Category Archives: Proc Natl Acad Sci U S A

Global structural changes of an ion channel during its gating are followed by ion mobility mass spectrometry.

Global structural changes of an ion channel during its gating are followed by ion mobility mass spectrometry.

Proc Natl Acad Sci U S A. 2014 Nov 17;

Authors: Konijnenberg A, Yilmaz D, Ingólfsson HI, Dimitrova A, Marrink SJ, Li Z, Vénien-Bryan C, Sobott F, Koçer A

Abstract
Mechanosensitive ion channels are sensors probing membrane tension in all species; despite their importance and vital role in many cell functions, their gating mechanism remains to be elucidated. Here, we determined the conditions for releasing intact mechanosensitive channel of large conductance (MscL) proteins from their detergents in the gas phase using native ion mobility-mass spectrometry (IM-MS). By using IM-MS, we could detect the native mass of MscL from Escherichia coli, determine various global structural changes during its gating by measuring the rotationally averaged collision cross-sections, and show that it can function in the absence of a lipid bilayer. We could detect global conformational changes during MscL gating as small as 3%. Our findings will allow studying native structure of many other membrane proteins.

PMID: 25404294 [PubMed – as supplied by publisher]

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Relating influenza virus membrane fusion kinetics to stoichiometry of neutralizing antibodies at the single-particle level.

Relating influenza virus membrane fusion kinetics to stoichiometry of neutralizing antibodies at the single-particle level.
Proc Natl Acad Sci U S A. 2014 Nov 17;
Authors: Otterstrom JJ, Brandenburg B, Koldijk MH, Ju… Continue reading

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Cold and hunger induce diurnality in a nocturnal mammal.

Cold and hunger induce diurnality in a nocturnal mammal.
Proc Natl Acad Sci U S A. 2014 Oct 6;
Authors: van der Vinne V, Riede SJ, Gorter JA, Eijer WG, Sellix MT, Menaker M, Daan S, Pilorz V, Hut RA
Abstract
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A forager-herder trade-off, from broad-spectrum hunting to sheep management at Aşıklı Höyük, Turkey.

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A forager-herder trade-off, from broad-spectrum hunting to sheep management at Aşıklı Höyük, Turkey.

Proc Natl Acad Sci U S A. 2014 Jun 10;111(23):8404-9

Authors: Stiner MC, Buitenhuis H, Duru G, Kuhn SL, Mentzer SM, Munro ND, Pöllath N, Quade J, Tsartsidou G, Özbaşaran M

Abstract
Aşıklı Höyük is the earliest known preceramic Neolithic mound site in Central Anatolia. The oldest Levels, 4 and 5, spanning 8,200 to approximately 9,000 cal B.C., associate with round-house architecture and arguably represent the birth of the Pre-Pottery Neolithic in the region. Results from upper Level 4, reported here, indicate a broad meat diet that consisted of diverse wild ungulate and small animal species. The meat diet shifted gradually over just a few centuries to an exceptional emphasis on caprines (mainly sheep). Age-sex distributions of the caprines in upper Level 4 indicate selective manipulation by humans by or before 8,200 cal B.C. Primary dung accumulations between the structures demonstrate that ruminants were held captive inside the settlement at this time. Taken together, the zooarchaeological and geoarchaeological evidence demonstrate an emergent process of caprine management that was highly experimental in nature and oriented to quick returns. Stabling was one of the early mechanisms of caprine population isolation, a precondition to domestication.

PMID: 24778242 [PubMed – indexed for MEDLINE]

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Calcium entry into stereocilia drives adaptation of the mechanoelectrical transducer current of mammalian cochlear hair cells.

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Calcium entry into stereocilia drives adaptation of the mechanoelectrical transducer current of mammalian cochlear hair cells.

Proc Natl Acad Sci U S A….

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Chromosome instability induced by Mps1 and p53 mutation generates aggressive lymphomas exhibiting aneuploidy-induced stress.

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Chromosome instability induced by Mps1 and p53 mutation generates aggressive lymphomas exhibiting aneuploidy-induced stress.

Proc Natl Acad Sci U S A….

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Common genetic variants associated with cognitive performance identified using the proxy-phenotype method.

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Common genetic variants associated with cognitive performance identified using the proxy-phenotype method.

Proc Natl Acad Sci U S A. 2014 Sep 8;

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A critical reanalysis of the relationship between genomics and well-being.

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A critical reanalysis of the relationship between genomics and well-being.

Proc Natl Acad Sci U S A. 2014 Aug 25;

Authors: Brown NJ, MacDonald…

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Robust excitons inhabit soft supramolecular nanotubes.

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Robust excitons inhabit soft supramolecular nanotubes.
Proc Natl Acad Sci U S A. 2014 Aug 4;
Authors: Eisele DM, Arias DH, Fu X, Bloemsma EA, Steiner CP, Jensen RA, Rebentrost P, Eisele H, Tokmakoff A… Continue reading

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Calorie restriction does not elicit a robust extension of replicative lifespan in Saccharomyces cerevisiae.

Calorie restriction does not elicit a robust extension of replicative lifespan in Saccharomyces cerevisiae.

Proc Natl Acad Sci U S A. 2014 Jul 28;

Authors: Huberts DH, González J, Lee SS, Litsios A, Hubmann G, Wit EC, Heinemann M

Abstract
Calorie restriction (CR) is often described as the most robust manner to extend lifespan in a large variety of organisms. Hence, considerable research effort is directed toward understanding the mechanisms underlying CR, especially in the yeast Saccharomyces cerevisiae. However, the effect of CR on lifespan has never been systematically reviewed in this organism. Here, we performed a meta-analysis of replicative lifespan (RLS) data published in more than 40 different papers. Our analysis revealed that there is significant variation in the reported RLS data, which appears to be mainly due to the low number of cells analyzed per experiment. Furthermore, we found that the RLS measured at 2% (wt/vol) glucose in CR experiments is partly biased toward shorter lifespans compared with identical lifespan measurements from other studies. Excluding the 2% (wt/vol) glucose experiments from CR experiments, we determined that the average RLS of the yeast strains BY4741 and BY4742 is 25.9 buds at 2% (wt/vol) glucose and 30.2 buds under CR conditions. RLS measurements with a microfluidic dissection platform produced identical RLS data at 2% (wt/vol) glucose. However, CR conditions did not induce lifespan extension. As we excluded obvious methodological differences, such as temperature and medium, as causes, we conclude that subtle method-specific factors are crucial to induce lifespan extension under CR conditions in S. cerevisiae.

PMID: 25071164 [PubMed – as supplied by publisher]

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Bet-hedging during bacterial diauxic shift.

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Bet-hedging during bacterial diauxic shift.

Proc Natl Acad Sci U S A. 2014 May 20;111(20):7427-32

Authors: Solopova A, van Gestel J, Weissing…

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Significance of attitudinal experiments.

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Significance of attitudinal experiments.
Proc Natl Acad Sci U S A. 2014 May 13;111(19):E1938
Authors: van Hoorn A
PMID: 24715734 [PubMed – indexed for MEDLINE]

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Sparkling feather reflections of a bird-of-paradise explained by finite-difference time-domain modeling.

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Sparkling feather reflections of a bird-of-paradise explained by finite-difference time-domain modeling.
Proc Natl Acad Sci U S A. 2014 Mar 25;111(12):4363-8
Authors: Wilts BD, Michielsen K, De Raedt… Continue reading

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Small cationic antimicrobial peptides delocalize peripheral membrane proteins.

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Small cationic antimicrobial peptides delocalize peripheral membrane proteins.

Proc Natl Acad Sci U S A. 2014 Apr 8;111(14):E1409-18

Authors: Wenzel M, Chiriac AI, Otto A, Zweytick D, May C, Schumacher C, Gust R, Albada HB, Penkova M, Krämer U, Erdmann R, Metzler-Nolte N, Straus SK, Bremer E, Becher D, Brötz-Oesterhelt H, Sahl HG, Bandow JE

Abstract
Short antimicrobial peptides rich in arginine (R) and tryptophan (W) interact with membranes. To learn how this interaction leads to bacterial death, we characterized the effects of the minimal pharmacophore RWRWRW-NH2. A ruthenium-substituted derivative of this peptide localized to the membrane in vivo, and the peptide also integrated readily into mixed phospholipid bilayers that resemble Gram-positive membranes. Proteome and Western blot analyses showed that integration of the peptide caused delocalization of peripheral membrane proteins essential for respiration and cell-wall biosynthesis, limiting cellular energy and undermining cell-wall integrity. This delocalization phenomenon also was observed with the cyclic peptide gramicidin S, indicating the generality of the mechanism. Exogenous glutamate increases tolerance to the peptide, indicating that osmotic destabilization also contributes to antibacterial efficacy. Bacillus subtilis responds to peptide stress by releasing osmoprotective amino acids, in part via mechanosensitive channels. This response is triggered by membrane-targeting bacteriolytic peptides of different structural classes as well as by hypoosmotic conditions.

PMID: 24706874 [PubMed – indexed for MEDLINE]

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Single-molecule studies of polymerase dynamics and stoichiometry at the bacteriophage T7 replication machinery.

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Single-molecule studies of polymerase dynamics and stoichiometry at the bacteriophage T7 replication machinery.
Proc Natl Acad Sci U S A. 2014 Mar 18;111(11):4073-8
Authors: Geertsema HJ, Kulczyk AW,… Continue reading

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Efficient surveillance for healthcare-associated infections spreading between hospitals.

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Efficient surveillance for healthcare-associated infections spreading between hospitals.
Proc Natl Acad Sci U S A. 2014 Feb 11;111(6):2271-6
Authors: Ciccolini M, Donker T, Grundmann H, Bonten MJ, Wo… Continue reading

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“Critical slowing down in depression” is a great idea that still needs empirical proof.

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“Critical slowing down in depression” is a great idea that still needs empirical proof.

Proc Natl Acad Sci U S A. 2014 Mar 11;111(10):E878

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Reducing virulence of the human pathogen Burkholderia by altering the substrate specificity of the quorum-quenching acylase PvdQ.

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Reducing virulence of the human pathogen Burkholderia by altering the substrate specificity of the quorum-quenching acylase PvdQ.

Proc Natl Acad Sci U S…

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Highly correlated hedonic and eudaimonic well-being thwart genomic analysis.

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Highly correlated hedonic and eudaimonic well-being thwart genomic analysis.

Proc Natl Acad Sci U S A. 2013 Nov 5;110(45):E4183

Authors: Coyne JC

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Improved empirical tests of area-heterogeneity tradeoffs.

Improved empirical tests of area-heterogeneity tradeoffs.

Proc Natl Acad Sci U S A. 2013 Jun 10;

Authors: Carnicer J, Brotons L, Herrando S, Sol D

Abstract

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