ALBERT

Description: Dielectronic recombination (DR) is an important process in hot plasma physics as well as in atomic structure and collision theory. This work reports the studies of the KLL DR resonance strengths of He-, Li-, Be-, B-, C-, N-, and O-like tungsten ions, through both experiment and calculation. The experimental resonance strengths were determined within uncertainty below 11% at the Shanghai electron beam ion trap by employing a fast electron beam-energy scanning technique. A fully relativistic configuration interaction method implemented in the flexible atomic code was employed to calculate DR process and also radiative recombination (RR). The consideration of the interference effect between DR and RR was revealed to be necessary to determine the resonance strength.

Description: Aims Distyly has been regarded as an adaptation to improve compatible pollination between two floral morphs with reciprocal herkogamy. The hypothesis that the different positions of anthers and stigmas within flowers as well as their reciprocal position between morphs, reduce the probability of self pollination raised by Darwin has been rarely tested. In this study, we measured stigmatic pollen loads in response to reduced reciprocal herkogamy in two Primula species. Methods To see whether reciprocal herkogamy can increase compatible and/or reduce incompatible pollen deposition, thus promoting compatible pollination, we shortened the distance between anthers and stigmas within the flowers by changing the position of the corolla tube, to which the anthers were fused, i.e. reduced herkogamy in natural populations of Primula secundiflora and P. poissonii and quantified stigmatic pollen loads in the field over 2 years. Important Findings In both species, stigmatic pollen loads were significantly higher in the long-styled (L-morph) than in the short-styled morph (S-morph) in both control and manipulated flowers, but percentage of compatible pollen in S-morph were higher. Flowers manipulated to halve the anther–stigma distance showed a similar pattern for 2 years: total pollen grain counts on stigmas did not differ significantly but compatible pollen grains in L- and S-morphs were significantly decreased in both species. The percentage of compatible pollen loads was decreased by 68.7% in P. secundiflora and 65.3% in P. poissonii in L-morphs, while it decreased by 30.6% and 2.9% in S-morphs, respectively. Our manipulation of the relative position of anthers and stigmas in the two distylous species indicated that a lower degree of herkogamy reduced compatible but incompatible pollen transfer was likely to increase. The higher proportion of compatible pollen in the S-morph than in the L-morph in the two Primula species could be attributed to the accessibility of two-level sexual organs, floral orientations and pollinator behaviors. This is a first attempt to manipulate intraflower herkogamy for understanding adaptation of heterostyly, shedding insights into how the reciprocal herkogamy promotes compatible pollination.

Description: Author(s): B. Tu, J. Xiao, K. Yao, Y. Shen, Y. Yang, D. Lu, W. X. Li, M. L. Qiu, X. Wang, C. Y. Chen, Y. Fu, B. Wei, C. Zheng, L. Y. Huang, B. H. Zhang, Y. J. Tang, R. Hutton, and Y. Zou Photon absorption spectroscopy is a powerful tool for uncovering the structure of atoms, molecules, and solids. Symmetric Lorentzian and asymmetric Fano line shapes are fundamental spectroscopic signatures related to the structural and dynamical properties. Recently, Ott et al. [ Science 340 , 716 (20... [Phys. Rev. A 91, 060502(R)] Published Mon Jun 22, 2015

Description: Author(s): B. Tu, J. Xiao, K. Yao, Y. Shen, Y. Yang, D. Lu, W. X. Li, M. L. Qiu, X. Wang, C. Y. Chen, Y. Fu, B. Wei, C. Zheng, L. Y. Huang, B. H. Zhang, Y. J. Tang, R. Hutton, and Y. Zou In this paper, we present experimental and theoretical studies on the interference between resonant and nonresonant photorecombinations for the main resonances of ground-state He-, Be-, B-, C-, N-, and O-like W ions. Experiments were done using a fast electron energy scanning technique at the upgrad… [Phys. Rev. A 93, 032707] Published Mon Mar 14, 2016

Description: The functions of G-protein-coupled receptors (GPCRs) are primarily mediated and modulated by three families of proteins: the heterotrimeric G proteins, the G-protein-coupled receptor kinases (GRKs) and the arrestins. G proteins mediate activation of second-messenger-generating enzymes and other effectors, GRKs phosphorylate activated receptors, and arrestins subsequently bind phosphorylated receptors and cause receptor desensitization. Arrestins activated by interaction with phosphorylated receptors can also mediate G-protein-independent signalling by serving as adaptors to link receptors to numerous signalling pathways. Despite their central role in regulation and signalling of GPCRs, a structural understanding of beta-arrestin activation and interaction with GPCRs is still lacking. Here we report the crystal structure of beta-arrestin-1 (also called arrestin-2) in complex with a fully phosphorylated 29-amino-acid carboxy-terminal peptide derived from the human V2 vasopressin receptor (V2Rpp). This peptide has previously been shown to functionally and conformationally activate beta-arrestin-1 (ref. 5). To capture this active conformation, we used a conformationally selective synthetic antibody fragment (Fab30) that recognizes the phosphopeptide-activated state of beta-arrestin-1. The structure of the beta-arrestin-1-V2Rpp-Fab30 complex shows marked conformational differences in beta-arrestin-1 compared to its inactive conformation. These include rotation of the amino- and carboxy-terminal domains relative to each other, and a major reorientation of the 'lariat loop' implicated in maintaining the inactive state of beta-arrestin-1. These results reveal, at high resolution, a receptor-interacting interface on beta-arrestin, and they indicate a potentially general molecular mechanism for activation of these multifunctional signalling and regulatory proteins.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3654799/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3654799/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Shukla, Arun K -- Manglik, Aashish -- Kruse, Andrew C -- Xiao, Kunhong -- Reis, Rosana I -- Tseng, Wei-Chou -- Staus, Dean P -- Hilger, Daniel -- Uysal, Serdar -- Huang, Li-Yin -- Paduch, Marcin -- Tripathi-Shukla, Prachi -- Koide, Akiko -- Koide, Shohei -- Weis, William I -- Kossiakoff, Anthony A -- Kobilka, Brian K -- Lefkowitz, Robert J -- GM072688/GM/NIGMS NIH HHS/ -- GM087519/GM/NIGMS NIH HHS/ -- HL 075443/HL/NHLBI NIH HHS/ -- HL16037/HL/NHLBI NIH HHS/ -- HL70631/HL/NHLBI NIH HHS/ -- NS028471/NS/NINDS NIH HHS/ -- P41 RR011823/RR/NCRR NIH HHS/ -- R01 HL016037/HL/NHLBI NIH HHS/ -- R01 HL070631/HL/NHLBI NIH HHS/ -- R01 NS028471/NS/NINDS NIH HHS/ -- U01 GM094588/GM/NIGMS NIH HHS/ -- U54 GM074946/GM/NIGMS NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2013 May 2;497(7447):137-41. doi: 10.1038/nature12120. Epub 2013 Apr 21.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/23604254" target="_blank"〉PubMed〈/a〉

Description: G-protein-coupled receptors (GPCRs) are critically regulated by beta-arrestins, which not only desensitize G-protein signalling but also initiate a G-protein-independent wave of signalling. A recent surge of structural data on a number of GPCRs, including the beta2 adrenergic receptor (beta2AR)-G-protein complex, has provided novel insights into the structural basis of receptor activation. However, complementary information has been lacking on the recruitment of beta-arrestins to activated GPCRs, primarily owing to challenges in obtaining stable receptor-beta-arrestin complexes for structural studies. Here we devised a strategy for forming and purifying a functional human beta2AR-beta-arrestin-1 complex that allowed us to visualize its architecture by single-particle negative-stain electron microscopy and to characterize the interactions between beta2AR and beta-arrestin 1 using hydrogen-deuterium exchange mass spectrometry (HDX-MS) and chemical crosslinking. Electron microscopy two-dimensional averages and three-dimensional reconstructions reveal bimodal binding of beta-arrestin 1 to the beta2AR, involving two separate sets of interactions, one with the phosphorylated carboxy terminus of the receptor and the other with its seven-transmembrane core. Areas of reduced HDX together with identification of crosslinked residues suggest engagement of the finger loop of beta-arrestin 1 with the seven-transmembrane core of the receptor. In contrast, focal areas of raised HDX levels indicate regions of increased dynamics in both the N and C domains of beta-arrestin 1 when coupled to the beta2AR. A molecular model of the beta2AR-beta-arrestin signalling complex was made by docking activated beta-arrestin 1 and beta2AR crystal structures into the electron microscopy map densities with constraints provided by HDX-MS and crosslinking, allowing us to obtain valuable insights into the overall architecture of a receptor-arrestin complex. The dynamic and structural information presented here provides a framework for better understanding the basis of GPCR regulation by arrestins.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4134437/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4134437/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Shukla, Arun K -- Westfield, Gerwin H -- Xiao, Kunhong -- Reis, Rosana I -- Huang, Li-Yin -- Tripathi-Shukla, Prachi -- Qian, Jiang -- Li, Sheng -- Blanc, Adi -- Oleskie, Austin N -- Dosey, Anne M -- Su, Min -- Liang, Cui-Rong -- Gu, Ling-Ling -- Shan, Jin-Ming -- Chen, Xin -- Hanna, Rachel -- Choi, Minjung -- Yao, Xiao Jie -- Klink, Bjoern U -- Kahsai, Alem W -- Sidhu, Sachdev S -- Koide, Shohei -- Penczek, Pawel A -- Kossiakoff, Anthony A -- Woods, Virgil L Jr -- Kobilka, Brian K -- Skiniotis, Georgios -- Lefkowitz, Robert J -- DK090165/DK/NIDDK NIH HHS/ -- GM072688/GM/NIGMS NIH HHS/ -- GM087519/GM/NIGMS NIH HHS/ -- GM60635/GM/NIGMS NIH HHS/ -- HL075443/HL/NHLBI NIH HHS/ -- HL16037/HL/NHLBI NIH HHS/ -- HL70631/HL/NHLBI NIH HHS/ -- MOP-93725/Canadian Institutes of Health Research/Canada -- NS028471/NS/NINDS NIH HHS/ -- R01 DK090165/DK/NIDDK NIH HHS/ -- R01 GM060635/GM/NIGMS NIH HHS/ -- R01 GM072688/GM/NIGMS NIH HHS/ -- R01 HL016037/HL/NHLBI NIH HHS/ -- R01 HL070631/HL/NHLBI NIH HHS/ -- R01 NS028471/NS/NINDS NIH HHS/ -- UL1 TR000430/TR/NCATS NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2014 Aug 14;512(7513):218-22. doi: 10.1038/nature13430. Epub 2014 Jun 22.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉1] Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710, USA [2] Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India. [3]. ; 1] Life Sciences Institute and Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA [2]. ; 1] Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710, USA [2]. ; Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710, USA. ; Department of Chemistry, University of California at San Diego, La Jolla, California 92093, USA. ; Life Sciences Institute and Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA. ; School of Pharmaceutical &Life Sciences, Changzhou University, Changzhou, Jiangsu 213164, China. ; Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario M5S 3E1, Canada. ; Department of Biochemistry, Duke University Medical Center, Durham, North Carolina 27710, USA. ; Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, Illinois 60637, USA. ; Department of Biochemistry and Molecular Biology, The University of Texas Medical School at Houston, Houston, Texas 77054, USA. ; 1] Department of Chemistry, University of California at San Diego, La Jolla, California 92093, USA [2]. ; Department of Molecular and Cellular Physiology, Stanford University School of Medicine, 279 Campus Drive, Stanford, California 94305, USA. ; 1] Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710, USA [2] Department of Biochemistry, Duke University Medical Center, Durham, North Carolina 27710, USA [3] Howard Hughes Medical Institute, Duke University Medical Center, Durham, North Carolina 27710, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25043026" target="_blank"〉PubMed〈/a〉

Description: Dicarbonyl/ l -xylulose reductase (DCXR), mainly catalysing the reduction of α-dicarbonyl compounds and l -xylulose, belongs to the short-chain dehydrogenase/reductase superfamily. Its enzyme activity can be inhibited by short-chain fatty acids. In this study, a novel DCXR inhibitor named (–)-epigallocatechin-3-gallate (EGCG) was reported. First, we overexpressed recombinant human DCXR in Escherichia coli , purified the enzyme by affinity chromatography and measured its activity. The inhibition effects of EGCG and its analogues on DCXR were determined subsequently, and EGCG showed the strongest inhibition with 50% inhibition concentration value of 78.8 μM. The surface plasmon resonance analysis also indicated that the equilibrium dissociation constant ( K D ) reached to 7.11 x 10 –8 M, which implied a high affinity between EGCG and DCXR. From enzyme kinetic analysis, EGCG acted as a mixed inhibitor against its forward and reverse substrates and the coenzyme, reduced nicotinamide adenine dinucleotide phosphate (NADPH). However, the inhibition is pH dependent. The molecular docking finally showed that EGCG formed several hydrogen bonds with the Thr190 residue of DCXR, and the model was further verified by site-directed mutagenesis. Therefore, EGCG is a potential inhibitor to human DCXR.

Description: Author(s): B. Tu, K. Yao, Y. Shen, Y. Yang, M. C. Li, T. H. Xu, Q. F. Lu, D. Lu, X. Wang, C. Y. Chen, Y. Fu, B. Wei, C. Zheng, L. Y. Huang, G. Xiong, J. M. Yang, B. H. Zhang, Y. J. Tang, R. Hutton, Y. Zou, and J. Xiao In this paper we report the L -shell dielectronic recombination measurement in highly charged 3 d n ions of tungsten by employing a fast electron beam-energy scanning technique at Shanghai EBIT. The studies of the LMM DR resonance strengths of Ar-like up to Mn-like tungsten were implemented through the... [Phys. Rev. A 96, 032705] Published Thu Sep 07, 2017

Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ehrenstein, G -- Huang, L Y -- New York, N.Y. -- Science. 1981 Dec 18;214(4527):1365-6.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7313696" target="_blank"〉PubMed〈/a〉

Description: Stereoisomers of the barbiturate anesthetic pentobarbital were applied to mouse spinal neurons growing in tissue culture. Intracellular recordings of neuronal membrane properties revealed that the (+) and (-) isomers caused direct changes in membrane potential and conductance on some but not all of the cells tested. The action of the (+) isomer was predominantly excitatory, whereas the (-) isomer produced predominantly inhibitory responses. The (-) isomer was considerably more effective in potentiating inhibitory responses to the transmitter gamma-aminobutyric acid. The results show that pentobarbital has multiple effects on neuronal excitability and demonstrate the presence of stereospecific sites of barbiturate action on central neurons.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Huang, L Y -- Barker, J L -- New York, N.Y. -- Science. 1980 Jan 11;207(4427):195-7.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7350656" target="_blank"〉PubMed〈/a〉