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Jin JJ, Lee M, Bai B, Sun YW, Qu J, Rahmadsyah, Alfiko Y, Lim CH, Suwanto A, Sugiharti M, Wong LS, Ye J, Chua NH, Yue GH
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Draft genome sequence of an elite Dura palm and whole-genome patterns of DNA variation in oil palm

DNA RESEARCH 2016 DEC; 23(6):527-533
Oil palm is the world's leading source of vegetable oil and fat. Dura, Pisifera and Tenera are three forms of oil palm. The genome sequence of Pisifera is available whereas the Dura form has not been sequenced yet. We sequenced the genome of one elite Dura palm, and re-sequenced 17 palm genomes. The assemble genome sequence of the elite Dura tree contained 10,971 scaffolds and was 1.701Gb in length, covering 94.49% of the oil palm genome. 36,105 genes were predicted. Re-sequencing of 17 additional palm trees identified 18.1 million SNPs. We found high genetic variation among palms from different geographical regions, but lower variation among Southeast Asian Dura and Pisifera palms. We mapped 10,000 SNPs on the linkage map of oil palm. In addition, high linkage disequilibrium (LD) was detected in the oil palms used in breeding populations of Southeast Asia, suggesting that LD mapping is likely to be practical in this important oil crop. Our data provide a valuable resource for accelerating genetic improvement and studying the mechanism underlying phenotypic variations of important oil palm traits.
Maishman L, Obado SO, Alsford S, Bart JM, Chen WM, Ratushny AV, Navarro M, Horn D, Aitchison JD, Chait BT, Rout MP, Field MC
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Co-dependence between trypanosome nuclear lamina components in nuclear stability and control of gene expression

NUCLEIC ACIDS RESEARCH 2016 DEC; 44(22):10554-10570
The nuclear lamina is a filamentous structure subtending the nuclear envelope and required for chromatin organization, transcriptional regulation and maintaining nuclear structure. The trypanosomatid coiled-coil NUP-1 protein is a lamina component functionally analogous to lamins, the major lamina proteins of metazoa. There is little evidence for shared ancestry, suggesting the presence of a distinct lamina system in trypanosomes. To find additional trypanosomatid lamina components we identified NUP-1 interacting proteins by affinity capture and mass-spectrometry. Multiple components of the nuclear pore complex (NPC) and a second coiled-coil protein, which we termed NUP-2, were found. NUP2 has a punctate distribution at the nuclear periphery throughout the cell cycle and is in close proximity to NUP-1, the NPCs and telomeric chromosomal regions. RNAi-mediated silencing of NUP-2 leads to severe proliferation defects, gross alterations to nuclear structure, chromosomal organization and nuclear envelope architecture. Further, transcription is altered at telomere-proximal variant surface glycoprotein (VSG) expression sites (ESs), suggesting a role in controlling ES expression, although NUP-2 silencing does not increase VSG switching. Transcriptome analysis suggests specific alterations to Pol I-dependent transcription. NUP-1 is mislocalized in NUP-2 knockdown cells and vice versa, implying that NUP-1 and NUP-2 form a co-dependent network and identifying NUP-2 as a second trypanosomatid nuclear lamina component.
Vastermark A, Driker A, Weng JW, Li XC, Wang JW, Saier MH
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The V-motifs facilitate the substrate capturing step of the PTS elevator mechanism

JOURNAL OF STRUCTURAL BIOLOGY 2016 DEC; 196(3):496-502
We propose that the alternative crystal forms of outward open UlaA (which are experimental, not simulated, and contain the substrate in the cavity) can be used to interpret/validate the MD results from MalT (the substrate capture step, which involves the mobile second TMSs of the V-motifs, TMSs 2 and 7). Since the crystal contacts are the same between the two alternative crystal forms of outward open UlaA, the striking biological differences noted, including rearranged hydrogen bonds and salt bridge coordination, are not attributable to crystal packing differences. Using transport assays, we identified G58 and G286 as essential for normal vitamin C transport, but the comparison of alternative crystal forms revealed that these residues to unhinge TMS movements from substrate-binding side chains, rendering the mid-TMS regions of homologous TMSs 2 and 7 relatively immobile. While the TMS that is involved in substrate binding in MalT is part of the homologous bundle that holds the two separate halves of the transport assembly (two proteins) together, an unequal effect of the two knockouts was observed for UlaA where both V-motifs are free from such dimer interface interactions. (C) 2016 Elsevier Inc. All rights reserved.
Sakmar TP, Huber T
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PHARMACOLOGY Inside-out receptor inhibition

NATURE 2016 DEC 15; 540(7633):344-345
Structures of two chemokine receptor proteins in complex with small molecules reveal a previously unknown binding pocket that could be a drug target for treating a range of diseases involving this receptor family. See Letters p.458 & p.462
Taylor's law (TL) asserts that the variance in a species' population density is a power-law function of its mean population density: log(variance)=a+bxlog(mean). TL is widely verified. We show here that empirical time series of density of the Hokkaido gray-sided vole, Myodes rufocanus, sampled 1962-1992 at 85 locations, satisfied temporal and spatial forms of TL. The slopes (b +/- standard error) of the temporal and spatial TL were estimated to be 1.613 +/- 0.141 and 1.430 +/- 0.132, respectively. A previously verified autoregressive Gompertz model of the dynamics of these populations generated time series of density which reproduced the form of temporal and spatial TLs, but with slopes that were significantly steeper than the slopes estimated from data. The density-dependent components of the Gompertz model were essential for the temporal TL. Adding to the Gompertz model assumptions that populations with higher mean density have reduced variance of density-independent perturbations and that density-independent perturbations are spatially correlated among populations yielded simulated time series that satisfactorily reproduced the slopes from data. The slopes (b +/- standard error) of the enhanced simulations were 1.619 +/- 0.199 for temporal TL and 1.575 +/- 0.204 for spatial TL.
Song RJ, Pace C, Seaman MS, Fang Q, Sun M, Andrews CD, Wu A, Padte NN, Ho DD
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Distinct HIV-1 Neutralization Potency Profiles of Ibalizumab-Based Bispecific Antibodies

JAIDS-JOURNAL OF ACQUIRED IMMUNE DEFICIENCY SYNDROMES 2016 DEC 1; 73(4):365-373
Background: Preexposure prophylaxis using antiretroviral agents has been shown to effectively prevent human immunodeficiency virus type 1 (HIV-1) acquisition in high-risk populations. However, the efficacy of these regimens is highly variable, which is thought to be largely due to the varying degrees of adherence to a daily intervention in the populations. Passive immunization using broadly neutralizing antibodies (bNAbs) against HIV-1, with their relatively long half-life and favorable safety profile, could provide an alternative to daily preexposure prophylaxis. However, most bNAbs have a limited breadth, only neutralizing 70%-90% of all HIV-1 strains. Methods: To overcome the problem of limited antiviral breadth, we proposed that targeting human CD4 and HIV-1 envelope proteins simultaneously may improve virus-neutralization breadth and potency. Therefore, we constructed bispecific antibodies (biAbs) using single-chain variable fragments of anti-gp120 bNAbs fused to ibalizumab (iMab), a humanized monoclonal antibody that binds human CD4, the primary receptor for HIV-1. Results: Some of our biAbs neutralized 100% of HIV-1 strains tested in vitro at clinically achievable concentrations. Distinct neutralization patterns were observed in this panel of biAbs. Those biAbs with specificity for the CD4-binding site on gp120 demonstrated 100% breadth, as well as slightly improved potency compared with iMab. In contrast, biAbs with specificity for the V1-V2 apex epitope or the V3-glycan epitope on gp120 demonstrated dramatically improved potency; some showed limited gain in neutralization breadth, whereas others (eg, PGT128-LM52 and 123-iMab) improved to 100% breadth. Conclusion: Our data suggest that this panel of iMab-based biAbs could be used to probe the parameters for potent HIV-1 neutralization. Moreover, a few of these biAbs warrant further studies and possibly clinical development.
Matheis F, Heppt MV, Graf SA, Duwell P, Kammerbauer C, Aigner A, Besch R, Berking C
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A Bifunctional Approach of Immunostimulation and uPAR Inhibition Shows Potent Antitumor Activity in Melanoma

JOURNAL OF INVESTIGATIVE DERMATOLOGY 2016 DEC; 136(12):2475-2484
Significant advancements of mutation-based targeted therapy and immune checkpoint blockade have been achieved in melanoma. Nevertheless, acquired resistance and nonresponders to therapy require different strategies. An innovative approach is presented here that is based on the combination of innate immune system activation and simultaneous targeting of the oncogene urokinase-type plasminogen activator receptor (uPAR). We generated two triphosphate-conjugated siRNAs targeting uPAR (ppp-uPAR) by in vitro transcription. Specific uPAR knockdown and simultaneous activation of the retinoic acid-inducible gene 1 (RIG-I) was shown in different human melanoma cells, fibroblasts, and melanocytes. The compounds induced massive apoptosis in melanoma cells, whereas fibroblasts and melanocytes were less sensitive. The effects were less pronounced when the IFN receptor was blocked. Treatment with ppp-uPAR led to accumulation of p53 and induction of RIG-Iedependent proapoptotic signaling. The apoptotic effects induced by ppp-uPAR were maintained in melanoma cell lines that had acquired double resistance to B-RAF and MEK/extracellular signal-regulated kinase inhibition. Systemic intraperitoneal application of ppp-uPAR in nude mice significantly reduced growth of human melanoma xenografts and elicited a systemic innate immune response with increased serum cytokine levels. Our data suggest that ppp-uPAR represents a therapeutically attractive compound that may help overcome the strong therapy resistance of melanoma.
Wimmer T, Srimathveeravalli G, Silk M, Monette S, Gutta N, Maybody M, Erinjery JP, Coleman JA, Solomon SB, Sofocleous CT
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Feasibility of a Modified Biopsy Needle for Irreversible Electroporation Ablation and Periprocedural Tissue Sampling

TECHNOLOGY IN CANCER RESEARCH & TREATMENT 2016 DEC; 15(6):749-758
Objectives: To test the feasibility of modified biopsy needles as probes for irreversible electroporation ablation and peripro-cedural biopsy. Methods: Core biopsy needles of 16-G/9-cm were customized to serve as experimental ablation probes. Computed tomography-guided percutaneous irreversible electroporation was performed in in vivo porcine kidneys with pairs of experimental (n = 10) or standard probes (n = 10) using a single parameter set (1667 V/cm, ninety 100 mu s pulses). Two biopsy samples were taken immediately following ablation using the experimental probes (n = 20). Ablation outcomes were compared using computed tomography, simulation, and histology. Biopsy and necropsy histology were compared. Results: Simulation-suggested ablations with experimental probes were smaller than that with standard electrodes (455.23 vs 543.16 mm(2)), although both exhibited similar shape. Computed tomography (standard: 556 +/- 61 mm(2), experimental: 515 +/- 67 mm(2); P = .25) and histology (standard: 313 +/- 77 mm(2), experimental: 275 +/- 75 mm(2); P +/- .29) indicated ablations with experimental probes were not significantly different from the standard. Histopathology indicated similar morphological changes in both groups. Biopsies from the ablation zone yielded at least 1 core with sufficient tissue for analysis (11 of the 20). Conclusions: A combined probe for irreversible electroporation ablation and periprocedural tissue sampling from the ablation zone is feasible. Ablation outcomes are comparable to those of standard electrodes.
Vucelja M
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Lifting-A nonreversible Markov chain Monte Carlo algorithm

AMERICAN JOURNAL OF PHYSICS 2016 DEC; 84(12):958-968
Markov chain Monte Carlo algorithms are invaluable tools for exploring stationary properties of physical systems, especially in situations where direct sampling is unfeasible. Common implementations of Monte Carlo algorithms employ reversible Markov chains. Reversible chains obey detailed balance and thus ensure that the system will eventually relax to equilibrium, though detailed balance is not necessary for convergence to equilibrium. We review nonreversible Markov chains, which violate detailed balance and yet still relax to a given target stationary distribution. In particular cases, nonreversible Markov chains are substantially better at sampling than the conventional reversible Markov chains with up to a square root improvement in the convergence time to the steady state. One kind of nonreversible Markov chain is constructed from the reversible ones by enlarging the state space and by modifying and adding extra transition rates to create non-reversible moves. Because of the augmentation of the state space, such chains are often referred to as lifted Markov Chains. We illustrate the use of lifted Markov chains for efficient sampling on several examples. The examples include sampling on a ring, sampling on a torus, the Ising model on a complete graph, and the one-dimensional Ising model. We also provide a pseudocode implementation, review related work, and discuss the applicability of such methods. (C) 2016 American Association of Physics Teachers.
Xiong XZ, Panchenko T, Yang S, Zhao S, Yan PQ, Zhang WH, Xie W, Li YY, Zhao YM, Allis CD, Li HT
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Selective recognition of Histone crotonylation by double PHD fingers of MOZ and DPF2

NATURE CHEMICAL BIOLOGY 2016 DEC; 12(12):1111-1118
Recognition of histone covalent modifications by 'reader' modules constitutes a major mechanism for epigenetic regulation. A recent upsurge of newly discovered histone lysine acylations, such as crotonylation (Kcr), butyrylation (Kbu), and propionylation (Kpr), greatly expands the coding potential of histone lysine modifications. Here we demonstrate that the histone-acetylation-binding double PHD finger (DPF) domains of human MOZ (also known as KAT6A) and DPF2 (also known as BAF45d) accommodate a wide range of histone lysine acylations with the strongest preference for Kcr. Crystal structures of the DPF domain of MOZ in complex with H3K14cr, H3K14bu, and H3K14pr peptides reveal that these non-acetyl acylations are anchored in a hydrophobic 'dead-end' pocket with selectivity for crotonylation arising from intimate encapsulation and an amide-sensing hydrogen bonding network. Immunofluorescence and chromatin immunoprecipitation (ChIP)-quantitative PCR (qPCR) showed that MOZ and H3K14cr colocalize in a DPF-dependent manner. Our studies call attention to a new regulatory mechanism centered on histone crotonylation readout by DPF family members.