Hfsp Journal最新文献_第3页

Propagating waves separate two states of actin organization in living cells. 传播波将活细胞中肌动蛋白组织的两种状态分开。

Hfsp Journal Pub Date : 2009-12-01 Epub Date: 2009-11-30 DOI: 10.2976/1.3239407

Britta Schroth-Diez, Silke Gerwig, Mary Ecke, Reiner Hegerl, Stefan Diez, Günther Gerisch

{"title":"Propagating waves separate two states of actin organization in living cells.","authors":"Britta Schroth-Diez, Silke Gerwig, Mary Ecke, Reiner Hegerl, Stefan Diez, Günther Gerisch","doi":"10.2976/1.3239407","DOIUrl":"https://doi.org/10.2976/1.3239407","url":null,"abstract":"Propagating actin waves are dynamic supramolecular structures formed by the self-assembly of proteins within living cells. They are built from actin filaments together with single-headed myosin, the Arp23 complex, and coronin in a defined three-dimensional order. The function of these waves in structuring the cell cortex is studied on the substrate-attached surface of Dictyostelium cells by the use of total internal reflection fluorescence (TIRF) microscopy. Actin waves separate two areas of the cell cortex from each other, which are distinguished by the arrangement of actin filaments. The Arp23 complex dominates in the area enclosed by a wave, where it has the capacity of building dendritic structures, while the proteins prevailing in the external area, cortexillin I and myosin-II, bundle actin filaments and arrange them in antiparallel direction. Wave propagation is accompanied by transitions in the state of actin with a preferential period of 5 min. Wave generation is preceded by local fluctuations in actin assembly, some of the nuclei of polymerized actin emanating from clathrin-coated structures, others emerging independently. The dynamics of phase transitions has been analyzed to provide a basis for modeling the nonlinear interactions that produce spatio-temporal patterns in the actin system of living cells.","PeriodicalId":55056,"journal":{"name":"Hfsp Journal","volume":"3 6","pages":"412-27"},"PeriodicalIF":0.0,"publicationDate":"2009-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2976/1.3239407","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"29024338","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: 57

Early T-cell activation biophysics. 早期t细胞活化生物物理学。

Hfsp Journal Pub Date : 2009-12-01 Epub Date: 2009-11-10 DOI: 10.2976/1.3254098

Nelly Henry, Claire Hivroz

引用次数: 2

Kicked by Mos and tuned by MPF-the initiation of the MAPK cascade in Xenopus oocytes. 非洲爪蟾卵母细胞MAPK级联的启动由Mos踢腿和mpf调节。

Hfsp Journal Pub Date : 2009-12-01 Epub Date: 2009-12-18 DOI: 10.2976/1.3265771

C Russo, R Beaujois, J-F Bodart, R Blossey

引用次数: 8

Relax? Don't do it!-Linking presynaptic vesicle clustering with mechanical tension. 放松吗?别这么做!-连接突触前囊泡聚集与机械张力。

Hfsp Journal Pub Date : 2009-12-01 Epub Date: 2009-12-10 DOI: 10.2976/1.3260842

Peter Engerer, Stephan J Sigrist

{"title":"Relax? Don't do it!-Linking presynaptic vesicle clustering with mechanical tension.","authors":"Peter Engerer, Stephan J Sigrist","doi":"10.2976/1.3260842","DOIUrl":"https://doi.org/10.2976/1.3260842","url":null,"abstract":"The release of transmitter-filled vesicles from presynaptic terminals is a key step of neurotransmission. Prior to release, synaptic vesicles get clustered at a specialized patch of the presynaptic membrane, here referred to as the active zone. So far, mainly biochemical regulations at the active zone were regarded as decisive for synaptic vesicle clustering and release. However, using biophysical approaches, a recent paper [Siechen, et al. (2009). Proc. Natl. Acad. Sci. U.S.A. 106, 12611-12616] indicated also that the micromechanical regulations within axon and terminal could be crucial for proper vesicle clustering. The authors demonstrated that the synaptic vesicle accumulations vanished after axotomy but were restored after the application of physical tension. Furthermore, axons seem to be under an intrinsic tension, which could be perceived and tuned by an axon-internal tension sensing mechanism. Therefore, mechanical force could steer vesicle clustering and consequently synapse function. Here, we review this interdisciplinary study of Siechen, et al. [Proc. Natl. Acad. Sci. U.S.A. 106, 12611-12616 (2009)] and discuss the significance of cellular mechanics on synaptic function.","PeriodicalId":55056,"journal":{"name":"Hfsp Journal","volume":"3 6","pages":"367-72"},"PeriodicalIF":0.0,"publicationDate":"2009-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2976/1.3260842","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"29024334","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: 0

Drosophila morphogenesis: tissue force laws and the modeling of dorsal closure. 果蝇形态发生:组织力规律和背部闭合的建模。

Hfsp Journal Pub Date : 2009-12-01 Epub Date: 2009-12-15 DOI: 10.2976/1.3266062

Anita T Layton, Yusuke Toyama, Guo-Qiang Yang, Glenn S Edwards, Daniel P Kiehart, Stephanos Venakides

{"title":"Drosophila morphogenesis: tissue force laws and the modeling of dorsal closure.","authors":"Anita T Layton, Yusuke Toyama, Guo-Qiang Yang, Glenn S Edwards, Daniel P Kiehart, Stephanos Venakides","doi":"10.2976/1.3266062","DOIUrl":"https://doi.org/10.2976/1.3266062","url":null,"abstract":"Dorsal closure, a stage of Drosophila development, is a model system for cell sheet morphogenesis and wound healing. During closure, two flanks of epidermal tissue progressively advance to reduce the area of the eye-shaped opening in the dorsal surface, which contains amnioserosa tissue. To simulate the time evolution of the overall shape of the dorsal opening, we developed a mathematical model, in which contractility and elasticity are manifest in model force-producing elements that satisfy force-velocity relationships similar to muscle. The action of the elements is consistent with the force-producing behavior of actin and myosin in cells. The parameters that characterize the simulated embryos were optimized by reference to experimental observations on wild-type embryos and, to a lesser extent, on embryos whose amnioserosa was removed by laser surgery and on myospheroid mutant embryos. Simulations failed to reproduce the amnioserosa-removal protocol in either the elastic or the contractile limit, indicating that both elastic and contractile dynamics are essential components of the biological force-producing elements. We found it was necessary to actively upregulate forces to recapitulate both the double and single-canthus nick protocols, which did not participate in the optimization of parameters, suggesting the existence of additional key feedback mechanisms.","PeriodicalId":55056,"journal":{"name":"Hfsp Journal","volume":"3 6","pages":"441-60"},"PeriodicalIF":0.0,"publicationDate":"2009-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2976/1.3266062","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"29026502","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

Quantum physics meets biology. 量子物理学与生物学相遇。

Hfsp Journal Pub Date : 2009-12-01 Epub Date: 2009-11-09 DOI: 10.2976/1.3244985

Markus Arndt, Thomas Juffmann, Vlatko Vedral

引用次数: 0

How are nucleosomes disrupted during transcription elongation? 在转录延伸过程中核小体是如何被破坏的?

Hfsp Journal Pub Date : 2009-12-01 Epub Date: 2009-11-12 DOI: 10.2976/1.3249971

Jordanka Zlatanova, Jean-Marc Victor

引用次数: 15

Stochastic variation: from single cells to superorganisms. 随机变异:从单细胞到超级有机体。

Hfsp Journal Pub Date : 2009-12-01 Epub Date: 2009-10-09 DOI: 10.2976/1.3223356

Maria L Kilfoil, Paul Lasko, Ehab Abouheif