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OPEN SCIENCE TAKES ON COVID-19 期刊论文
NATURE, 2020, 581 (7806) : 109-110
作者:  Mudelsee, Manfred;  Borngen, Michael;  Tetzlaff, Gerd;  Grunewald, Uwe
收藏  |  浏览/下载:11/0  |  提交时间:2020/07/03

Data sharing, open-source designs for medical equipment, and hobbyists are all being harnessed to combat COVID-19.


Data sharing, open-source designs for medical equipment, and hobbyists are all being harnessed to combat COVID-19.


  
Femtosecond-to-millisecond structural changes in a light-driven sodium pump 期刊论文
NATURE, 2020, 583 (7815) : 314-+
作者:  Moore, Luiza;  Leongamornlert, Daniel;  Coorens, Tim H. H.;  Sanders, Mathijs A.;  Ellis, Peter;  Dentro, Stefan C.;  Dawson, Kevin J.;  Butler, Tim;  Rahbari, Raheleh;  Mitchell, Thomas J.;  Maura, Francesco;  Nangalia, Jyoti;  Tarpey, Patrick S.;  Brunner, Simon F.;  Lee-Six, Henry;  Hooks, Yvette;  Moody, Sarah;  Mahbubani, Krishnaa T.;  Jimenez-Linan, Mercedes;  Brosens, Jan J.;  Iacobuzio-Donahue, Christine A.;  Martincorena, Inigo;  Saeb-Parsy, Kourosh;  Campbell, Peter J.;  Stratton, Michael R.
收藏  |  浏览/下载:17/0  |  提交时间:2020/07/03

Light-driven sodium pumps actively transport small cations across cellular membranes(1). These pumps are used by microorganisms to convert light into membrane potential and have become useful optogenetic tools with applications in neuroscience. Although the resting state structures of the prototypical sodium pump Krokinobacter eikastus rhodopsin 2 (KR2) have been solved(2,3), it is unclear how structural alterations overtime allow sodium to be translocated against a concentration gradient. Here, using the Swiss X-ray Free Electron Laser(4), we have collected serial crystallographic data at ten pump-probe delays from femtoseconds to milliseconds. High-resolution structural snapshots throughout the KR2 photocycle show how retinal isomerization is completed on the femtosecond timescale and changes the local structure of the binding pocket in the early nanoseconds. Subsequent rearrangements and deprotonation of the retinal Schiff base open an electrostatic gate in microseconds. Structural and spectroscopic data, in combination with quantum chemical calculations, indicate that a sodium ion bind stransiently close to the retinal within one millisecond. In the last structural intermediate, at 20 milliseconds after activation, we identified a potential second sodium-binding site close to the extracellular exit. These results provide direct molecular insight into the dynamics of active cation transport across biological membranes.


  
Molecular architecture of the human 17S U2 snRNP 期刊论文
NATURE, 2020, 583 (7815) : 310-+
作者:  Muench, David E.;  Olsson, Andre;  Ferchen, Kyle;  Pham, Giang;  Serafin, Rachel A.;  Chutipongtanate, Somchai;  Dwivedi, Pankaj;  Song, Baobao;  Hay, Stuart;  Chetal, Kashish;  Trump-Durbin, Lisa R.;  Mookerjee-Basu, Jayati;  Zhang, Kejian;  Yu, Jennifer C.
收藏  |  浏览/下载:18/0  |  提交时间:2020/07/03

The U2 small nuclear ribonucleoprotein (snRNP) has an essential role in the selection of the precursor mRNA branch-site adenosine, the nucleophile for the first step of splicing'  . Stable addition of U2 during early spliceosome formation requiresthe DEAD-box ATPase PRP5(2-7). Yeast U2 small nuclear RNA (snRNA) nucleotides that form base pairs with the branch site are initially sequestered in a branchpoint-interacting stem-loop (BSL)(8), but whether the human U2 snRNA folds in a similar manner is unknown. The U2 SF3B1 protein, a common mutational target in haematopoietic cancers(9), contains a HEAT domain (SF3B1(HEAT)) with an open conformation in isolated SF3b(10), but a closed conformation in spliceosomes(11), which is required for stable interaction between U2 and the branch site. Here we report a 3D cryo-electron microscopy structure ofthe human 17S U2 snRNP at a core resolution of 4.1 angstrom and combine it with protein crosslinking data to determine the molecular architecture of this snRNP. Our structure reveals that SF3B1(HEAT) interacts with PRP5 and TAT-SF1, and maintains its open conformation in U2 snRNP, and that U2 snRNA forms a BSL that is sandwiched between PRP5, TAT-SF1 and SF3B1(HEAT). Thus, substantial remodelling of the BSL and displacement of BSL-interacting proteins must occur to allow formation of the U2-branch-site helix. Our studies provide a structural explanation of why TAT-SF1 must be displaced before the stable addition of U2 to the spliceosome, and identify RNP rearrangements facilitated by PRP5 that are required for stable interaction between U2 and the branch site.


  
DNA clamp function of the monoubiquitinated Fanconi anaemia ID complex 期刊论文
NATURE, 2020, 580 (7802) : 278-+
作者:  Wu, Thomas D.;  39;Gorman, William E.
收藏  |  浏览/下载:8/0  |  提交时间:2020/07/03

The ID complex, involving the proteins FANCI and FANCD2, is required for the repair of DNA interstrand crosslinks (ICL) and related lesions(1). These proteins are mutated in Fanconi anaemia, a disease in which patients are predisposed to cancer. The Fanconi anaemia pathway of ICL repair is activated when a replication fork stalls at an ICL2  this triggers monoubiquitination of the ID complex, in which one ubiquitin molecule is conjugated to each of FANCI and FANCD2. Monoubiquitination of ID is essential for ICL repair by excision, translesion synthesis and homologous recombination  however, its function remains unknown(1,3). Here we report a cryo-electron microscopy structure of the monoubiquitinated human ID complex bound to DNA, and reveal that it forms a closed ring that encircles the DNA. By comparison with the structure of the non-ubiquitinated ID complex bound to ICL DNA-which we also report here-we show that monoubiquitination triggers a complete rearrangement of the open, trough-like ID structure through the ubiquitin of one protomer binding to the other protomer in a reciprocal fashion. These structures-together with biochemical data-indicate that the monoubiquitinated ID complex loses its preference for ICL and related branched DNA structures, and becomes a sliding DNA clamp that can coordinate the subsequent repair reactions. Our findings also reveal how monoubiquitination in general can induce an alternative protein structure with a new function.


Cryo-EM structures of the FANCI-FANCD2 complex bound to DNA reveal that monoubiquitination triggers structural changes that enable the complex to function as a sliding DNA clamp and coordinate the repair of DNA interstrand crosslinks.


  
Mass-spectrometry-based draft of the Arabidopsis proteome 期刊论文
NATURE, 2020
作者:  Vasanthakumar, Ajithkumar;  Chisanga, David;  Blume, Jonas;  Gloury, Renee;  Britt, Kara;  Henstridge, Darren C.;  Zhan, Yifan;  Torres, Santiago Valle;  Liene, Sebastian;  Collins, Nicholas;  Cao, Enyuan;  Sidwell, Tom;  Li, Chaoran;  Spallanzani, Raul German;  Liao, Yang;  Beavis, Paul A.;  Gebhardt, Thomas;  Trevaskis, Natalie;  Nutt, Stephen L.;  Zajac, Jeffrey D.;  Davey, Rachel A.;  Febbraio, Mark A.;  Mathis, Diane;  Shi, Wei;  Kallies, Axel
收藏  |  浏览/下载:37/0  |  提交时间:2020/07/03

Plants are essential for life and are extremely diverse organisms with unique molecular capabilities(1). Here we present a quantitative atlas of the transcriptomes, proteomes and phosphoproteomes of 30 tissues of the model plant Arabidopsis thaliana. Our analysis provides initial answers to how many genes exist as proteins (more than 18,000), where they are expressed, in which approximate quantities (a dynamic range of more than six orders of magnitude) and to what extent they are phosphorylated (over 43,000 sites). We present examples of how the data may be used, such as to discover proteins that are translated from short open-reading frames, to uncover sequence motifs that are involved in the regulation of protein production, and to identify tissue-specific protein complexes or phosphorylation-mediated signalling events. Interactive access to this resource for the plant community is provided by the ProteomicsDB and ATHENA databases, which include powerful bioinformatics tools to explore and characterize Arabidopsis proteins, their modifications and interactions.


A quantitative atlas of the transcriptomes, proteomes and phosphoproteomes of 30 tissues of the model plant Arabidopsis thaliana provides a valuable resource for plant research.


  
Synchrotron infrared spectroscopic evidence of the probable transition to metal hydrogen 期刊论文
NATURE, 2020, 577 (7792) : 631-+
作者:  Zhuang, Zhe;  Yu, Jin-Quan
收藏  |  浏览/下载:25/0  |  提交时间:2020/07/03

Hydrogen has been an essential element in the development of atomic, molecular and condensed matter physics(1). It is predicted that hydrogen should have a metal state(2)  however, understanding the properties of dense hydrogen has been more complex than originally thought, because under extreme conditions the electrons and protons are strongly coupled to each other and ultimately must both be treated as quantum particles(3,4). Therefore, how and when molecular solid hydrogen may transform into a metal is an open question. Although the quest for metal hydrogen has pushed major developments in modern experimental high-pressure physics, the various claims of its observation remain unconfirmed(5-7). Here a discontinuous change of the direct bandgap of hydrogen, from 0.6 electronvolts to below 0.1 electronvolts, is observed near 425 gigapascals. This result is most probably associated with the formation of the metallic state because the nucleus zero-point energy is larger than this lowest bandgap value. Pressures above 400 gigapascals are achieved with the recently developed toroidal diamond anvil cell(8), and the structural changes and electronic properties of dense solid hydrogen at 80 kelvin are probed using synchrotron infrared absorption spectroscopy. The continuous downward shifts of the vibron wavenumber and the direct bandgap with increased pressure point to the stability of phase-III hydrogen up to 425 gigapascals. The present data suggest that metallization of hydrogen proceeds within the molecular solid, in good agreement with previous calculations that capture many-body electronic correlations(9).


  
Palaeoclimate evidence of vulnerable permafrost during times of low sea ice 期刊论文
NATURE, 2020, 577 (7789) : 221-+
作者:  Vaks, A.;  Mason, A. J.;  Breitenbach, S. F. M.;  Kononov, A. M.;  Osinzev, A. V.;  Rosensaft, M.;  Borshevsky, A.;  Gutareva, O. S.;  Henderson, G. M.
收藏  |  浏览/下载:10/0  |  提交时间:2020/05/13

Climate change in the Arctic is occurring rapidly, and projections suggest the complete loss of summer sea ice by the middle of this century(1). The sensitivity of permanently frozen ground (permafrost) in the Northern Hemisphere to warming is less clear, and its long-term trends are harder to monitor than those of sea ice. Here we use palaeoclimate data to show that Siberian permafrost is robust to warming when Arctic sea ice is present, but vulnerable when it is absent. Uranium-lead chronology of carbonate deposits (speleothems) in a Siberian cave located at the southern edge of continuous permafrost reveals periods in which the overlying ground was not permanently frozen. The speleothem record starts 1.5 million years ago (Ma), a time when greater equator-to-pole heat transport led to a warmer Northern Hemisphere(2). The growth of the speleothems indicates that permafrost at the cave site was absent at that time, becoming more frequent from about 1.35 Ma, as the Northern Hemisphere cooled, and permanent after about 0.4 Ma. This history mirrors that of year-round sea ice in the Arctic Ocean, which was largely absent before about 0.4 Ma (ref.(3)), but continuously present since that date. The robustness of permafrost when sea ice is present, as well as the increased permafrost vulnerability when sea ice is absent, can be explained by changes in both heat and moisture transport. Reduced sea ice may contribute to warming of Arctic air(4-6), which can lead to warming far inland(7). Open Arctic waters also increase the source of moisture and increase autumn snowfall over Siberia, insulating the ground from low winter temperatures(8-10). These processes explain the relationship between an ice-free Arctic and permafrost thawing before 0.4 Ma. If these processes continue during modern climate change, future loss of summer Arctic sea ice will accelerate the thawing of Siberian permafrost.


  
Balancing Open Science and Data Privacy in the Water Sciences 期刊论文
WATER RESOURCES RESEARCH, 2019, 55 (7) : 5202-5211
作者:  Zipper, Samuel C.;  39;Donnell, Frances
收藏  |  浏览/下载:9/0  |  提交时间:2019/11/27
open science  data management  ethics  socio-hydrology  human subject research  Anthropocene  
Understanding uneven urban expansion with natural cities using open data 期刊论文
LANDSCAPE AND URBAN PLANNING, 2018, 177: 281-293
作者:  Long, Ying;  Zhai, Weixin;  Shen, Yao;  Ye, Xinyue
收藏  |  浏览/下载:6/0  |  提交时间:2019/04/09
Urban expansion  Social media  Head/tail division  New data  Open data  China  
Assessing the evolution of power sector carbon intensity in the United States 期刊论文
ENVIRONMENTAL RESEARCH LETTERS, 2018, 13 (6)
作者:  Schivley, Greg;  Azevedo, Ines;  Samaras, Constantine
收藏  |  浏览/下载:12/0  |  提交时间:2019/04/09
electricity  CO2 emissions  climate change policy  renewable portfolio standards  energy transitions  emissions intensity  open data