A critical role for highly conserved Glu610 residue of oligopeptidase B from Trypanosoma brucei in thermal stability

2009 ◽  
Vol 147 (2) ◽  
pp. 201-211 ◽  
Author(s):  
N. I. Mohd Ismail ◽  
T. Yuasa ◽  
K. Yuasa ◽  
Y. Nambu ◽  
M. Nisimoto ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Trypanosoma Brucei ◽  
Critical Role ◽  
Oligopeptidase B

scholarly journals The Nuclear Export Receptors TbMex67 and TbMtr2 Are Required for Ribosome Biogenesis in Trypanosoma brucei

mSphere ◽  
2019 ◽  
Vol 4 (4) ◽  
Author(s):  
Constance Rink ◽  
Martin Ciganda ◽  
Noreen Williams
Keyword(s):  
Trypanosoma Brucei ◽  
Nuclear Export ◽  
Ribosome Biogenesis ◽  
Biological Process ◽  
Large Subunit ◽  
Critical Role ◽  
Ribosomal Subunits ◽  
Content Type ◽  
Protein Components ◽  
Export Receptors

ABSTRACT Ribosomal maturation is a complex and highly conserved biological process involving migration of a continuously changing RNP across multiple cellular compartments. A critical point in this process is the translocation of individual ribosomal subunits (60S and 40S) from the nucleus to the cytoplasm, and a number of export factors participate in this process. In this study, we characterize the functional role of the auxiliary export receptors TbMex67 and TbMtr2 in ribosome biogenesis in the parasite Trypanosoma brucei. We demonstrate that depletion of each of these proteins dramatically impacts the steady-state levels of other proteins involved in ribosome biogenesis, including the trypanosome-specific factors P34 and P37. In addition, we observe that the loss of TbMex67 or TbMtr2 leads to aberrant ribosome formation, rRNA processing, and polysome formation. Although the TbMex67-TbMtr2 heterodimer is structurally distinct from Mex67-Mtr2 complexes previously studied, our data show that they retain a conserved function in ribosome biogenesis. IMPORTANCE The nuclear export of ribosomal subunits (60S and 40S) depends in part on the activity of the essential auxiliary export receptors TbMtr2 and TbMex67. When these proteins are individually depleted from the medically and agriculturally significant parasite Trypanosoma brucei, distinct alterations in the processing of the rRNAs of the large subunit (60S) are observed as well as aberrations in the assembly of functional ribosomes (polysomes). We also established that TbMex67 and TbMtr2 interact directly or indirectly with the protein components of the 5S RNP, including the trypanosome-specific P34/P37. The critical role that TbMex67 and TbMtr2 play in this essential biological process together with their parasite-specific interactions may provide new therapeutic targets against this important parasite.

scholarly journals POSS Nanofiller-Induced Enhancement of the Thermomechanical Properties in a Fluoroelastomer Terpolymer

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1358 ◽  
Author(s):  
Daphné Berthier ◽  
Marie-Pierre Deffarges ◽  
Nicolas Berton ◽  
Mathieu Venin ◽  
Florian Lacroix ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Thermal Stability ◽  
Critical Role ◽  
Thermomechanical Properties ◽  
Polyhedral Oligomeric Silsesquioxanes ◽  
Microscopy Imaging ◽  
Composite Thin Films ◽  
Covalent Grafting ◽  
Dispersion State

The present study reports on the use of three types of polyhedral oligomeric silsesquioxanes (POSS) nanoparticles with various organic substituents as fillers in a fluoroelastomer (FKM). A series of/POSS elastomer composite thin films is prepared. Microstructural SEM/TEM (scanning electron microscopy/transmission electron microscopy) imaging reveals a dispersion state allowing the presence of micron-sized domains. The influence of POSS content is studied in order to optimize thermal stability and mechanical properties of the composite thin films. Both POSS-A (with an acryloyl functional group and seven isobutyl substituents) and POSS-P (with eight phenyl substituents) lead to higher thermal stability and modulus of the composites, with respect to the unfilled FKM terpolymer matrix. covalent grafting of POSS-A onto the FKM network is found to play a critical role. Enhanced storage modulus in the rubbery plateau region (+210% at 200 °C for 20 phr) suggests that POSS-A is particularly suitable for high temperature applications.

scholarly journals A potential role for a novel ZC3H5 complex in regulating mRNA translation in Trypanosoma brucei

2020 ◽  
Vol 295 (42) ◽  
pp. 14291-14304
Author(s):  
Kathrin Bajak ◽  
Kevin Leiss ◽  
Christine Clayton ◽  
Esteban Erben
Keyword(s):  
Gene Expression ◽  
Trypanosoma Brucei ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Binding Protein ◽  
Affinity Purification ◽  
Critical Role ◽  
Rna Binding Protein ◽  
Mrna Translation

In Trypanosoma brucei and related kinetoplastids, gene expression regulation occurs mostly posttranscriptionally. Consequently, RNA-binding proteins play a critical role in the regulation of mRNA and protein abundance. Yet, the roles of many RNA-binding proteins are not understood. Our previous research identified the RNA-binding protein ZC3H5 as possibly involved in gene repression, but its role in controlling gene expression was unknown. We here show that ZC3H5 is an essential cytoplasmic RNA-binding protein. RNAi targeting ZC3H5 causes accumulation of precytokinetic cells followed by rapid cell death. Affinity purification and pairwise yeast two-hybrid analysis suggest that ZC3H5 forms a complex with three other proteins, encoded by genes Tb927.11.4900, Tb927.8.1500, and Tb927.7.3040. RNA immunoprecipitation revealed that ZC3H5 is preferentially associated with poorly translated, low-stability mRNAs, the 5′-untranslated regions and coding regions of which are enriched in the motif (U/A)UAG(U/A). As previously found in high-throughput analyses, artificial tethering of ZC3H5 to a reporter mRNA or other complex components repressed reporter expression. However, depletion of ZC3H5 in vivo caused only very minor decreases in a few targets, marked increases in the abundances of very stable mRNAs, an increase in monosomes at the expense of large polysomes, and appearance of “halfmer” disomes containing two 80S subunits and one 40S subunit. We speculate that the ZC3H5 complex might be implicated in quality control during the translation of suboptimal open reading frames.

Critical role of atomic-scale defect disorders for high-performance nanostructured half-Heusler thermoelectric alloys and their thermal stability

2019 ◽  
Vol 180 ◽  
pp. 97-104 ◽  
Author(s):  
Ho Jae Lee ◽  
Kyu Hyoung Lee ◽  
Liangwei Fu ◽  
GyeongTak Han ◽  
Hyun-Sik Kim ◽  
...  
Keyword(s):  
Thermal Stability ◽  
High Performance ◽  
Critical Role ◽  
Atomic Scale

Trypanosoma brucei brucei oligopeptidase B null mutants display increased prolyl oligopeptidase-like activity

2012 ◽  
Vol 182 (1-2) ◽  
pp. 7-16 ◽  
Author(s):  
Richard T. Kangethe ◽  
Alain F.V. Boulangé ◽  
Virginie Coustou ◽  
Théo Baltz ◽  
Theresa H.T. Coetzer
Keyword(s):  
Trypanosoma Brucei ◽  
Prolyl Oligopeptidase ◽  
Trypanosoma Brucei Brucei ◽  
Oligopeptidase B ◽  
Null Mutants

Thermal Stability of NiAl-Base Coatings for High Temperature Application

2005 ◽  
Vol 237-240 ◽  
pp. 709-714
Author(s):  
Robert Filipek ◽  
Marek Danielewski ◽  
E. Tyliszczak ◽  
M. Pawełkiewicz ◽  
S. Datta
Keyword(s):  
Thermal Stability ◽  
Gas Turbines ◽  
Inverse Method ◽  
Critical Role ◽  
Diffusion Coatings ◽  
Aluminide Coatings ◽  
Wide Range ◽  
Industrial Energy ◽  
Temperature Application ◽  
Thermal Stability Of

Aluminide diffusion coatings act as a remedy against the aggressive environments in which modern aero-gas turbines operate. Platinum addition to basic aluminide coatings significantly improves the oxidation resistance of these coatings. The increase in operating temperatures of industrial energy systems and gas turbines, has led to the extensive use of coatings capable of providing improved service life. Interdiffusion plays a critical role in understanding the integrity of such coatings. The Danielewski-Holly model of interdiffusion which allows for the description of a wide range of processes (including processes stimulated by reactions at interfaces) is employed for studying of interdiffusion in the Pt-modified β-NiAl coatings. Using the inverse method the intrinsic diffusivities of Ni, Al and Pt were calculated. Such obtained diffusivities were subsequently used for modelling of thermal stability of Pt-modified aluminide coatings in air and in argon atmosphere.

Diverse Structures and Physicochemical Properties of Four Zinc–Tripyridyltriazole Coordination Polymers Regulated by Counter-Ions

2016 ◽  
Vol 69 (1) ◽  
pp. 33 ◽  
Author(s):  
Xi Wang ◽  
Ya-Mei Guo
Keyword(s):  
Thermal Stability ◽  
Coordination Polymers ◽  
Critical Role ◽  
Structural Diversity ◽  
Counter Ions ◽  
1D Chain ◽  
Synergistic Modulation ◽  
Multiple Conformations ◽  
Coordination Patterns ◽  
Organic Linker

Four distinct ZnII coordination polymers [Zn(L5)Cl2]n (1), [Zn(L5)I2]n (2), {[Zn(L5)(N3)2](H2O)2}n (3), and {[Zn(L5)2(H2O)](ClO4)2(CH3OH)}n (4) were prepared by assembling a multidentate tripyridyltriazole building block 3-(2-pyridyl)-4-(4-pyridyl)-5-(3-pyridyl)-1,2,4-triazole (L5) with different ZnII salts. Compounds 1, 2 and 4 display distinguishing 1D chain-like coordination patterns whereas 3 reveals a 2D uninodal four-connected network, which can be well regulated by different counter-ions. Further, the building tecton L5 exhibits multiple conformations in these structures. The structural diversity reveals that the synergistic modulation of counter-ions and the adaptable conformations of the organic linker play a critical role in the structural construction. Solid-state properties including thermal stability and fluorescence were investigated as well.

scholarly journals An Evolutionarily Conserved Coiled-Coil Protein Implicated in Polycystic Kidney Disease Is Involved in Basal Body Duplication and Flagellar Biogenesis in Trypanosoma brucei

2005 ◽  
Vol 25 (9) ◽  
pp. 3774-3783 ◽  
Author(s):  
Gareth W. Morgan ◽  
Paul W. Denny ◽  
Sue Vaughan ◽  
David Goulding ◽  
Tim R. Jeffries ◽  
...  
Keyword(s):  
Kidney Disease ◽  
Polycystic Kidney Disease ◽  
Trypanosoma Brucei ◽  
Basal Body ◽  
Critical Role ◽  
Coiled Coil ◽  
Specific Protein ◽  
Polycystic Kidney ◽  
Wide Range ◽  
Flagellar Biogenesis

ABSTRACT Trypanosoma brucei is a flagellated protozoan with a highly polarized cellular structure. TbLRTP is a trypanosomal protein containing multiple SDS22-class leucine-rich repeats and a coiled-coil domain with high similarity to a mammalian testis-specific protein of unknown function. Homologues are present in a wide range of higher eukaryotes including zebra fish, where the gene product has been implicated in polycystic kidney disease. Western blot analysis and immunofluorescence with antibodies against recombinant TbLRTP indicate that the protein is expressed throughout the trypanosome life cycle and localizes to distal zones of the basal bodies. Overexpression and RNA interference demonstrate that TbLRTP is important for faithful basal body duplication and flagellum biogenesis. Expression of excess TbLRTP suppresses new flagellum assembly, while reduction of TbLRTP protein levels often results in the biogenesis of additional flagellar axonemes and paraflagellar rods that, most remarkably, are intracellular and fully contained within the cytoplasm. The mutant flagella are devoid of membrane and are often associated with four microtubules in an arrangement similar to that observed in the normal flagellar attachment zone. Aberrant basal body and flagellar biogenesis in TbLRTP mutants also influences cell size and cytokinesis. These findings demonstrate that TbLRTP suppresses basal body replication and subsequent flagellar biogenesis and indicate a critical role for the LRTP family of proteins in the control of the cell cycle. These data further underscore the role of aberrant flagellar biogenesis as a disease mechanism.

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