Journal of Biological Chemistry Impact Factor & Information

Publisher: American Society for Biochemistry and Molecular Biology, American Society for Biochemistry and Molecular Biology

Journal description

Complete content of the Journal of Biological Chemistry as of April 1995.

Current impact factor: 4.57

Impact Factor Rankings

2015 Impact Factor Available summer 2016
2014 Impact Factor 4.573
2013 Impact Factor 4.6
2012 Impact Factor 4.651
2011 Impact Factor 4.773
2010 Impact Factor 5.328
2009 Impact Factor 5.328
2008 Impact Factor 5.52
2007 Impact Factor 5.581
2006 Impact Factor 5.808
2005 Impact Factor 5.854
2004 Impact Factor 6.355
2003 Impact Factor 6.482
2002 Impact Factor 6.696
2001 Impact Factor 7.258
2000 Impact Factor 7.368
1999 Impact Factor 7.666
1998 Impact Factor 7.199
1997 Impact Factor 6.963
1996 Impact Factor 7.452
1995 Impact Factor 7.385
1994 Impact Factor 7.716
1993 Impact Factor 6.793
1992 Impact Factor 6.733

Impact factor over time

Impact factor

Additional details

5-year impact 4.69
Cited half-life >10.0
Immediacy index 0.89
Eigenfactor 0.54
Article influence 1.74
Website Journal of Biological Chemistry website
Other titles Journal of biological chemistry (Online), Journal of biological chemistry, JBC online, JBC
ISSN 1083-351X
OCLC 32808313
Material type Document, Periodical, Internet resource
Document type Internet Resource, Computer File, Journal / Magazine / Newspaper

Publisher details

American Society for Biochemistry and Molecular Biology

  • Pre-print
    • Author cannot archive a pre-print version
  • Post-print
    • Author cannot archive a post-print version
  • Restrictions
    • 12 months embargo
  • Conditions
    • Authors accepted peer-reviewed manuscript may be posted on an institutional repository
    • Publisher copyright and source must be acknowledged with set phrase: "This research was originally published in Journal Name. Author(s). Title. Journal Name. Year. Vol:pp-pp. © the American Society for Biochemistry and Molecular Biology"
    • On a non-profit server
    • Publisher's version/PDF cannot be used
  • Classification
    ​ white

Publications in this journal

  • [Show abstract] [Hide abstract]
    ABSTRACT: The melanocortin-2 (MC2) receptor is a G protein-coupled receptor that mediates responses to ACTH. The MC2 receptor acts in concert with an accessory protein (MRAP) that is absolutely required for ACTH binding and signaling. MRAP has a single transmembrane domain and forms a highly unusual anti-parallel homodimer that is stably associated with MC2 receptors at the plasma membrane. Despite the physiological importance of the interaction between the MC2 receptor and MRAP, there is little understanding of how the accessory protein works. The dual topology of MRAP has made it impossible to determine whether highly conserved and necessary regions of MRAP are required on the intracellular or extracellular face of the plasma membrane. The strategy used here was to fix the orientation of two anti-parallel MRAP molecules and then introduce inactivating mutations on one side of the membrane or the other. This was achieved by engineering proteins containing tandem copies of MRAP fused to the amino-terminus of the MC2 receptor. The data firmly establish that only the Nout copy of MRAP, oriented with critical segments on the extracellular side of the membrane, is essential. The transmembrane domain of MRAP is also required in only the Nout orientation. Finally, activity of MRAP-MRAP-MC2-receptor fusion proteins with inactivating mutations in either MRAP or the receptor is rescued by co-expression of free wild-type MRAP or free wild-type receptor. These results show that the basic MRAP/MRAP/receptor signaling unit forms higher order complexes and that these multimers signal.
    Journal of Biological Chemistry 10/2015; DOI:10.1074/jbc.M115.668491
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    ABSTRACT: Association studies have suggested that DISC1 (Disrupted-in-Schizophrenia-1) confers a genetic risk at the level of endophenotypes that underlies many major mental disorders. Despite the progress on understanding the significance of DISC1 at neural development, the mechanisms underlying DISC1 regulation of synaptic functions remain elusive. Since alterations in the cortical GABA system have been strongly linked to the pathophysiology of schizophrenia, one potential target of DISC1 that is critically involved in the regulation of cognition and emotion is the GABAA receptor. We found that cellular knockdown of DISC1 significantly reduced GABAAR-mediated synaptic and whole-cell current, while overexpression of wild-type DISC1, but not the C-terminal-truncated DISC1 (a schizophrenia-related mutant), significantly increased GABAAR currents in pyramidal neurons of prefrontal cortex. These effects were accompanied by DISC1-induced changes in surface GABAAR expression. Moreover, the regulation of GABAARs by DISC1 knockdown or overexpression depends on the microtubule motor protein kinesin-1 (KIF5). Our results suggest that DISC1 exerts an important impact on GABAergic inhibitory transmission by regulating KIF5/microtubule-based GABAAR trafficking in the cortex. Knowledge gained from this study would shed light on how DISC1 and the GABA system are mechanistically linked and how their interactions are critical for maintaining a normal mental state.
    Journal of Biological Chemistry 10/2015; DOI:10.1074/jbc.M115.656173
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    ABSTRACT: Alternative splicing diversifies mRNA transcripts in human cells. This sequence-driven process can be influenced greatly by mutations, even those that do not change the protein coding potential of the transcript. Synonymous mutations have been shown to alter gene expression through modulation of splicing, mRNA stability, and translation. Using a synonymous position mutation library in SMN1 exon 7, we show that 23% of synonymous mutations across the exon decrease exon inclusion, suggesting that nucleotide identity across the entire exon has been evolutionarily optimized to support a particular exon inclusion level. While phylogenetic conservation scores are insufficient to identify synonymous positions important for exon inclusion, an alignment of organisms filtered based on similar exon/intron architecture is highly successful. Although many of the splicing neutral mutations are observed to occur, none of the exon inclusion reducing mutants was found in the filtered alignment. Using the modified phylogenetic comparison as an approach to evaluate the impact on pre-mRNA splicing suggests that up to 45% of synonymous SNPs are likely to alter pre-mRNA splicing. These results demonstrate that coding and pre-mRNA splicing pressures co-evolve and that a modified phylogenetic comparison based on the exon/intron architecture is a useful tool in identifying splice altering SNPs.
    Journal of Biological Chemistry 10/2015; DOI:10.1074/jbc.M115.684035
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    ABSTRACT: The Aryl hydrocarbon Receptor (AhR), a regulator of xenobiotic toxicity, is a member of the eukaryotic Per-Arnt-Sim domain protein family of transcription factors. Recent evidence identified a novel AhR DNA recognition sequence called the non-consensus xenobiotic response element (NC-XRE). AhR binding to the NC-XRE in response to activation by the canonical ligand 2,3,7,8-tetrachlorodibenzo-p-dioxin, resulted in concomitant recruitment of Carbamoyl Phosphate Synthase 1 (CPS1) to the NC-XRE. Studies presented here demonstrate that CPS1 is a bona fide nuclear protein involved in homocitrullination (hcit), including a key lysine residue on histone H1 (H1K34hcit). H1K34hcit represents a hitherto unknown epigenetic mark implicated in enhanced gene expression of the peptidylarginine deiminase 2 gene, itself a chromatin modifying protein. Collectively, our data suggest that AhR activation promotes CPS1 recruitment to DNA enhancer sites in the genome resulting in a specific enzyme-independent post-translational modification (PTM) of the linker histone H1 protein (H1K34hcit), pivotal in altering local chromatin structure and transcriptional activation.
    Journal of Biological Chemistry 10/2015; DOI:10.1074/jbc.M115.678144
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    ABSTRACT: The Fanconi anemia protein PALB2, also known as FANCN, protects genome integrity by regulating DNA repair and cell cycle checkpoints. Exactly how PALB2 functions may be temporally coupled with detection and signaling of DNA damage is not known. Intriguingly, we found that PALB2 is transformed into a hyper-phosphorylated state in response to ionizing radiation (IR). IR treatment specifically triggered PALB2 phosphorylation at Ser157 and Ser376 in manners that required the master DNA Damage Response (DDR) kinase Ataxia telangiectasia mutated (ATM), revealing potential mechanistic links between PALB2 and the ATM-dependent DDRs. Consistently, dysregulated PALB2 phosphorylation resulted in sustained activation of DDRs. Full-blown PALB2 phosphorylation also required the breast and ovarian susceptible gene product BRCA1, highlighting important roles of the BRCA1-PALB2 interaction in orchestrating cellular responses to genotoxic stress. In summary, our phosphorylation analysis of tumour suppressor protein PALB2 uncovers new layers of regulatory mechanisms in the maintenance of genome stability and tumor suppression.
    Journal of Biological Chemistry 09/2015; DOI:10.1074/jbc.M115.672626
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    ABSTRACT: Angiotensin II type 1 receptor (AT1R) is the primary blood pressure regulator. AT1R blockers (ARBs) have been widely used in clinical settings as anti-hypertensive drugs, and share a similar chemical scaffold, although even minor variations can lead to distinct therapeutic efficacies towards cardiovascular etiologies. The structural basis for AT1R modulation by different peptide and non-peptide ligands has remained elusive. Here we report the crystal structure of the human AT1R in complex with an inverse agonist olmesartan (BenicarTM), a highly potent anti-hypertensive drug. Olmesartan is anchored to the receptor primarily by the residues Tyr351.39, Trp842.60, and Arg167ECL2, similar to the antagonist ZD7155, corroborating a common binding mode of different ARBs. Using docking simulations and site-directed mutagenesis we identified specific interactions between AT1R and different ARBs, including olmesartan derivatives with inverse agonist, neutral antagonist or agonist activities. We further observed that the mutation Asn1113.35Ala in the putative sodium-binding site affects binding of the endogenous peptide agonist Angiotensin II, but not the β-arrestin-biased peptide TRV120027.
    Journal of Biological Chemistry 09/2015; DOI:10.1074/jbc.M115.689000
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    ABSTRACT: Neurogenesis involves generation of new neurons through finely tuned multistep processes such as neural stem cell's (NSC) proliferation, migration, differentiation, and integration into existing neuronal circuitry in the dentate gyrus of the hippocampus and sub-ventricular zone (SVZ). Adult hippocampal neurogenesis is involved in cognitive functions and altered in various neurodegenerative disorders including Alzheimer's disease (AD). Ethosuximide (ETH), an anticonvulsant drug is used for the treatment of epileptic seizure. However, the effects of ETH on adult hippocampal neurogenesis and underlying cellular and molecular mechanism(s) are still elusive. Herein, we studied the effects of ETH on rat multipotent NSC proliferation and neuronal differentiation, and adult hippocampal neurogenesis in an amyloid beta (Aβ) toxin induced rat model of AD like phenotypes. ETH potently induced NSC proliferation and neuronal differentiation in the hippocampal derived NSC in vitro. ETH enhanced NSC proliferation and neuronal differentiation, and reduced Aβ toxin mediated toxicity and neurodegeneration, leading to behavioral recovery in rat AD model. ETH inhibited Aβ mediated suppression of neurogenic and Akt-Wnt/β-catenin pathway gene's expression in the hippocampus. ETH activated the PI3K/Akt and Wnt/β-catenin transduction pathways that are known to be involved in the regulation of neurogenesis. Inhibition of the PI3K/Akt and Wnt/β-catenin pathways effectively blocked the mitogenic and neurogenic effects of ETH. In silico molecular target prediction docking studies suggest that ETH interacts with Akt, Dkk-1 and GSK-3β. Our findings suggest that ETH stimulates NSC proliferation and differentiation in vitro and adult hippocampal neurogenesis via the PI3K/Akt and Wnt/β-catenin signaling.
    Journal of Biological Chemistry 09/2015; DOI:10.1074/jbc.M115.652586
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    ABSTRACT: Kaposi's sarcoma-associated herpesvirus (KSHV) has a causative role in several human malignancies. KSHV latency-associated nuclear antigen (LANA) mediates persistence of viral episomes in latently infected cells. LANA mediates KSHV DNA replication and segregates episomes to progeny nuclei. The structure of the LANA DNA binding domain was recently solved, revealing a positive electrostatic patch opposite the DNA binding surface, which is the site of BET protein binding. Here, we investigate the functional role of the positive patch in LANA mediated episome persistence. As expected, LANA mutants with alanine or glutamate substitutions in the central, peripheral, or lateral portions of the positive patch maintained the ability to bind DNA by EMSA. However, all of the substitution mutants were deficient for LANA DNA replication and episome maintenance. Mutation of the peripheral region generated the largest deficiencies. Despite these deficiencies, all positive patch mutants concentrated to dots along mitotic chromosomes in cells containing episomes, similar to LANA. The central and peripheral mutants, but not the lateral mutants, were reduced for BET protein interaction as assessed by co-immunoprecipitation. However, defects in BET protein binding were independent of episome maintenance function. Overall, the reductions in episome maintenance closely correlated with DNA replication deficiencies, suggesting that the replication defects account for the reduced episome persistence. Therefore, the electrostatic patch exerts a key role in LANA mediated DNA replication and episome persistence, and may act through a host cell partner(s) other than a BET protein or by inducing specific structures or complexes.
    Journal of Biological Chemistry 09/2015; DOI:10.1074/jbc.M115.674622
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    ABSTRACT: The photoreceptor-specific glycoprotein retinal degeneration slow (RDS, also called PRPH2) is necessary for the formation of rod and cone outer segments. Mutations in RDS cause rod and cone dominant retinal disease, and it is well established that both cell types have different requirements for RDS. However, the molecular mechanisms for this difference remain unclear. Although RDS glycosylation is highly conserved, previous study revealed no apparent function for the glycan in rods. In light of the highly conserved nature of RDS glycosylation we hypothesized that it is important for RDS function in cones, and could underlie part of the differential requirement for RDS in the two photoreceptor subtypes. We generated a knockin mouse expressing RDS without the N-glycosylation site (N229S). Normal levels of RDS and the unglycosylated RDS binding partner rod outer segment membrane protein-1 (ROM-1) were found in N229S retinas however cone electroretinogram responses were decreased by 40% at 6 months of age. Since cones make up only 3-5% of photoreceptors in the wild-type background, N229S mice were crossed into the nrl(-/-) background (in which all rods are converted to cone-like cells) for biochemical analysis. In N229S/nrl(-/-) retinas, RDS and ROM-1 levels were decreased by ~60% each. These data suggest that glycosylation of RDS is required for RDS function or stability in cones, a difference that may be due to extracellular vs. intradiscal localization of the RDS glycan in cones vs. rods.
    Journal of Biological Chemistry 09/2015; DOI:10.1074/jbc.M115.683698
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    ABSTRACT: About two-thirds of human congenital heart disease (CHD) involves second heart field (SHF) derived structures. Histone-modifying enzymes, histone deacetylases (HDACs), regulate the epigenome; however, their functions within the second heart field remain elusive. Here we demonstrate that histone deacetylase 3 (Hdac3) orchestrates epigenetic silencing of Tgfβ1, a causative factor in CHD pathogenesis, in a deacetylase-independent manner to regulate development of SHF-derived structures. In murine embryos lacking Hdac3 in the SHF, increased Tgfβ1 bioavailability is associated with ascending aortic dilatation, outflow tract malrotation, overriding aorta, double outlet right ventricle, aberrant semilunar valve development, bicuspid aortic valve, ventricular septal defects, and embryonic lethality. Activation of Tgfβ signaling causes aberrant endothelial-to-mesenchymal transition (EndMT) and altered extracellular matrix homeostasis in Hdac3-null outflow tracts and semilunar valves and pharmacological inhibition of Tgfβ rescues these defects. Hdac3 recruits components of PRC2 complex, methyltransferase Ezh2, Eed, and Suz12 to the Ncor complex to enrich trimethylation of lys27 on histone H3 at the Tgfβ1 regulatory region and thereby maintains epigenetic silencing of Tgfβ1 specifically within the SHF-derived mesenchyme. Wild-type Hdac3 or catalytically-inactive Hdac3 expression rescue aberrant EndMT and epigenetic silencing of Tgfβ1 in Hdac3-null outflow tracts and semilunar valves. These findings reveal that epigenetic dysregulation within the SHF is a predisposing factor for CHD.
    Journal of Biological Chemistry 09/2015; DOI:10.1074/jbc.M115.684753
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    ABSTRACT: Functional and deep sequencing studies have combined to demonstrate the involvement of APOBEC3B in cancer mutagenesis. APOBEC3B is a single-stranded DNA cytosine deaminase that functions normally as a nuclear-localized restriction factor of DNA-based pathogens. However, it is overexpressed in cancer cells and elicits an intrinsic preference for 5'-TC motifs in single-stranded DNA, which is the most frequently mutated dinucleotide in breast, head/neck, lung, bladder, cervical, and several other tumor types. In many cases, APOBEC3B mutagenesis accounts for the majority of both dispersed and clustered (kataegis) cytosine mutations. Here, we report the first structures of the APOBEC3B catalytic domain in multiple crystal forms. These structures reveal a tightly closed active site conformation and suggest that substrate accessibility is regulated by adjacent flexible loops. Residues important for catalysis are identified by mutation analyses and the results provide insights into the mechanism of target site selection. We also report a nucleotide (dCMP) bound crystal structure that informs a multi-step model for binding single-stranded DNA. Overall, these high-resolution crystal structures provide a framework for further mechanistic studies and the development of novel anti-cancer drugs to inhibit this enzyme, dampen tumor evolution, and minimize adverse outcomes such as drug resistance and metastasis.
    Journal of Biological Chemistry 09/2015; DOI:10.1074/jbc.M115.679951
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    ABSTRACT: The membrane sector (Vo) of the proton pumping vacuolar ATPase (V-ATPase; V1Vo-ATPase) from Saccharomyces cerevisiae was purified to homogeneity and its structure was characterized by electron microscopy (EM) of single molecules and two-dimensional (2-D) crystals. Projection images of negatively stained Vo 2-D crystals showed a ring like structure with a large asymmetric mass at the periphery of the ring. A cryo EM reconstruction of Vo from single particle images showed subunits a and d in close contact on the cytoplasmic side of the proton channel. A comparison of 3-D reconstructions of free Vo and Vo as part of holo V1Vo revealed that the cytoplasmic N-terminal domain of subunit a (aNT) must undergo a large conformational change upon enzyme disassembly or (re)assembly from Vo, V1 and subunit C. Isothermal titration calorimetry using recombinant subunit d and aNT revealed that the two proteins bind each other with a Kd of ~ 5 μM. Treatment of purified Vo sector with lyso 1-palmitoyl phosphatidylglycerol (LPPG) resulted in selective release of subunit d, allowing purification of a VoΔd complex. Passive proton translocation assays revealed that both Vo and VoΔd are impermeable to protons. We speculate that the structural change in subunit a upon release of V1 from Vo during reversible enzyme dissociation plays a role in blocking passive proton translocation across free Vo and that the interaction between aNT and d seen in free Vo functions to stabilize the Vo sector for efficient reassembly of V1Vo.
    Journal of Biological Chemistry 09/2015; DOI:10.1074/jbc.M115.662494
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    ABSTRACT: Melanopsins play a key role in non-visual photoreception in mammals. Their close phylogenetic relationship to the photopigments in invertebrate visual cells suggests they have evolved to acquire molecular characteristics that are more suited for their non-visual functions. Here we set out to identify such characteristics, by comparing the molecular properties of mammalian melanopsin to those of invertebrate melanopsin and visual pigment. Our data show that the Schiff base linking the chromophore retinal to the protein is more susceptive to spontaneous cleavage in mammalian melanopsins. We also find this stability is highly diversified between mammalian species, being particularly unstable for human melanopsin. Through mutagenesis analyses, we find that this diversified stability is mainly due to parallel amino acid substitutions in extra-cellular regions. We propose that the different stability of the retinal attachment in melanopsins may contribute to functional tuning of non-visual photoreception in mammals.
    Journal of Biological Chemistry 09/2015; DOI:10.1074/jbc.M115.666305
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    ABSTRACT: Mitochondrial dysfunction is considered crucial for NLRP3 inflammasome activation partly through its release of mitochondrial toxic products such as mitochondrial ROS (mROS) and mitochondrial DNA (mtDNA). While previous studies have shown that classical NLRP3-activating stimulations lead to mROS generation and mtDNA release, it remains poorly understood whether and how mitochondrial damage-derived factors may contribute to NLRP3 inflammasome activation. Here, we demonstrate that impairment of the mitochondrial electron transport chain by rotenone licenses NLRP3 inflammasome activation only upon costimulation with ATP, but not with nigericin or alum. Rotenone-induced priming of NLRP3 in the presence of ATP triggered the formation of speck-like NLRP3 or ASC aggregates and the association of NLRP3 with ASC, resulting in NLRP3-dependent caspase-1 activation. Mechanistically, rotenone confers a priming signal for NLRP3 inflammasome activation only in the context of aberrant high-grade, but not low-grade, mROS production and mitochondrial hyperpolarization. By contrast, rotenone/ATP-mediated mtDNA release and mitochondrial depolarization are likely to be merely an indication of mitochondrial damage rather than triggering factors for NLRP3 inflammasome activation. Our results provide a molecular insight into the selective contribution made by mitochondrial dysfunction to the NLRP3 inflammasome pathway.
    Journal of Biological Chemistry 09/2015; DOI:10.1074/jbc.M115.667063
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    ABSTRACT: For long, protein transport into the extracellular space was believed to strictly depend on signal peptide mediated translocation into the lumen of the endoplasmic reticulum. More recently, this view has been challenged and the molecular mechanisms of unconventional secretory processes are beginning to emerge. Here, we focus on unconventional secretion of fibroblast growth factor 2 (FGF2), a secretory mechanism that is based upon direct protein translocation across plasma membranes. Through a combination of genome-wide RNAi screening approaches and biochemical reconstitution experiments, the basic machinery of FGF2 secretion was identified and validated. This includes the integral membrane protein ATP1A1, the phosphoinositide PI(4,5)P2, Tec kinase as well as membrane proximal heparan sulfate proteoglycans on cell surfaces. Hallmarks of unconventional secretion of FGF2 are (i) Sequential molecular interactions with the inner leaflet along with Tec kinase dependent tyrosine phosphorylation of FGF2, (ii) PI(4,5)P2-dependent oligomerization and membrane pore formation and (iii) Extracellular trapping of FGF2 mediated by heparan sulfate proteoglycans on cell surfaces. Here we discuss new developments regarding this process including the mechanism of FGF2 oligomerization during membrane pore formation, the functional role of ATP1A1 in FGF2 secretion and the possibility that other proteins secreted by unconventional means make use of a similar mechanism to reach the extracellular space. Furthermore, given the prominent role of extracellular FGF2 in tumor induced angiogenesis, we will discuss possibilities to develop highly specific inhibitors of FGF2 secretion, a novel approach that may give way for lead compounds with a high potential to develop into anti-cancer drugs.
    Journal of Biological Chemistry 09/2015; DOI:10.1074/jbc.R115.689257
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    ABSTRACT: Prior studies in both budding yeast (Saccharomyces cerevisiae) and in human cells have established that septin protomers assemble into linear hetero-octameric rods with two-fold rotational symmetry. In mitotically-growing yeast cells, five septin subunits are expressed (Cdc3, Cdc10, Cdc11, Cdc12 and Shs1) and assemble into two types of rods that differ only in their terminal subunit: Cdc11-Cdc12-Cdc3-Cdc10-Cdc10-Cdc3-Cdc12-Cdc11 and Shs1-Cdc12-Cdc3-Cdc10-Cdc10-Cdc3-Cdc12-Shs1. EM analysis has shown that, under low-salt conditions, the Cdc11-capped rods polymerize end-to-end to form long paired filaments, whereas Shs1-capped rods form arcs, spirals and rings. To develop a facile method to study septin polymerization in vitro, we exploited our previous work where we generated septin complexes in which all endogenous cysteine (Cys) residues were eliminated by site-directed mutagenesis, except an introduced E294C mutation in Cdc11 in these experiments. Mixing samples of a preparation of such single-Cys containing Cdc11-capped rods that have been separately derivatized with organic dyes that serve as donor and acceptor, respectively, for FRET provided a spectroscopic method to monitor filament assembly mediated by Cdc11-Cdc11 interaction and to measure its affinity under specified conditions. Modifications of this same FRET scheme also allow us to assess whether Shs1-capped rods are capable of end-to-end association either with themselves or with Cdc11-capped rods. This FRET approach also was used to follow the binding to septin filaments of a septin-interacting protein, the type II myosin-binding protein Bni5.
    Journal of Biological Chemistry 09/2015; DOI:10.1074/jbc.M115.683128
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    ABSTRACT: Alzheimer's disease is the most severe neurodegenerative disease worldwide. In the past years, a plethora of small molecules interfering with amyloid-β (Aβ) aggregation have been suggested. However, their mode of interaction with amyloid fibers is not understood. Non-steroidal anti-inflammatory drugs (NSAIDs) are known γ-secretase modulators (GSMs). It has been suggested that NSAIDs are pleiotrophic and can interact with more than one pathomechanism. We present here a magic angle spinning (MAS) solid-state NMR study that shows that the NSAID sulindac sulfide interacts specifically with Alzheimer's disease Aβ fibrils. We find that sulindac sulfide does not induce drastic architectural changes in the fibrillar structure, but intercalates between the two β-strands of the amyloid fibril and binds to hydrophobic cavities, which are found consistently in all analyzed structures. The characteristic D23-K28 salt bridge is not affected upon interacting with sulindac sulfide. The primary binding site is located in the vicinity of residue G33, a residue involved in M35 oxidation. The results presented here could be useful in the search for pharmacologically active molecules which can potentially be employed as lead structures to guide the design of small molecules for the treatment of Alzheimer's disease.
    Journal of Biological Chemistry 09/2015; DOI:10.1074/jbc.M115.675215
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    ABSTRACT: Alzheimer's disease (AD) coincides with the formation of extracellular amyloid plaques composed of the amyloid-β (Aβ) peptide. Aβ is typically forty residues long (Aβ(1-40)) but can have variable C- and N- termini. Naturally occurring N-terminally truncated Aβ(11-40/42) is found in the cerebrospinal fluid and has a similar abundance to Aβ(1-42), constituting one fifth of the plaque load. Based on its specific N-terminal sequence we hypothesized that truncated Aβ(11-40/42) would have an elevated affinity for Cu(2+). Various spectroscopic techniques, complimented with transmission electron microscopy, were used to determine the properties of the Cu(2+)Aβ(11-40/42) interaction and how Cu(2+) influences amyloid fibre formation. We show, Cu(2+)Aβ(11-40) forms a tetragonal complex with a 34 ± 5 femtomolar dissociation constant at pH 7.4. This affinity is three orders of magnitude tighter than Cu(2+) binding to Aβ(1-40/42) and more than an order of magnitude tighter than that of serum albumin, the extracellular Cu(2+) transport protein. Furthermore, Aβ(11-40/42) forms fibres twice as fast as Aβ(1-40) with a very different morphology; forming bundles of very short amyloid rods. Substoichiometric Cu(2+) drastically perturbs Aβ(11-40/42) assembly, stabilizing much longer fibres. The very tight femtomolar affinity of Cu(2+) for Aβ(11-40/42) explains the high levels of Cu(2+) observed in AD plaques.
    Journal of Biological Chemistry 09/2015; DOI:10.1074/jbc.M115.684084