temporal dementia (FTD), amyotrophic lateral sclerosis (ALS) and Parkinson's disease-are often characterized by the presence of inclusions of aggregated protein. Neurons contain complex protein networks dedicated to protein quality control and maintaining protein homeostasis, or proteostasis...
January 19, 2018: Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
Noemí Buján, Haitham Mohammed, Sabela Balboa, Jesús L Romalde, Alicia E Toranzo, Cova R Arias, Beatriz Magariños
Until 2012, the genus Edwardsiella was composed by three species Edwardsiella tarda, Edwardsiella hoshinae and Edwardsiella ictaluri. In 2013, Edwardsiella piscicida, compiling fish pathogenic strains previously identified as E. tarda was described, and more recently a new species isolated from diseased eel was reported, namely Edwardsiella anguillarum. The incorporation of these species into the genus makes necessary a revision of the taxonomic position of the isolates previously identified as E. tarda. Using AFLP technique, MLSA studies and in silico DNA-DNA hybridization, 46 of 49 E...
November 3, 2017: Systematic and Applied Microbiology
V Vishnu Prasanth, M Suchandranath Babu, Ramana K Basava, V G N Tripura Venkata, Satendra K Mangrauthia, S R Voleti, Sarla Neelamraju
Wild species and derived introgression lines (ILs) are a good source of genes for improving complex traits such as heat tolerance. The effect of heat stress on 18 yield traits was studied in four treatments in two seasons, under field conditions by subjecting 37 ILs and recurrent parents Swarna and KMR3, N22 mutants, and wild type and 2 improved rice cultivars to heat stress using polycover house method in wet season and late sowing method in dry season. Normal grown unstressed plants were controls. Both correlation and path coefficient analysis showed that the major contributing traits for high yield per plant (YPP) under heat stress conditions were tiller number, secondary branches in panicle, filled grain number, and percent spikelet fertility...
2017: Frontiers in Plant Science
Monica Modesto, Samanta Michelini, Maria Cristina Sansosti, Carlotta De Filippo, Duccio Cavalieri, Linnea Qvirist, Thomas Andlid, Caterina Spiezio, Camillo Sandri, Stefano Pascarelli, Barbara Sgorbati, Paola Mattarelli
Three Gram-stain-positive, non-spore-forming, microaerophilic and fructose-6-phosphate phosphoketolase positive strains were isolated from a faecal sample of an adult subject of the emperor tamarin (Saguinus imperator). Given that the isolates revealed identical BOX PCR profiles, strain TRI 5(T) was selected as a representative and characterized further. Comparative analysis of 16S rRNA gene sequence similarity revealed that strain TRI 5(T) was closely related to Bifidobacterium saguini DSM 23967(T) (96.4 %) and to Bifidobacterium longum subsp...
November 8, 2017: International Journal of Systematic and Evolutionary Microbiology
Andrea Lampis, Pietro Carotenuto, Georgios Vlachogiannis, Luciano Cascione, Somaieh Hedayat, Rosemary Burke, Paul Clarke, Else Bosma, Michele Simbolo, Aldo Scarpa, Sijia Yu, Rebecca Cole, Elizabeth Smyth, Javier Fernández Mateos, Ruwaida Begum, Blanka Hezelova, Zakaria Eltahir, Andrew Wotherspoon, Nicos Fotiadis, Maria Antonietta Bali, Chirag Nepal, Khurum Khan, Mark Stubbs, Jens C Hahne, Pierluigi Gasparini, Vincenza Guzzardo, Carlo M Croce, Suzanne Eccles, Matteo Fassan, David Cunningham, Jesper B Andersen, Paul Workman, Nicola Valeri, Chiara Braconi
BACKGROUND & AIMS: Cholangiocarcinomas (CCA) are resistant to chemotherapy, so new therapeutic agents are needed. We performed a screen to identify small molecule compounds that are active against CCAs. Levels of microRNA 21 (MIR21 or miRNA21) are increased in CCAs. We investigated whether miRNA21 mediates resistance of CCA cells and organoids to HSP90 inhibitors. METHODS: We performed a high-throughput screen of 484 small molecule compounds to identify those that reduced viability of 6 human CCA cell lines...
November 4, 2017: Gastroenterology
Zohreh Jahangirizadeh, Hossein Ghafouri, Reza H Sajedi, Sajjad Sarikhan, Majid Taghdir, Reyhaneh Sariri
A novel Hsp70 chaperone from Rutilus frisii kutum was identified, cloned, expressed, purified and its functional characteristics revealed. The 3D structure of Hsp70 from Rutilus kutum was constructed using the crystal structure of E. coli Hsp70 as the template, with 47% sequence identity. The in vitro ATPase activity assay after 60minutes, ATP hydrolysis of purified recombinant Hsp70 (8μM) was improved by binding to denatured thermally luciferase (3μM) about 2.5-fold compared with that of Hsp70 alone. Based on the results, it was found that the purified Hsp70 chaperone was able to considerably suppress heat-induced aggregation of luciferase by binding to DnaJ co-chaperone (5μM) more than 70% after 10min at 42°C...
October 28, 2017: International Journal of Biological Macromolecules
Nicole K Andeen, Han-Yin Yang, Dao-Fu Dai, Michael J MacCoss, Kelly D Smith
Fibrillary GN is a rare form of GN of uncertain pathogenesis that is characterized by the glomerular accumulation of randomly arranged, nonbranching fibrils (12-24 nm) composed of Ig and complement proteins. In this study, we used mass spectrometry to comprehensively define the glomerular proteome in fibrillary GN compared with that in controls and nonfibrillary GN renal diseases. We isolated glomeruli from formalin-fixed and paraffin-embedded biopsy specimens using laser capture microdissection and analyzed them with liquid chromatography and data-dependent tandem mass spectrometry...
November 2, 2017: Journal of the American Society of Nephrology: JASN
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