Characterization of the AhR−hsp90−XAP2 Core Complex and the Role of the Immunophilin-Related Protein XAP2 in AhR Stabilization†

Biochemistry ◽  
1999 ◽  
Vol 38 (28) ◽  
pp. 8907-8917 ◽  
Author(s):  
Brian K. Meyer ◽  
Gary H. Perdew
Keyword(s):  
Related Protein ◽  
Core Complex

Identification and Partial Characterization of Fanconi Anemia Associated Polypeptides (FAAPs) Using a Versatile Multiprotein-Complex Purification Method.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 989-989 ◽  
Author(s):  
Abdullah M. Ali ◽  
Thiyam R. Singh ◽  
Ruhikanta A. Meetei
Keyword(s):  
Mass Spectrometry ◽  
Cell Lines ◽  
Fanconi Anemia ◽  
Hela Cells ◽  
Affinity Purification ◽  
Gene Products ◽  
Core Complex ◽  
Purification Method

Abstract Fanconi Anemia (FA) is an autosomal recessive and X-linked disorder characterized by congenital abnormalities, progressive bone marrow failure, and a high incidence of hematological (acute leukemia) and non-hematological malignancies (squamous cell carcinomas of the head and neck or gynecologic system). FA is genetically heterogeneous disease and to date 12 complementation groups are known of which 11 gene products have been identified (FANC- A, B, C, D1, D2, E, F, G, J, L, M). Eight of the FA gene products, FANCA, FANCB, FANC, FANCE, FANCF, FANCG, FANCL and FANCM form a multiprotein FA core complex. This complex is required for the monoubiquitination of FANCD2 upon DNA damage by various genotoxic agents. The other two FA proteins; FANCD1/BRCA2 and FANCJ are believed to act “downstream” of FANCD2. In order to understand the role of FA proteins in DNA repair pathway it is necessary to find all the FA genes and their interacting partners. We have established a two-step purification method using 6XHis and FLAG tags for the biochemical and functional characterization of the FA core complex proteins. In an attempt to isolate interacting partners of FANCM and FANCL proteins; we have established two different HeLa cell lines; HeLa-HF-FANCM and HeLa-HF-FANCL, stably expressing HF-FANCM and HF-FANCL recombinant proteins respectively. Two step affinity purification was carried out to isolate the complexes from the extracts prepared from stable cell lines. Two polypeptides, namely, FAAP16 and FAAP100 were identified by mass-spectrometry as major interacting partners of FANCM and FANCL respectively. The interaction of FAAP16 and FAAP100 with other FA core complex proteins was confirmed by reciprocal affinity purification coupled mass-spectrometry using HeLa cells stably expressing HF-FAAP16 and HF-FAAP100 proteins. Furthermore, suppression of FAAP16 and FAAP100 in HeLa cells using siRNA resulted in a reduced MMC-induced FANCD2 monoubiquitination. Studies are being carried out to understand the precise role of these proteins in the FA core complex. These data suggest additional proteins interact with FA core complex members and demonstrate the utility of the purification method in delineating interacting proteins involved in FA.

scholarly journals Structural characterization of human Vaccinia-Related Kinases (VRK) bound to small-molecule inhibitors identifies different P-loop conformations

2017 ◽  
Author(s):  
Rafael M. Couñago ◽  
Charles K. Allerston ◽  
Pavel Savitsky ◽  
Hatylas Azevedo ◽  
Paulo H. Godoi ◽  
...  
Keyword(s):  
Broad Spectrum ◽  
Related Protein ◽  
Chemical Probes ◽  
Cellular Processes ◽  
Starting Point ◽  
Loop Conformations ◽  
Potential Use ◽  
Specific Inhibitors

ABSTRACTThe human genome encodes two active Vaccinia-related protein kinases (VRK), VRK1 and VRK2. These proteins have been implicated in a number of cellular processes and linked to a variety of tumors. However, understanding the cellular role of VRKs and establishing their potential use as targets for therapeutic intervention has been limited by the lack of tool compounds that can specifically modulate the activity of these kinases in cells. Here we identified BI-D1870, a dihydropteridine inhibitor of RSK kinases, as a promising starting point for the development of chemical probes targeting the active VRKs. We solved co-crystal structures of both VRK1 and VRK2 bound to BI-D1870 and of VRK1 bound to two broad-spectrum inhibitors. These structures revealed that both VRKs can adopt a P-loop folded conformation, which is stabilized by different mechanisms on each protein. Based on these structures, we suggest modifications to the dihydropteridine scaffold that can be explored to produce potent and specific inhibitors towards VRK1 and VRK2.

Heterologous expression and initial characterization of recombinant RbcX protein from Thermosynechococcus elongatus BP-1 and the role of RbcX in RuBisCO assembly.

2008 ◽  
Vol 55 (4) ◽  
pp. 777-785 ◽  
Author(s):  
Miroslaw Tarnawski ◽  
Beata Gubernator ◽  
Piotr Kolesinski ◽  
Andrzej Szczepaniak
Keyword(s):  
Soluble Fraction ◽  
Core Complex ◽  
Functional Studies ◽  
Initial Characterization ◽  
Thermophilic Organism ◽  
Dimeric Form ◽  
Rbcs Genes ◽  
Rubisco Subunits

In the cyanobacterial RuBisCO operon from Thermosynechococcus elongatus the rbcX gene is juxtaposed and cotranscribed with the rbcL and rbcS genes which encode large and small RuBisCO subunits, respectively. It has been suggested that the rbcX position is not random and that the RbcX protein could be a chaperone for RuBisCO. In this study, the RbcX protein from T. elongatus was overexpressed, purified and preliminary functional studies were conducted. The recombinant protein purified from Escherichia coli extracts was predominantly present in a soluble fraction in a dimeric form. Coexpression experiments have demonstrated that RbcX can mediate RbcL dimer (L(2)) formation, and that it is essential for the L(8) core complex assembly. This is the first characterization of the RbcX protein from a thermophilic organism.

Digital x-ray mapping of nanometer-size supported bimetallic catalysts

1988 ◽  
Vol 46 ◽  
pp. 530-531
Author(s):  
L. T. Germinario
Keyword(s):  
Background Radiation ◽  
Metal Cluster ◽  
Single Element ◽  
Beam Diameter ◽  
X Rays ◽  
X Ray ◽  
Major Interest ◽  
Induced Changes

Understanding the role of metal cluster composition in determining catalytic selectivity and activity is of major interest in heterogeneous catalysis. The electron microscope is well established as a powerful tool for ultrastructural and compositional characterization of support and catalyst. Because the spatial resolution of x-ray microanalysis is defined by the smallest beam diameter into which the required number of electrons can be focused, the dedicated STEM with FEG is the instrument of choice. The main sources of errors in energy dispersive x-ray analysis (EDS) are: (1) beam-induced changes in specimen composition, (2) specimen drift, (3) instrumental factors which produce background radiation, and (4) basic statistical limitations which result in the detection of a finite number of x-ray photons. Digital beam techniques have been described for supported single-element metal clusters with spatial resolutions of about 10 nm. However, the detection of spurious characteristic x-rays away from catalyst particles produced images requiring several image processing steps.

Consideraciones en torno a la reducción solipsista

1970 ◽  
Vol 11 ◽  
Author(s):  
Natalia Carolina Petrillo

ResumenEn el presente trabajo se intentará mostrar que la fenomenología no conduce a una postura solipsista. Para ello, se caracterizará en qué consiste el solipsismo. Luego, se intentará refutar a lo que se ha de llamar “solipsismo metafísico” y “solipsismo gnoseológico”, con el objetivo principal de poner de manifiesto el fundamento de motivación para la salida de la ficción solipsista.Palabras claves:Phenomenology – solipsim – empatía - HusserlAbstractWith the aim of showing that phenomenology does not lead in solipsism, I will first attempt a characterization of it. Then, I will attempt a refutation of the so-called “metaphysical” and “epistemological” solipsisms. Finally, the nature and role of Husserl´s solipsistic fiction is examined, and the grounds that motivate the overcoming of this standpoint are disclosed.key wordsFenomenología – solipsismo - empathy – Husserl

ART STUDIOS – A WAY TO DEVELOPE CHILDREN’S IMAGINATION

2020 ◽  
Vol 11 (1) ◽  
pp. 144-148
Author(s):  
Liuba Zlatkova ◽  
Keyword(s):  
Fairy Tale ◽  
Psychological Effects ◽  
Complete Product ◽  
The Arts ◽  
The Creation ◽  
Role Of Parents

The report describes the steps for creating a musical tale by children in the art studios of „Art Workshop“, Shumen. These studios are led by students volunteers related to the arts from pedagogical department of Shumen University, and are realized in time for optional activities in the school where the child studies. The stages of creating a complete product with the help of different arts are traced – from the birth of the idea; the creation of a fairy tale plot by the children; the characterization of the fairy-tale characters; dressing them in movement, song and speech; creating sets and costumes and creating a finished product to present on stage. The role of parents as a link and a necessary helper for children and leaders is also considered, as well as the positive psychological effects that this cooperation creates.

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