http://phys.org/ en-us Phys.org internet news portal provides the latest news on science including: Physics, Nanotechnology, Life Sciences, Space Science, Earth Science, Environment, Health and Medicine. (Phys.org) —Molecular motor proteins inside the body, called kinesins, are a lot like the motor in your car. The molecular motors convert stored chemical energy into specific conformational changes, which lead to various movements in cells, analogous to the way a car engine converts the energy of gasoline combustion into torque generation, which leads to tires rotating on an axle. http://phys.org/news282898739.html Biology Tue, 19 Mar 2013 07:59:07 EST news282898739 Diverse cellular processes require many tiny force-generating motor proteins to work in a team. Paradoxically, nature often chooses the weak and inefficient dynein motor to generate large persistent forces inside cells. Here we show that a reason for this choice may be dynein's special ability to speed up or slow down depending on the load it senses. http://phys.org/news277643267.html Biology Thu, 17 Jan 2013 12:00:07 EST news277643267 High-speed atomic force microscopy (HS-AFM) is providing the means to produce dramatic footage of moving biomolecules, and scientists at Kanazawa University leading the field. http://phys.org/news276512530.html Nanotechnology Fri, 04 Jan 2013 09:02:28 EST news276512530 The motor protein myosin-V, which hauls molecular cargoes around cells by ratcheting along filaments of actin, switches between two different molecular mechanisms of movement depending on the environment. This finding by a research group led by Toshio Yanagida of the RIKEN Quantitative Biology Center, Osaka, and Osaka University, could form the basis for designing energy-saving artificial nano-motors. http://phys.org/news275302603.html Biology Fri, 21 Dec 2012 09:00:13 EST news275302603 The interior of an animal cell is like a small city, with factories—called organelles—dedicated to manufacturing, energy production, waste processing, and other life functions. A network of intercellular "highways," called microtubules, enables bio-molecular complexes, products, and other cargo to move speedily about the cell to keep this vital machinery humming. A new paper published online in the journal Proceedings of the National Academy of Sciences sheds new light on how cells manage to keep traffic flowing smoothly along this busy transportation network that is vital to the survival of cells and whose failure can lead to a variety of diseases, including Alzheimer's and cancer. http://phys.org/news274623393.html Biology Thu, 13 Dec 2012 12:16:39 EST news274623393 (Phys.org)—Physics researchers working at Brandeis University have created a gel that is capable of spontaneous movement. In their paper published in the journal Nature, the team describes how they created gel drops by adding protein tubes from cow brains and motor proteins from bacteria to a water solution – adding a polymer to the mix caused spontaneous movement to occur within the solution. http://phys.org/news271922999.html Chemistry Mon, 12 Nov 2012 06:20:01 EST news271922999 Cells can show a remarkable range of motility, creeping over substrates using a variety of pushes, pulls, stretches, and drags to get from A to B. This range of motion is achieved through the concerted efforts of motor proteins and structural complexes collectively known as the cytoskeleton. In addition to propulsion, however, cells also need to find footholds on surfaces in order to get the traction needed to advance or withdraw. Mobile single-celled organisms, such as the amoeba Dictyostelium, provide excellent living models for studying the molecular basis of such mechanisms, as they spend much of their lives solitary and on the crawl. http://phys.org/news267784630.html Biology Tue, 25 Sep 2012 09:37:20 EST news267784630 (Phys.org)—A new model system of the cellular skeletons of living cells is akin to a mini-laboratory designed to explore how the cells' functional structures assemble. A paper about to be published in European Physical Journal E by physicist Volker Schaller and his colleagues from the Technical University Munich, Germany, presents one hypothesis concerning self-organisation. It hinges on the findings that a homogeneous protein network, once subjected to stresses generated by molecular motors, compacts into highly condensed fibres. http://phys.org/news267271788.html Physics Wed, 19 Sep 2012 11:09:56 EST news267271788 Every second, around 25 million cell divisions take place in our bodies. This process is driven by microtubule filaments which continually grow and shrink. A new study shows how so-called motor proteins in the cytosol can control their dynamics. http://phys.org/news260452108.html Biology Mon, 02 Jul 2012 12:48:35 EST news260452108 Ulrich Technau from the University of Vienna has addressed the origin of musculature. His analysis reveals for the first time that some central components of muscles of higher animals are much older than previously assumed. These results, now published in the renowned journal Nature, indicate that muscle-like cell contraction originated already very early during animal evolution, while the specialization of basal muscle cell types, such as striated muscles, occurred only later and several times independently. http://phys.org/news260095103.html Biology Thu, 28 Jun 2012 09:38:36 EST news260095103 Kinesins assume a vital function in our cells: The tiny cargo transporters move important substances along lengthy protein fibers and ensure an effective transportation infrastructure. Biophysicists of the Technische Universitaet Muenchen and the Ludwig Maximillians Universitaet Muenchen have now discovered how some of these transporters can, like cars on a multi-lane motorway, change lanes. The researchers report on this hitherto unknown phenomenon in the current edition of the renowned journal Molecular Cell. http://phys.org/news254660373.html Biology Thu, 26 Apr 2012 12:00:02 EST news254660373 (PhysOrg.com) -- Building on the work of a previous team that found filaments made from actin, when combined with so called motor proteins, moved themselves into distinct patterns, a new team in Japan has found that combining different proteins results in the formation of far more elaborate patterns such as individual whorls and over time whole lattices. The team made up of a diverse group of researchers from across Japan, have published their findings in Nature. http://phys.org/news252141217.html Physics Wed, 28 Mar 2012 08:14:07 EST news252141217 Supplied with sufficient energy, a freight train would ride the rails as far as they go. But nature also knows systems whose dynamics suddenly turn into a kind of endless loop. Like in a hamster wheel, a train caught up in such a system would continue running, but without moving forward. Scientists from the Cluster of Excellence Nanosystems Initiative Munich have now succeeded in building a simple model system consisting of only three components to study the laws of such so-called absorbing states. http://phys.org/news240575318.html Biology Tue, 15 Nov 2011 11:00:01 EST news240575318 Interdisciplinary research between biology and physics aims to understand the cell and how it organizes internally. The mechanisms inside the cell are very complicated. LMU biophysicist Professor Erwin Frey, who is also a member of the Cluster of Excellence "Nanosystems Initiative Munich" (NIM) is working with his group on one particular issue involved in the cell's life. The professor for statistical and biological physics and his team, Louis Reese and Anna Melbinger, investigate the interplay of so-called molecular motors with the skeleton of the cell, the cytoskeleton. http://phys.org/news239886216.html Biology Mon, 07 Nov 2011 11:03:44 EST news239886216 (PhysOrg.com) -- An international team of scientists has shown how microtubules are interconnected into large networks. Like the poles of a tent, microtubules give shape to cells. By sliding microtubules along each other cells self-organize networks and relay forces that move chromosomes around during cell division. The team unravelled a mechanism that can stop the process of two microtubules sliding along each other before the two microtubules will lose their contact. http://phys.org/news234435127.html Biology Mon, 05 Sep 2011 09:52:34 EST news234435127 Every cell in the human body contains a complex system to transport essential cargoes such as proteins and membrane vesicles from one point to another. These tiny molecular motor proteins move at high speeds on miniature railways carrying components of the cell to their proper destinations. It is critical that these railways are neither too long nor too short, as that would cause a misdirection of the proteins being transported. But just how cells construct these transport railways to fit precisely inside the confines of individual cells is a complex question. http://phys.org/news234173387.html Biology Fri, 02 Sep 2011 09:10:15 EST news234173387 Basic biology textbooks may need a bit of revising now that biologists at UC San Diego have discovered a never-before-noticed component of our basic genetic material. http://phys.org/news232897527.html Biology Thu, 18 Aug 2011 15:30:01 EST news232897527 The transport system inside living cells is a well-oiled machine with tiny protein motors hauling chromosomes, neurotransmitters and other vital cargo around the cell. These molecular motors are responsible for a variety of critical transport jobs, but they are not always on the go. They can put themselves into "energy save mode" to conserve cellular fuel and, as a consequence, control what gets moved around the cell, and when. http://phys.org/news232292994.html Biology Thu, 11 Aug 2011 14:50:19 EST news232292994 Research scientists at the Ruhr University Bochum discovered a new enzyme, which gives decisive insights into protein import into specific cellular organelles (peroxisomes). In the Journal of Biological Chemistry, the team of Prof. Erdmann (Medical Faculty, Department of Systemic Biochemistry) reports that the enzyme Ubp15p collaborates with two other proteins to convert the protein transport machinery back into its initial condition after work has been completed. http://phys.org/news230813227.html Chemistry Mon, 25 Jul 2011 11:47:19 EST news230813227 (PhysOrg.com) -- Molecular "motors" are at the root of most biological movement. They propel cell components, whole cells, and even our muscles on command. Barbara Imperiali and a team from the Massachusetts Institute of Technology, the University of Virginia, and the National Institutes of Health have now provided the motor protein myosin with an “on switch” that is activated by light. As the scientists report in the journal Angewandte Chemie, this should make it possible to follow cellular processes that involve myosin in real time. http://phys.org/news224262028.html Chemistry Tue, 10 May 2011 16:30:01 EST news224262028 (PhysOrg.com) -- When unfolding a tent for the first time, you may wonder how the huge tarpaulin fits into a bag the size of a football. Biologists wonder about something similar: when a cell divides, the surface area of the cell membrane grows. Moreover, when molecules are brought from one organelle to another inside the cell, membrane-enclosed transport vesicles are formed. So that membranes can be made available quickly, they are stored within the cells in the form of nanotubes, tubular membrane structures – similarly to a tarpaulin that has been folded together. Researchers at the Max Planck Institute of Colloids and Interfaces in Potsdam have now discovered a mechanism used by cells to generate stable membrane nanotubes. http://phys.org/news219071817.html Nanotechnology Fri, 11 Mar 2011 13:17:31 EST news219071817 New research sheds light on the interaction between the semi-flexible protein tropomyosin and actin thin filaments. The study, published by Cell Press on February 15th in the Biophysical Journal, provides the first detailed atomic model of tropomyosin bound to actin and significantly advances the understanding of the dynamic relationship between these key cellular proteins. http://phys.org/news216997949.html Biology Tue, 15 Feb 2011 13:30:01 EST news216997949 (PhysOrg.com) -- When a cell is preparing to grow or replicate, it starts the way a monarch planning to expand his territory might: by identifying and marshaling the necessary resources, loading them onto the appropriate vehicles, and transporting them to the front line. http://phys.org/news215100841.html Biology Mon, 24 Jan 2011 14:14:25 EST news215100841 By tracking the flow of information in a cell preparing to split, Johns Hopkins scientists have identified a protein mechanism that coordinates and regulates the dynamics of shape change necessary for division of a single cell into two daughter cells. http://phys.org/news208193702.html Biology Fri, 05 Nov 2010 16:35:23 EST news208193702 A new study by Rice University bioengineers finds that the workhorse proteins that move cargo inside living cells behave like prima donnas. The protein, called kinesin, is a two-legged molecular machine. Rice's scientists invented tools that could measure the pulling power of kinesin both singly and in pairs, and they report this week in Biophysical Journal that kinesins don't work well together -- in part because they are so effective on their own. http://phys.org/news208176204.html Chemistry Fri, 05 Nov 2010 11:43:52 EST news208176204 For the casual observer it is fascinating to watch the orderly and seemingly choreographed motion of hundreds or even thousands of fish, birds or insects. However, the formation and the manifold motion patterns of such flocks raise numerous questions fundamental to the understanding of complex systems. http://phys.org/news202567291.html Physics Wed, 01 Sep 2010 13:42:59 EST news202567291 Scientists from the Florida campus of The Scripps Research Institute have discovered a mechanism that plays a critical role in the formation of long-term memory. The findings shed substantial new light on aspects of how memory is formed, and could lead to novel treatments for memory disorders. http://phys.org/news201961995.html Medicine & Health Wed, 25 Aug 2010 13:33:45 EST news201961995 Thanks to a single-molecule imaging technique developed by a University of Illinois professor, researchers have revealed the mechanisms of an important DNA-regulating enzyme. http://phys.org/news201527712.html Biology Fri, 20 Aug 2010 12:55:37 EST news201527712 Every single one of our cells contains so-called motor proteins that transport important substances from one location to another. However, very little is known about how exactly these transport processes occur. German biophysicists at the Technische Universitaet Muenchen (TUM) and Ludwig Maximilians Universitaet Muenchen (LMU) have now succeeded in explaining fundamental functions of a particularly interesting motor protein. They report their findings in the current issue of the Proceedings of the National Academy of Sciences. http://phys.org/news193670294.html Biology Fri, 21 May 2010 14:18:39 EST news193670294 (PhysOrg.com) -- University of Pennsylvania bioengineers have demonstrated that the cells that line blood vessels respond to mechanical forces -- the microscopic tugging and pulling on cellular structures -- by reinforcing and growing their connections, thus creating stronger adhesive interactions between neighboring cells. http://phys.org/news192967760.html Biology Thu, 13 May 2010 11:10:17 EST news192967760