Identification of fibril-like tertiary contacts in soluble monomeric α-synuclein

Structural conversion of the presynaptic, intrinsically disordered protein α-synuclein into amyloid fibrils underlies neurotoxicity in Parkinson's disease. The detailed mechanism by which this conversion occurs is largely unknown. Here, we identify a discrete pattern of transient tertiary interactions in monomeric α-synuclein involving amino acid residues that are, in the fibrillar state, part of β-strands. Importantly, this pattern of pairwise interactions does not correspond to that found in the amyloid state. A redistribution of this network of fibril-like contacts must precede aggregation into the amyloid structure.Fil: Esteban Martin, Santiago. Barcelona Supercomputing Center. Research Programme in Computational Biology; EspañaFil: Silvestre Ryan, Jordi. Institute for Research in Biomedicine. Research Programme in Computational Biology; EspañaFil: Bertoncini, Carlos Walter. Institute for Research in Biomedicine. Research Programme in Computational Biology; España. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Salvatella, Xavier. Institute for Research in Biomedicine. Research Programme in Computational Biology; España. Institució Catalana de Recerca i Estudis Avançats; Españ

Design Archives: Sustainable Solutions for Young Designers in Valencia, Spain

Design education is practical and theoretical; however, it does not usually include the study of cultural heritage. Nonetheless, relations with academia have been strong since the 18th century, when the need to educate designers spread across the continent to improve design and make it competitive in the market. In this paper, we recover that spirit and act as mediators between heritage and young people to create links and preserve cultural heritage. A case study was conducted at the Public Valencian Design School with 31 product design students. The methodology applied was based on iterative processes that allowed students to discover design and silk heritage when they proposed innovative ways of approaching it. A qualitative survey was used to evaluate the case study. The results showed that students increased their appreciation for cultural heritage (by more than 90%) as well as their willingness to preserve it and reuse it in their future creations. Collaboration between cultural heritage and design might foster sustainable conservation and mark the future steps of ongoing collaboration

An Adhesive Peptide from the C-Terminal Domain of α-Synuclein for Single-Layer Adsorption of Nanoparticles onto Substrates

The two-dimensional (2D) homogeneous assembly of nanoparticle monolayer arrays onto a broad range of substrates constitutes an important challenge for chemistry, nanotechnology, and material science. α-Synuclein (αS) is an intrinsically disordered protein associated with neuronal protein complexes and has a high degree of structural plasticity and chaperone activity. The C-terminal domain of αS has been linked to the noncovalent interactions of this protein with biological targets and the activity of αS in presynaptic connections. Herein, we have systematically studied peptide fragments of the chaperone-active C-terminal sequence of αS and identified a 17-residue peptide that preserves the versatile binding nature of αS. Attachment of this short peptide to gold nanoparticles afforded colloidally stable nanoparticle suspensions that allowed the homogeneous 2D adhesion of the conjugates onto a wide variety of surfaces, including the formation of crystalline nanoparticle superlattices. The peptide sequence and the strategy reported here describe a new adhesive molecule for the controlled monolayer adhesion of metal nanoparticles and sets a stepping-stone toward the potential application of the adhesive properties of αSThis work was partially supported by the Spanish Agencia Estatal de Investigación (AEI) [BIO2015-70092-R, SAF2017-89890-R], the Xunta de Galicia (ED431C 2017/25, 2016-AD031, AGAUR (2017 SGR 324), and Centro Singular de Investigación de Galicia accreditation 2016–2019, ED431G/09), the ISCIII (COV20/00297), and the European Union (European Regional Development Fund – ERDF). X.S. acknowledges funding from the ERC (CONCERT-648201). IRB Barcelona is the recipient of a Severo Ochoa Award (Government of Spain). J.M. received a Ramón y Cajal (RYC-2013-13784), an ERC Starting Grant (DYNAP-677786), and a Young Investigator Grant from the HFSP (RGY0066/2017)S

Structure-Free Validation of Residual Dipolar Coupling and Paramagnetic Relaxation Enhancement Measurements of Disordered Proteins.

Residual dipolar couplings (RDCs) and paramagnetic relaxation enhancements (PREs) have emerged as valuable parameters for defining the structures and dynamics of disordered proteins by nuclear magnetic resonance (NMR) spectroscopy. Procedures for their measurement, however, may lead to conformational perturbations because of the presence of the alignment media necessary for recording RDCs, or of the paramagnetic groups that must be introduced for measuring PREs. We discuss here experimental methods for quantifying these effects by considering the case of the 40-residue isoform of the amyloid β peptide (Aβ40), which is associated with Alzheimer's disease. By conducting RDC measurements over a range of concentrations of certain alignment media, we show that perturbations arising from transient binding of Aβ40 can be characterized, allowing appropriate corrections to be made. In addition, by using NMR experiments sensitive to long-range interactions, we show that it is possible to identify relatively nonperturbing sites for attaching nitroxide radicals for PRE measurements. Thus, minimizing the conformational perturbations introduced by RDC and PRE measurements should facilitate their use for the rigorous determination of the conformational properties of disordered proteins.This is the author accepted manuscript. The final version is available from ACS via http://dx.doi.org/10.1021/acs.biochem.5b0067

Sequence Context Influences the Structure and Aggregation Behavior of a PolyQ Tract

Expansions of polyglutamine (polyQ) tracts in nine different proteins cause a family of neurodegenerative disorders called polyQ diseases. Because polyQ tracts are potential therapeutic targets for these pathologies there is great interest in characterizing the conformations that they adopt and in understanding how their aggregation behavior is influenced by the sequences flanking them. We used solution NMR to study at single-residue resolution a 156-residue proteolytic fragment of the androgen receptor that contains a polyQ tract associated with the disease spinobulbar muscular atrophy, also known as Kennedy disease. Our findings indicate that a Leu-rich region preceding the polyQ tract causes it to become α-helical and appears to protect the protein against aggregation, which represents a new, to our knowledge, mechanism by which sequence context can minimize the deleterious properties of these repetitive regions. Our results have implications for drug discovery for polyQ diseases because they suggest that the residues flanking these repetitive sequences may represent viable therapeutic targets

EPI-001, A Compound Active against Castration-Resistant Prostate Cancer, Targets Transactivation Unit 5 of the Androgen Receptor

ACKNOWLEDGEMENTS We thank J. M. Valverde (IRB) as well as the NMR facilities of the University of Barcelona (CCiT UB) and the Instituto de Química Física Rocasolano (IQFR, CSIC) for their assistance in, respectively, protein production and NMR. This work was supported by IRB, ICREA (X.S.), Obra Social “la Caixa” (Fellowship to E.D.M. and CancerTec grants to X.S.) MICINN (CTQ2009-08850 to X.S.), MINECO (BIO2012-31043 to X.S.; CTQ2014-56361-P to A.R), Marató de TV3 (102030 to X.S. and 102031 to E.E.P) the COFUND programme of the European Commission (C.T.W.P., A. R. and X.S.), the European Research Council (CONCERT, contract number 648201, to X.S.), the Ramón y Cajal program of MICINN (RYC-2011-07873 to C.W.B.) the Serra Hunter Programme (E.E.P.) and AGAUR (SGR-2014-56RR14 to E.E.P). IRB Barcelona is the recipient of a Severo Ochoa Award of Excellence from MINECO (Government of Spain)Peer reviewedPostprin

Hsp70 Oligomerization Is Mediated by an Interaction between the Interdomain Linker and the Substrate-Binding Domain

Oligomerization in the heat shock protein (Hsp) 70 family has been extensively documented both in vitro and in vivo, although the mechanism, the identity of the specific protein regions involved and the physiological relevance of this process are still unclear. We have studied the oligomeric properties of a series of human Hsp70 variants by means of nanoelectrospray ionization mass spectrometry, optical spectroscopy and quantitative size exclusion chromatography. Our results show that Hsp70 oligomerization takes place through a specific interaction between the interdomain linker of one molecule and the substrate-binding domain of a different molecule, generating dimers and higher-order oligomers. We have found that substrate binding shifts the oligomerization equilibrium towards the accumulation of functional monomeric protein, probably by sequestering the helical lid sub-domain needed to stabilize the chaperone: substrate complex. Taken together, these findings suggest a possible role of chaperone oligomerization as a mechanism for regulating the availability of the active monomeric form of the chaperone and for the control of substrate binding and release. © 2013 Aprile et al.FAA was recipient of a graduate fellowship from the Italian Ministry of Education, University and Research. AD is grateful for support from Murray Edwards College, Cambridge, through a Junior Research Fellowship. FS is a Sir Henry Wellcome Fellow. CR acknowledges financial support by the Spanish Ministry of Health according to the 'Plan Nacional de I+D+I 2008-2011', through ISCIII with cofunding by FEDER (CP10/00527). JLPB is a Royal Society University Research Fellow. FAA and PT are grateful for support from Regione Lombardia (NEDD and >Network Tecnologico integrato per lo studio proteomico e trascrittomico di malattie neurodegenerative correlate a deposizioni di amiloidi>). CMD acknowledges support from BBSRC (BB/E019927/1), the Wellcome Trust (094425/Z/10/Z), the European Commission (project LSHM-CT-2006-037525). NC acknowledges support from Human Frontiers Science Program (HFSP) through a Long-term Fellowship (LT000795/2009).Peer Reviewe

hnRNPDL phase separation is regulated by alternative splicing and disease-causing mutations accelerate its aggregation

Altres ajuts: .V. acknowledges funding from ICREA (ICREA-Academia 2016). IRB Barcelona is the recipient of a Severo Ochoa Award of Excellence from MINECO (government of Spain). C.B. acknowledges funding from "Ministerio de Educación y Formación ProfesionalPrion-like proteins form multivalent assemblies and phase separate into membraneless organelles. Heterogeneous ribonucleoprotein D-like (hnRNPDL) is a RNA-processing prion-like protein with three alternative splicing (AS) isoforms, which lack none, one, or both of its two disordered domains. It has been suggested that AS might regulate the assembly properties of RNA-processing proteins by controlling the incorporation of multivalent disordered regions in the isoforms. This, in turn, would modulate their activity in the downstream splicing program. Here, we demonstrate that AS controls the phase separation of hnRNPDL, as well as the size and dynamics of its nuclear complexes, its nucleus-cytoplasm shuttling, and amyloidogenicity. Mutation of the highly conserved D378 in the disordered C-terminal prion-like domain of hnRNPDL causes limb-girdle muscular dystrophy 1G. We show that D378H/N disease mutations impact hnRNPDL assembly properties, accelerating aggregation and dramatically reducing the protein solubility in the muscle of Drosophila, suggesting a genetic loss-of-function mechanism for this muscular disorde

ZPD-2, a small compound that inhibits α-synuclein amyloid aggregation and its seeded polymerization

Altres ajuts: SV was supported by the ICREA (ICREA-Academia 2015) and the Fundación La Marató de TV3 (Ref. 20144330). JavS was supported by the Gobierno de Aragón (E45_17R). ED was supported by the Instituto de Salud Carlos III (PH613883/ERDF/ESF).α-Synuclein (α-Syn) forms toxic intracellular protein inclusions and transmissible amyloid structures in Parkinson's disease (PD). Preventing α-Syn self-assembly has become one of the most promising approaches in the search for disease-modifying treatments for this neurodegenerative disorder. Here, we describe the capacity of a small molecule (ZPD-2), identified after a high-throughput screening, to inhibit α-Syn aggregation. ZPD-2 inhibits the aggregation of wild-type α-Syn and the A30P and H50Q familial variants in vitro at substoichiometric compound:protein ratios. In addition, the molecule prevents the spreading of α-Syn seeds in protein misfolding cyclic amplification assays. ZPD-2 is active against different α-Syn strains and blocks their seeded polymerization. Treating with ZPD-2 two different PD Caenorhabditis elegans models that express α-Syn either in muscle or in dopaminergic (DA) neurons substantially reduces the number of α-Syn inclusions and decreases synuclein-induced DA neurons degeneration. Overall, ZPD-2 is a hit compound worth to be explored in order to develop lead molecules for therapeutic intervention in PD

Hsp70 and Hsp40 inhibit an inter-domain interaction necessary for transcriptional activity in the androgen receptor.

Molecular chaperones such as Hsp40 and Hsp70 hold the androgen receptor (AR) in an inactive conformation. They are released in the presence of androgens, enabling transactivation and causing the receptor to become aggregation-prone. Here we show that these molecular chaperones recognize a region of the AR N-terminal domain (NTD), including a FQNLF motif, that interacts with the AR ligand-binding domain (LBD) upon activation. This suggests that competition between molecular chaperones and the LBD for the FQNLF motif regulates AR activation. We also show that, while the free NTD oligomerizes, binding to Hsp70 increases its solubility. Stabilizing the NTD-Hsp70 interaction with small molecules reduces AR aggregation and promotes its degradation in cellular and mouse models of the neuromuscular disorder spinal bulbar muscular atrophy. These results help resolve the mechanisms by which molecular chaperones regulate the balance between AR aggregation, activation and quality control