http://www.sciencedirect.com – Cellular automata can be designed that allow the simulation of a large variety of polymer problems including isolated polymers in dilute solution, polymers in high density melts and polymers embedded in media. The two-space algorithm is a particularly efficient algorithm for polymer simulation that is easy to implement and generalize on both conventional serial hardward and Cellular Automaton (CA) Machines. We describe the implementation of this algorithm and two applications: two dimensions (2-D) melts and polymer collapse. Read more »

http://www.pubmedcentral.nih.gov – The nuclear pore supports molecular communication between cytoplasm and nucleus in eukaryotic cells. Selective transport of proteins is mediated by soluble receptors, whose regulation by the small GTPase Ran leads to cargo accumulation in, or depletion from, the nucleus, i.e., nuclear import or nuclear export. We consider the operation of this transport system by a combined analytical and experimental approach. Provocative predictions of a simple model were tested using cell-free nuclei reconstituted in Xenopus egg extract, a system Read more »

http://www.ploscompbiol.org – The nuclear pore complex (NPC) is the gate to the nucleus. Recent determination of the configuration of proteins in the yeast NPC at ~5 nm resolution permits us to study the NPC global dynamics using coarse-grained structural models. We investigate these large-scale motions by using an extended elastic network model (ENM) formalism applied to several coarse-grained representations of the NPC. Two types of collective motions (global modes) are predicted by the ENMs to be intrinsically favored by the NPC architecture: global bending and extension/contraction from circular to elliptical shapes. Read more »

http://www.sciencemag.org – The nuclear pore complex regulates cargo transport between the cytoplasm and the nucleus. We set out to correlate the governing biochemical interactions to the nanoscopic responses of the phenylalanineglycine (FG)–rich nucleoporin domains, which are involved in attenuating or promoting cargo translocation. We found that binding interactions with the transport receptor karyopherin-b1 caused the FG domains of the human nucleoporin Nup153 to collapse into compact molecular conformations. Read more »

http://cardiovascres.oxfordjournals.org – Objective: Left ventricular assist devices (LVAD) are used to ‘bridge’ patients with end-stage heart failure to transplantation. After long-term LVAD support, ventricular function may partially recover, a process called ‘reverse remodeling’. As several kinase-mediated signal transduction pathways have been implicated in the development of cardiac hypertrophy and failure, we examined the activities of the Erks, MEKs, Akt, GSK-3β, p70S6K, JNKs and p38 under LVAD support as well as during single myocyte strain and whole heart stretch. Read more »

http://www.ncbi.nlm.nih.gov – Proper development of the skeleton in utero and during growth requires mechanical stimulation. Loading results in adaptive changes in bone that strengthen bone structure. Bone's adaptive response is regulated by the ability of resident bone cells to perceive and translate mechanical energy into a cascade of structural and biochemical changes within the cells a process known as mechanotransduction. Read more »

http://www.sciencedirect.com – Nuclear pore complexes are large aqueous channels that penetrate the nuclear envelope, thereby connecting the nuclear interior with the cytoplasm. Until recently, these macromolecular complexes were viewed as static structures, the only function of which was to control the molecular trafficking between the two compartments. It has now become evident that this simplistic scenario is inaccurate and that nuclear pore complexes are highly dynamic multiprotein assemblies involved in diverse cellular processes ranging from the organization of the cytoskeleton to gene expression. Read more »

http://www.sciencedirect.com – In eukaryotes, all macromolecules traffic between the nucleus and the cytoplasm through nuclear pore complexes (NPCs), which are among the largest supramolecular assemblies in cells. Although their composition in yeast and metazoa is well characterized, understanding how NPCs are assembled and form the pore through the double membrane of the nuclear envelope and how both processes are controlled still remains a challenge. Read more »

http://www.fasebj.org – Analysis of cellular mechanotransduc- tion, the mechanism by which cells convert mechanical signals into biochemical responses, has focused on identification of critical mechanosensitive molecules and cellular components. Stretch-activated ion chan- nels, caveolae, integrins, cadherins, growth factor re- ceptors, myosin motors, cytoskeletal filaments, nuclei, extracellular matrix, and numerous other structures and signaling molecules have all been shown to contrib- ute to the mechanotransduction response. Read more »

http://www3.interscience.wiley.com – Abstract Read more »