Identification of protein phosphatase 1 as a regulator of the LRRK2 phosphorylation cycle
In conclusion, our study reveals PP1 as the physiological LRRK2 phosphatase, responsible for LRRK2 dephosphorylation observed in PD mutant LRRK2 and after LRRK2 kinase inhibition. (Source: BJ Disease)
Source: BJ Disease - August 12, 2013 Category: Biochemistry Authors: E Lobbestael, J Zhao, I N. Rudenko, A Beylina, F Gao, J Wetter, M Beullens, M Bollen, M R. Cookson, V Baekelandt, R Nichols, J Taymans Tags: BJ Signal Source Type: research
Crystal structures of SCP2-thiolases of Trypanosomatidae, human pathogens causing widespread tropical diseases: the importance for catalysis of the cysteine of the unique HDCF loop
Thiolases are essential CoA dependent enzymes in lipid metabolism. Here we report on crystal structures of trypanosomal and leishmanial SCP2-thiolases. Trypanosomatidae cause various widespread, devastating (sub)-tropical diseases, for which adequate treatment is lacking. The structures reveal the unique geometry of the active site of this poorly characterized subfamily of thiolases. The key catalytic residues of the classical thiolases are two cysteines, functioning as a nucleophile and an acid/base, respectively. The latter cysteine is part of a CxG-motif. Interestingly, this cysteine is not conserved in SCP2-thiolases. ...
Source: BJ Disease - August 2, 2013 Category: Biochemistry Authors: R K. Harijan, T Kiema, M P. Karjalainen, N Janardan, M Murthy, M S. Weiss, P A.M. Michels, R K Wierenga Tags: BJ Biomolecules Source Type: research
Caspase-2 is essential for c-Jun transcriptional activation and Bim induction in neuron death
Neuronal apoptotic death generally requires de novo transcription, and activation of the transcription factor c-Jun has been shown to be necessary in multiple neuronal death paradigms. Caspase-2 has been implicated in death of neuronal and non-neuronal cells, but its relationship to transcriptional activation has not been clearly elucidated. Here, using two different neuronal apoptotic paradigms, β-amyloid treatment and NGF withdrawal, we examined the hierarchical role of caspase-2 activation in the transcriptional control of neuron death. Both paradigms induce rapid activation of caspase-2 as well as activation of ...
Source: BJ Disease - July 1, 2013 Category: Biochemistry Authors: Y Y. Jean, E M Ribe, M Pero, M Moskalenko, Z Iqbal, L J Marks, L A Greene, C M. Troy Tags: BJ Disease Source Type: research
Epitope scanning indicates structural differences in brain-derived, monomeric and aggregated mutant prion proteins related to genetic prion diseases
Genetic Creutzfeldt-Jakob disease, Gerstmann-Sträussler-Scheinker syndrome, fatal familial insomnia, and prion protein cerebral amyloid angiopathy are clinically and neuropathologically distinct neurodegenerative diseases linked to mutations in the PRNP gene encoding the cellular prion protein (PrPC). How sequence variants of PRNP encode the information to specify these disease phenotypes is not known. It is suggested that each mutation produces a misfolded variant of PrPC with specific neurotoxic properties. However, structural studies of recombinant PrP did not detect major differences between wild-type and mutant...
Source: BJ Disease - June 28, 2013 Category: Biochemistry Authors: L Tapella, M Stravalaci, A Bastone, E Biasini, M Gobbi, R Chiesa Tags: BJ Biomolecules Source Type: research
Flavanoids Induce Expression of the Suppressor of Cytokine Signalling 3 (SOCS3) Gene and Suppress IL6- Activated Signal Transducer and Activator of Transcription 3 (STAT3) Activation in Vascular Endothelial Cells
The atherogenic cytokine interleukin-6 (IL6) induces pro-inflammatory gene expression in vascular endothelial cells (VECs) by activating the JAK/STAT3 signalling pathway, which is normally down-regulated by the STAT3-dependent induction of the E3 ubiquitin ligase component, SOCS3. Novel treatments based on the regulation of SOCS3 protein levels could therefore have value in the treatment of diseases with an inflammatory component, like atherosclerosis. To this end we carried out a screen of 1031 existing medicinal compounds to identify inducers of SOCS3 gene expression and identified the flavanoids, naringenin and flavone,...
Source: BJ Disease - June 19, 2013 Category: Biochemistry Authors: J Wiejak, J Dunlop, S P Mackay, S J Yarwood Tags: BJ Signal Source Type: research
A GPI anchor explains the unique biological features of the common NKG2D-ligand allele MICA*008
The human MICA gene, encoding a ligand for the NKG2D receptor, is highly polymorphic. A group of MICA alleles, named MICA 5.1 (prototype, MICA*008), produce a truncated protein due to a nucleotide insertion in the transmembrane domain. These alleles are very frequent in all the human populations studied and they have different biological properties, compared to full-length alleles, eg. recruitment into exosomes, which makes them very potent for downmodulating the NKG2D receptor in effector immune cells. Moreover, MICA*008 is not affected by viral immune evasion mechanisms that target other MICA alleles. Here we demonstrate...
Source: BJ Disease - June 18, 2013 Category: Biochemistry Authors: O Ashiru, S López-Cobo, L Fernández-Messina, S Pontes-Quero, R Pandolfi, H T. Reyburn, M Valés-Gomez Tags: BJ Disease Source Type: research
Copper chaperone Atox1 interacts with the metal-binding domain of Wilson disease protein in cisplatin detoxification.
Human copper transporters ATP7B and ATP7A have been implicated in tumor resistance to cisplatin, a widely used anticancer drug. Cisplatin binds to the copper-binding sites in the N-terminal domain of ATP7B, and this binding may be an essential step of cisplatin detoxification involving copper ATPases. Here we demonstrate that cisplatin and a related platinum drug carboplatin produce the same adduct upon reaction with metal-binding repeat 2 (MBD2), where platinum is bound to the side chains of cysteine residues in the CxxC copper-binding motif. This suggests the same mechanism for detoxification of both drugs by ATP7B. Plat...
Source: BJ Disease - June 11, 2013 Category: Biochemistry Authors: N V Dolgova, S Nokhrin, C H Yu, G N George, O Y Dmitriev Tags: BJ Disease Source Type: research
Roles of EXTL2, a member of EXT family of tumor suppressors, in liver injury and regeneration processes
The gene products of two members of the EXT gene family, EXT1 and EXT2, function together as a polymerase in the biosynthesis of heparan sulfate. EXTL2, one of the three EXT-like genes in the human genome that are homologous to EXT1 and EXT2, encodes a N-acetylhexosaminyltransferase. Recently, we have demonstrated that EXTL2 terminates chain elongation of glycosaminoglycans (GAGs), and thereby regulates GAG biosynthesis. The abnormal GAG biosynthesis caused by loss of EXTL2 had no effect on normal development or normal adult homeostasis. Therefore, we examined the role of EXTL2 in carbon tetrachloride (CCl4)-induced liver ...
Source: BJ Disease - June 4, 2013 Category: Biochemistry Authors: S Nadanaka, S Kagiyama, H Kitagawa Tags: BJ Disease Source Type: research
Multilevel functional and structural defects induced by two pathogenic mitochondrial tRNA mutations
Point mutations in human mitochondrial tRNAs (hmtRNAs) can cause various disorders such as chronic progressive external ophthalmoplegia (CPEO) and mitochondrial myopathy (MM). Mitochondrial tRNALeu , especially UUR isoacceptor is recognised as a hot spot for pathogenic mitochondrial DNA point mutations. Thus far, 40 mutations have been identified in hmtRNAsLeu. Here, we describe the wide range of impacts of two substitutions found in the TΨC-arms of two hmtRNAsLeu isoacceptors. The G52A substitution, corresponding to the pathogenic G12315A mutation in tRNALeu(CUN) and G3283A in tRNALeu(UUR), exhibited structural cha...
Source: BJ Disease - May 1, 2013 Category: Biochemistry Authors: M Wang, X Zhou, R Liu, Z Fang, M Zhou, G Eriani, E Wang Tags: BJ Biomolecules Source Type: research
Identification of the SV2-Protein Receptor Binding Site of Botulinum Neurotoxin Type E
The highly specific binding and uptake of botulinum neurotoxins (BoNT/A-G) into peripheral cholinergic motoneurons turns them into the most poisonous substances known. Interaction with gangliosides accumulates the neurotoxins on the plasma membrane and binding to a synaptic vesicle membrane protein leads to neurotoxin endocytosis. The synaptic vesicle (glyco-)protein 2 (SV2) mediates the uptake of BoNT/A and E, whereas synaptotagmin (Syt) is responsible for the endocytosis of BoNT/B and G. The Syt-binding site of the former was identified by co-crystallization and mutational analyses. Here we report the identification of t...
Source: BJ Disease - April 29, 2013 Category: Biochemistry Authors: S Mahrhold, J Strotmeier, C Garcia-Rodriguez, J Lou, J D. Marks, A Rummel, T Binz Tags: BJ Biomolecules Source Type: research
Decreased translation of Dio3 mRNA is associated with drug-induced hepatotoxicity.
Recent work has demonstrated the importance of post-transcriptional gene regulation in toxic responses. Here we used two rat models to investigate mRNA translation in the liver following xenobiotic-induced toxicity. By combining polysome profiling with genomic methodologies we were able to assess global changes in hepatic mRNA translation. Iodothyronine deiodinase, type III (Dio3) was identified as a gene that exhibited specific translational repression and had a functional role in a number of relevant canonical pathways. Western blot analysis indicated that this repression led to reduced Dio3 protein (D3) levels, enhanced...
Source: BJ Disease - April 16, 2013 Category: Biochemistry Authors: K M Dudek, L Suter, V M Darras, E L Marczylo, T W Gant Tags: BJ Gene Source Type: research
SUMOylation is a regulator of the translocation of Jak2 between nucleus and cytosol
Jak2 initiates the signal transduction of many cytokine receptors. We discovered that Jak2 is SUMOylated on multiple lysine residues by SUMO2/3 chains. Analysis of Jak2 mutants revealed that Jak2 SUMOylation depends on the presence of an active catalytic site. We used the growth hormone receptor to study the physiological relevance of Jak2 SUMOylation. Both GH stimulation and several other environmental stressors increased Jak2 SUMOylation. Cell fractionation showed that SUMOylated Jak2 is mainly present in the nucleus. The constitutively active V617F Jak2 mutant, implicated in myeloproliferative diseases, was highly SUMOy...
Source: BJ Disease - April 15, 2013 Category: Biochemistry Authors: M Sedek, G J. Strous Tags: BJ Signal Source Type: research
Comprehensive Characterization and Optimization of Leucine Rich Repeat Kinase 2 (LRRK2) Monoclonal Antibodies
Missense mutations in leucine-rich repeat kinase 2 (LRRK2) are a major cause of Parkinson’s disease (PD). Several antibodies against LRRK2 have been developed, but results using these polyclonal antibodies have varied widely leading to conflicting conclusions. To address this challenge, The Michael J. Fox Foundation for Parkinson’s Research generated a number of monoclonal antibodies targeting epitopes across the LRRK2 protein. Herein, we report optimized protocols and results for ten monoclonal antibodies for immunoblotting, immunohistochemistry, immunoprecipitation, and kinase activity assays, in rat, mouse...
Source: BJ Disease - April 5, 2013 Category: Biochemistry Authors: P Davies, K M Hinkle, N N Sukar, B Sepulveda, R Mesias, G Serrano, D R Alessi, T G Beach, D L Benson, C L White III, R M Cowell, S S Das, A B West, H L Melrose Tags: BJ Disease Source Type: research
Ebola virus VP35 induces high-level production of recombinant TPL-2 / ABIN-2 / NF-{kappa}B1 p105 complex in co-transfected HEK-293 cells
Activation of Protein Kinase R (PKR) by DNA plasmids decreases translation, and limits the amount of recombinant protein produced by transiently transfected HEK-293 cells. Co-expression with Ebola virus VP35, which blocked plasmid activation of PKR, substantially increased production of recombinant TPL-2/ABIN-2/NF-kB1 p105 complex. VP35 also increased expression of other co-transfected proteins, suggesting that VP35 could be employed generally to boost recombinant protein production by HEK-293 cells. (Source: BJ Disease)
Source: BJ Disease - April 4, 2013 Category: Biochemistry Authors: T Gantke, S Boussouf, J Janzen, N A Morrice, S Howell, E Mühlberger, S C Ley Tags: BJ Signal Source Type: research
Identification of the first synthetic inhibitors of the type II transmembrane serine protease TMPRSS2 suitable for inhibition of influenza virus activation
TMPRSS2 is a multidomain type II transmembrane serine protease that cleaves the surface glycoprotein hemagglutinin (HA) of influenza viruses with monobasic cleavage site, which is a prerequisite for virus fusion and propagation. Furthermore, it activates the fusion protein F of the human metapneumovirus and the spike protein S of the SARS coronavirus. Increased TMPRSS2 expression was also described in several tumor entities. Therefore, TMPRSS2 emerged as a potential target for drug design. The catalytic domain of TMPRSS2 was expressed in E. coli and used for an inhibitor screen with previously synthesized inhibitors of var...
Source: BJ Disease - March 25, 2013 Category: Biochemistry Authors: D Meyer, F Sielaff, M Hammami, E Böttcher-Friebertshäuser, W Garten, T Steinmetzer Tags: BJ ChemBio Source Type: research
