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Eman Elagamey, Kanika Narula, Arunima Sinha, Sudip Ghosh, Magdi A E Abdellatef, Niranjan Chakraborty, Subhra Chakraborty
Extracellular matrix (ECM) is the unique organelle that perceives stress signals and reprograms molecular events of host cell during patho-stress. However, our understanding of how ECM dictates plant immunity is largely unknown. Vascular wilt caused by the soil borne filamentous fungus Fusarium oxysporum is a major impediment for global crop productivity. To elucidate the role of ECM proteins and molecular mechanism associated with cell wall mediated immunity, the temporal changes of ECM proteome was studied in vascular wilt resistant chickpea cultivar upon F...
November 16, 2017: Proteomics
Jenna T Counts, Tasha M Hester, Labib Rouhana
Chaperonin-containing Tail-less complex polypeptide 1 (CCT) is a highly conserved, hetero-oligomeric complex that ensures proper folding of actin, tubulin, and regulators of mitosis. Eight subunits (CCT1-8) make up this complex, and every subunit has a homolog expressed in the testes and somatic tissue of the planarian flatworm Schmidtea mediterranea. Gene duplications of four subunits in the genomes of S. mediterranea and other planarian flatworms created paralogs to CCT1, CCT3, CCT4, and CCT8 that are expressed exclusively in the testes...
November 2, 2017: Molecular Reproduction and Development
Keiko Kashiwagi, Yusuke Terui, Kazuei Igarashi
Polyamines exist mainly as RNA-polyamine complexes in cells. Thus, we looked for proteins whose synthesis is enhanced by polyamines at the level of translation in mammalian cells. Here, we describe how synthesis of Cct2 (T-complex protein 1, β-subunit, a chaperonin assisting in the folding actin, tubulin, and several other proteins) and eEF1A (one of the elongation factors of protein synthesis) is stimulated by polyamines at the level of translation. Polyamines stimulated Cct2 synthesis through the stimulation of ribosome shunting during 5'-processive scanning of 40S ribosomal subunits from the m(7)G-cap to the initiation codon AUG, and eEF1A synthesis through the structural change of the unusual position of a complementary sequence to 18S rRNA in eEF1A mRNA...
2018: Methods in Molecular Biology
Boudhayan Bandyopadhyay, Adi Goldenzweig, Tamar Unger, Orit Adato, Sarel J Fleishman, Ron Unger, Amnon Horovitz
The GroE chaperonin system in Escherichia coli comprises GroEL and GroES and facilitates ATP-dependent protein folding in vivo and in vitro. Proteins with very similar sequences and structures can differ in their dependence on GroEL for efficient folding. One potential but unverified source for GroEL dependence is frustration, wherein not all interactions in the native state are optimized energetically, thereby potentiating slow folding and misfolding. Here, we chose enhanced green fluorescent protein (eGFP) as a model system and subjected it to random mutagenesis, followed by screening for variants whose in vivo folding displays increased or decreased GroEL dependence...
October 24, 2017: Journal of Biological Chemistry
Toshio Takenaka, Takashi Nakamura, Saeko Yanaka, Maho Yagi-Utsumi, Mahesh S Chandak, Kazunobu Takahashi, Subhankar Paul, Koki Makabe, Munehito Arai, Koichi Kato, Kunihiro Kuwajima
We studied the interaction between GroES and a single-ring mutant (SR1) of GroEL by the NMR titration of 15N-labeled GroES with SR1 at three different temperatures (20, 25 and 30°C) in the presence of 3 mM ADP in 100 mM KCl and 10 mM MgCl2 at pH 7.5. We used SR1 instead of wild-type double-ring GroEL to precisely control the stoichiometry of the GroES binding to be 1:1 ([SR1]:[GroES]). Native heptameric GroES was very flexible, showing well resolved cross peaks of the residues in a mobile loop segment (residue 17-34) and at the top of a roof hairpin (Asn51) in the heteronuclear single quantum coherence spectra...
2017: PloS One
S Peng, Z Chu, J Lu, D Li, Y Wang, S Yang, Y Zhang
Aminoglycoside antibiotics affect protein translation fidelity and lead to protein aggregation and an increase in intracellular oxidative stress level as well. The overexpression of the chaperonin GroEL/GroES system promotes short-term tolerance to aminoglycosides in Escherichia coli. Here, we demonstrated that the coexpression of prefoldin or Hsp60 originating from the hyperthermophilic archaeon Pyrococcus furiosus in E. coli cells can rescue cell growth and inhibit protein aggregation induced by streptomycin exposure...
October 2017: Biochemistry. Biokhimii︠a︡
Young Jun An, Sara E Rowland, Jung-Hyun Na, Dario Spigolon, Seung Kon Hong, Yeo Joon Yoon, Jung-Hyun Lee, Frank T Robb, Sun-Shin Cha
The chaperonins (CPNs) are megadalton sized hollow complexes with two cavities that open and close to encapsulate non-native proteins. CPNs are assigned to two sequence-related groups that have distinct allosteric mechanisms. In Group I CPNs a detachable co-chaperone, GroES, closes the chambers whereas in Group II a built-in lid closes the chambers. Group I CPNs have a bacterial ancestry, whereas Group II CPNs are archaeal in origin. Here we describe open and closed crystal structures representing a new phylogenetic branch of CPNs...
October 10, 2017: Nature Communications
Claudia Sangiorgi, Davide Vallese, Isabella Gnemmi, Fabio Bucchieri, Bruno Balbi, Paola Brun, Angelo Leone, Andrea Giordano, Everly Conway de Macario, Alberto Jl Macario, Francesco Cappello, Antonino Di Stefano
HSP60 has been implicated in chronic inflammatory disease pathogenesis, including chronic obstructive pulmonary disease (COPD), but the mechanisms by which this chaperonin would act are poorly understood. A number of studies suggest a role for extracellular HSP60, since it can be secreted from cells and bind Toll-like receptors; however, the effects of this stimulation have never been extensively studied. We investigated the effects (pro- or anti-inflammatory) of HSP60 in human bronchial epithelial cells (16-HBE) alone and in comparison with oxidative, inflammatory, or bacterial challenges...
October 1, 2017: International Journal of Immunopathology and Pharmacology
Xuejun Zhao, Jiangfan Xiu, Yan Li, Huiling Ma, Jianwei Wu, Bo Wang, Guo Guo
Chaperonins, belonging to the T-complex protein-1 (TCP-1) family, assist in the correct folding of nascent and misfolded proteins. It is well-known that in mammals, the zeta subunit of the TCP-1 complex (TCP-1ζ) plays a vital role in the folding and assembly of cytoskeleta proteins. This study reported for the first time the cloning, characterization and expression pattern analysis of the TCP-1ζ from Musca domestica, which was named as MdTCP-1ζ. The MdTCP-1ζ cDNA is 1,803 bp long with a 1,596 bp open reading frame that encodes a protein with 531 bp amino acids...
July 1, 2017: Journal of Insect Science
Hongjun Gao, Min Zheng, Sijin Sun, Hongwu Wang, Zhigang Yue, Yun Zhu, Xiaochen Han, Junquan Yang, Yanqiu Zhou, Yiran Cai, Wanning Hu
Novel tumor antigens and their related autoantibodies have tremendous potential for early diagnosis of non-small cell lung cancer (NSCLC). In this study, we identify antigens from NSCLC tissue and autoantibodies in sera of patients with NSCLC using a modified proteomics-based approach. We seperated and identified four NSCLC-associated proteins extracted from the cytosol in tumor tissues by mini-two-dimensional gel electrophoresis, followed by Western blot and hybridization with individual sera for confirmation of antibody binding...
September 8, 2017: Oncotarget
Fei-He Ma, Yingli An, Jianzu Wang, Yiqing Song, Yang Liu, Linqi Shi
The folding process of a protein is inherently error-prone, owing to the large number of possible conformations that a protein chain can adopt. Partially folded or misfolded proteins typically expose hydrophobic surfaces and tend to form dysfunctional protein aggregates. Therefore, materials that can stabilize unfolded proteins and then efficiently assist them refolding to its bioactive form are of significant interest. Inspired by natural chaperonins, we have synthesized a series of polymeric nanochaperones that can facilitate the refolding of denatured proteins with a high recovery efficiency (up to 97%)...
October 24, 2017: ACS Nano
Xiaolong Ke, Wenxuan Zou, Yafang Ren, Zhiqin Wang, Jin Li, Xuan Wu, Jie Zhao
Chaperonins are a class of molecular chaperones that assist in the folding and assembly of a wide range of substrates. In plants, chloroplast chaperonins are composed of two different types of subunits, Cpn60α and Cpn60β, and duplication of Cpn60α and Cpn60β genes occurs in a high proportion of plants. However, the importance of multiple Cpn60α and Cpn60β genes in plants is poorly understood. In this study, we found that loss-of-function of CPNA2 (AtCpn60α2), a gene encoding the minor Cpn60α subunit in Arabidopsis thaliana, resulted in arrested embryo development at the globular stage, whereas the other AtCpn60α gene encoding the dominant Cpn60α subunit, CPNA1 (AtCpn60α1), mainly affected embryonic cotyledon development at the torpedo stage and thereafter...
September 2017: PLoS Genetics
Manajit Hayer-Hartl
Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) mediates the fixation of atmospheric CO2 in photosynthesis by catalyzing the carboxylation of the 5-carbon sugar ribulose-1,5-bisphosphate (RuBP). Despite its pivotal role, Rubisco is an inefficient enzyme and thus has been a key target for bioengineering. However, efforts to increase crop yields by Rubisco engineering remain unsuccessful, due in part to the complex machinery of molecular chaperones required for Rubisco biogenesis and metabolic repair...
September 27, 2017: Protein Science: a Publication of the Protein Society
Marielle A Wälti, G Marius Clore
GroEL, a prototypical member of the chaperonin class of chaperones, is a large supramocular machine that assists protein folding and plays an important role in proteostasis. GroEL comprises two heptameric rings, each of which encloses a large cavity that provides a folding chamber for protein substrates. Many questions remain regarding the mechanistic details of GroEL facilitated protein folding. Thus, data at atomic resolution of the type provided by NMR and EPR are invaluable. Such studies often require complete deuteration of GroEL, uniform or residue specific (13)C and (15)N isotope labeling, and the introduction of selective cysteine mutations for site-specific spin labeling...
February 2018: Protein Expression and Purification
Seunghyun Sim, Takuzo Aida
In this Account, "a step toward clinical nanorobots" is proposed as one of the Holy Grails in chemistry, which could lead to a great leap in the field of biomedicines when accomplished. We review our preliminary contributions to this challenge by engineering chaperonin protein GroEL to generate de novo structures and functions.
March 21, 2017: Accounts of Chemical Research
Yan-Jin Liu, Vathan Kumar, Yuan-Feng Lin, Po-Huang Liang
We have previously demonstrated the ability of I-Trp to disrupt the protein-protein interaction of β-tubulin with chaperonin-containing TCP-1β (CCT-β). This caused more severe apoptosis in multidrug-resistant MES-SA/Dx5, compared to MES-SA, due to its higher CCT-β overexpression. In this study, we screened a panel of cancer cell lines, finding CCT-β overexpression in the triple-negative breast cancer cell line MDA-MB-231, colorectal cancer cell lines Colo205 and HCT116, and a gastric cancer cell line MKN-45...
September 14, 2017: Cell Death & Disease
Beatriz Temer, Leandro Vieira Dos Santos, Victor Augusti Negri, Juliana Pimentel Galhardo, Pedro Henrique Mello Magalhães, Juliana José, Cidnei Marschalk, Thamy Lívia Ribeiro Corrêa, Marcelo Falsarella Carazzolle, Gonçalo Amarante Guimarães Pereira
BACKGROUND: Second-generation ethanol production is a clean bioenergy source with potential to mitigate fossil fuel emissions. The engineering of Saccharomyces cerevisiae for xylose utilization is an essential step towards the production of this biofuel. Though xylose isomerase (XI) is the key enzyme for xylose conversion, almost half of the XI genes are not functional when expressed in S. cerevisiae. To date, protein misfolding is the most plausible hypothesis to explain this phenomenon...
September 9, 2017: BMC Biotechnology
Vittorio Fineschi, Rocco Valerio Viola, Raffaele La Russa, Alessandro Santurro, Paola Frati
Perinatal hypoxic-ischemic brain injury, as a result of chronic, subacute, and acute insults, represents the pathological consequence of fetal distress and birth or perinatal asphyxia, that is, "nonreassuring fetal status." Hypoxic-ischemic injury (HII) is typically characterized by an early phase of damage, followed by a delayed inflammatory local response, in an apoptosis-necrosis continuum. In the early phase, the cytotoxic edema and eventual acute lysis take place; with reperfusion, additional damage should be assigned to excitotoxicity and oxidative stress...
2017: Mediators of Inflammation
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...
August 1, 2017: Oncotarget
Mingliang Jin, Yao Cong
No abstract text is available yet for this article.
September 7, 2017: Nature Structural & Molecular Biology
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