Hfsp Journal最新文献_第5页

The local cell curvature guides pseudopodia towards chemoattractants. 局部细胞曲率引导假足向化学引诱剂方向运动。

Hfsp Journal Pub Date : 2009-08-01 Epub Date: 2009-08-07 DOI: 10.2976/1.3185725

Peter J M Van Haastert, Leonard Bosgraaf

引用次数: 27

Computational molecular biology approaches to ligand-target interactions. 配体-靶标相互作用的计算分子生物学方法。

Hfsp Journal Pub Date : 2009-08-01 Epub Date: 2009-03-10 DOI: 10.2976/1.3092784

Paola Lupieri, Chuong Ha Hung Nguyen, Zhaleh Ghaemi Bafghi, Alejandro Giorgetti, Paolo Carloni

引用次数: 12

Homeostatic competition drives tumor growth and metastasis nucleation. 稳态竞争驱动肿瘤生长和转移成核。

Hfsp Journal Pub Date : 2009-08-01 Epub Date: 2009-03-20 DOI: 10.2976/1.3086732

Markus Basan, Thomas Risler, Jean-François Joanny, Xavier Sastre-Garau, Jacques Prost

引用次数: 158

Forward locomotion of the nematode C. elegans is achieved through modulation of a single gait. 秀丽隐杆线虫的向前运动是通过调节单一步态实现的。

Hfsp Journal Pub Date : 2009-06-01 Epub Date: 2009-03-26 DOI: 10.2976/1.3082260

Stefano Berri, Jordan H Boyle, Manlio Tassieri, Ian A Hope, Netta Cohen

{"title":"Forward locomotion of the nematode C. elegans is achieved through modulation of a single gait.","authors":"Stefano Berri, Jordan H Boyle, Manlio Tassieri, Ian A Hope, Netta Cohen","doi":"10.2976/1.3082260","DOIUrl":"https://doi.org/10.2976/1.3082260","url":null,"abstract":"The ability of an animal to locomote through its environment depends crucially on the interplay between its active endogenous control and the physics of its interactions with the environment. The nematode worm Caenorhabditis elegans serves as an ideal model system for studying the respective roles of neural control and biomechanics, as well as the interaction between them. With only 302 neurons in a hard-wired neural circuit, the worm's apparent anatomical simplicity belies its behavioural complexity. Indeed, C. elegans exhibits a rich repertoire of complex behaviors, the majority of which are mediated by its adaptive undulatory locomotion. The conventional wisdom is that two kinematically distinct C. elegans locomotion behaviors-swimming in liquids and crawling on dense gel-like media-correspond to distinct locomotory gaits. Here we analyze the worm's motion through a series of different media and reveal a smooth transition from swimming to crawling, marked by a linear relationship between key locomotion metrics. These results point to a single locomotory gait, governed by the same underlying control mechanism. We further show that environmental forces play only a small role in determining the shape of the worm, placing conditions on the minimal pattern of internal forces driving locomotion.","PeriodicalId":55056,"journal":{"name":"Hfsp Journal","volume":"3 3","pages":"186-93"},"PeriodicalIF":0.0,"publicationDate":"2009-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2976/1.3082260","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"28333286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 137

RecQ helicases: multiple structures for multiple functions? RecQ解旋酶:多种功能的多种结构?

Hfsp Journal Pub Date : 2009-06-01 Epub Date: 2009-03-18 DOI: 10.2976/1.3079540

Alessandro Vindigni, Ian D Hickson

{"title":"RecQ helicases: multiple structures for multiple functions?","authors":"Alessandro Vindigni, Ian D Hickson","doi":"10.2976/1.3079540","DOIUrl":"https://doi.org/10.2976/1.3079540","url":null,"abstract":"Approximately 1% of the open reading frames in the human genome encode proteins that function as DNA or RNA helicases. These enzymes act in all aspects of nucleic acid metabolism where the complementary strands of DNA:DNA or DNA:RNA duplexes require to be transiently opened. However, they perform wider roles in nucleic acid metabolism due to their ability to couple the energy derived from hydrolysis of ATP to their unidirectional translocation along strands of DNARNA. In this way, helicases can displace proteins from DNARNA, drive the migration of DNA junctions (such as the Holliday junction recombination intermediate), or generate superhelical tension in nucleic acid duplexes. Here, we review a subgroup of DNA helicase enzymes, the RecQ family, that has attracted considerable interest in recent years due to their role not only in suppression of genome instability, but also in the avoidance of human disease. We focus particularly on the protein structural motifs and the multiple assembly states that characterize RecQ helicases and discuss novel biophysical techniques to study the different RecQ structures present in solution. We also speculate on the roles of the different domains and oligomeric forms in defining which DNA structures will represent substrates for RecQ helicase-mediated transactions.","PeriodicalId":55056,"journal":{"name":"Hfsp Journal","volume":"3 3","pages":"153-64"},"PeriodicalIF":0.0,"publicationDate":"2009-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2976/1.3079540","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"28538396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 61

Pak3 inhibits local actin filament formation to regulate global cell polarity. Pak3抑制局部肌动蛋白丝的形成以调节整体细胞极性。

Hfsp Journal Pub Date : 2009-06-01 Epub Date: 2009-04-10 DOI: 10.2976/1.3100548

Y Asano, A Jiménez-Dalmaroni, T B Liverpool, M C Marchetti, L Giomi, A Kiger, T Duke, B Baum

{"title":"Pak3 inhibits local actin filament formation to regulate global cell polarity.","authors":"Y Asano, A Jiménez-Dalmaroni, T B Liverpool, M C Marchetti, L Giomi, A Kiger, T Duke, B Baum","doi":"10.2976/1.3100548","DOIUrl":"https://doi.org/10.2976/1.3100548","url":null,"abstract":"Lamellipodia are broad actin-based structures that define the protruding edge of many motile animal cells. Here we identify a Drosophila homolog of the p21-activated kinases (Paks) as a novel inhibitor of Rac-mediated lamellipodial formation: Pak3 overexpression mimics a loss of Rac activity, while Pak3 RNAi-mediated silencing enhances lamellipodial dynamics. Strikingly, the depletion of Pak3 also polarizes the cellular distribution of actin filaments, is sufficient to induce nonmotile cells to migrate, and, in cells firmly attached to the substrate, gives rise to a wave of high actin filament density that encircles the cell periphery at a steady pace. To better understand these systems level phenomena, we developed a model of the cortical actin network as an active gel whose behavior is dominated by the rate of actin filament bundling and polymer synthesis. In the presence of filament treadmilling, this system generates a propagating density wave of actin filaments like that seen in Pak3 RNAi cells. This analysis reveals an intimate relationship between local regulation of actin filament dynamics and global cytoskeletal polarity, and suggests a role for negative regulators of lamellipodial formation, like Pak3, in the maintenance of a poised state, in which regulated directional cell movement can occur.","PeriodicalId":55056,"journal":{"name":"Hfsp Journal","volume":"3 3","pages":"194-203"},"PeriodicalIF":0.0,"publicationDate":"2009-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2976/1.3100548","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"28335026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 32

Copper trafficking in biology: an NMR approach. 生物学中的铜交易:核磁共振方法。

Hfsp Journal Pub Date : 2009-06-01 Epub Date: 2009-03-18 DOI: 10.2976/1.3078306

Lucia Banci, Ivano Bertini, Simone Ciofi-Baffoni

引用次数: 14

Self-organization in the developing nervous system: theoretical models. 发育中的神经系统的自组织:理论模型。

Hfsp Journal Pub Date : 2009-06-01 Epub Date: 2009-03-23 DOI: 10.2976/1.3079539

Stephen J Eglen, Julijana Gjorgjieva

引用次数: 13

The Tumbleweed: towards a synthetic proteinmotor. 风滚草:合成蛋白质马达。

Hfsp Journal Pub Date : 2009-06-01 Epub Date: 2009-04-28 DOI: 10.2976/1.3111282

Elizabeth H C Bromley, Nathan J Kuwada, Martin J Zuckermann, Roberta Donadini, Laleh Samii, Gerhard A Blab, Gregory J Gemmen, Benjamin J Lopez, Paul M G Curmi, Nancy R Forde, Derek N Woolfson, Heiner Linke

{"title":"The Tumbleweed: towards a synthetic proteinmotor.","authors":"Elizabeth H C Bromley, Nathan J Kuwada, Martin J Zuckermann, Roberta Donadini, Laleh Samii, Gerhard A Blab, Gregory J Gemmen, Benjamin J Lopez, Paul M G Curmi, Nancy R Forde, Derek N Woolfson, Heiner Linke","doi":"10.2976/1.3111282","DOIUrl":"https://doi.org/10.2976/1.3111282","url":null,"abstract":"Biomolecular motors have inspired the design and construction of artificial nanoscale motors and machines based on nucleic acids, small molecules, and inorganic nanostructures. However, the high degree of sophistication and efficiency of biomolecular motors, as well as their specific biological function, derives from the complexity afforded by protein building blocks. Here, we discuss a novel bottom-up approach to understanding biological motors by considering the construction of synthetic protein motors. Specifically, we present a design for a synthetic protein motor that moves along a linear track, dubbed the \"Tumbleweed.\" This concept uses three discrete ligand-dependent DNA-binding domains to perform cyclically ligand-gated, rectified diffusion along a synthesized DNA molecule. Here we describe how de novo peptide design and molecular biology could be used to produce the Tumbleweed, and we explore the fundamental motor operation of such a design using numerical simulations. The construction of this and more sophisticated protein motors is an exciting challenge that is likely to enhance our understanding of the structure-function relationship in biological motors.","PeriodicalId":55056,"journal":{"name":"Hfsp Journal","volume":"3 3","pages":"204-12"},"PeriodicalIF":0.0,"publicationDate":"2009-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2976/1.3111282","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"28335028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 34

Measuring accurately liquid and tissue surface tension with a compression plate tensiometer. 用压缩板张力计精确测量液体和组织表面张力。

Hfsp Journal Pub Date : 2009-06-01 Epub Date: 2009-04-28 DOI: 10.2976/1.3116822

Abbas Mgharbel, Hélène Delanoë-Ayari, Jean-Paul Rieu

{"title":"Measuring accurately liquid and tissue surface tension with a compression plate tensiometer.","authors":"Abbas Mgharbel, Hélène Delanoë-Ayari, Jean-Paul Rieu","doi":"10.2976/1.3116822","DOIUrl":"https://doi.org/10.2976/1.3116822","url":null,"abstract":"Apparent tissue surface tension allows the quantification of cell-cell cohesion and was reported to be a powerful indicator for the cellular rearrangements that take place during embryonic development or for cancer progression. The measurement is realized with a parallel compression plate tensiometer using the capillary laws. Although it was introduced more than a decade ago, it is based on various geometrical or physical approximations. Surprisingly, these approximations have never been tested. Using a novel tensiometer, we compare the two currently used methods to measure tissue surface tension and propose a third one, based on a local polynomial fit (LPF) of the profile of compressed droplets or cell aggregates. We show the importance of measuring the contact angle between the plate and the dropaggregate to obtain real accurate measurement of surface tension when applying existing methods. We can suspect that many reported values of surface tension are greatly affected because of not handling this parameter properly. We show then the benefit of using the newly introduced LPF method, which is not dependent on this parameter. These findings are confirmed by generating numerically compressed droplet profiles and testing the robustness and the sensitivity to errors of the different methods.","PeriodicalId":55056,"journal":{"name":"Hfsp Journal","volume":"3 3","pages":"213-21"},"PeriodicalIF":0.0,"publicationDate":"2009-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2976/1.3116822","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"28538397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 55