Intracellular transport along cytoskeletal filaments is often mediated by two teams of molecular motors that pull on the same cargo and move in opposite directions along the filaments. We have recently shown theoretically that this bidirectional transport can be understood as a stochastic tug-of-war between the two motor teams. Here, we further develop our theory to investigate the experimental...

Molecular motors are small, and, as a result, motor operation is dominated by high viscous friction and large thermal fluctuations from the surrounding fluid environment. The small size has made it very difficult to study the physical mechanisms of molecular motors. It is already difficult enough to see the motor itself, let alone to control the motor directly by applying an external force. In ...

BACKGROUND Export from the ER is an essential process driven by the COPII coat, which forms vesicles at ER exit sites (ERESs) to transport mature secretory proteins to the Golgi. Although the basic mechanism of COPII assembly is known, how COPII machinery is regulated to meet varying cellular secretory demands is unclear. RESULTS Here, we report a specialized COPII system that is actively rec...

Many eukaryotic secretory proteins are selected for export from the endoplasmic reticulum (ER) through their interaction with the Sec24p subunit of the coat protein II (COPII) coat. Three distinct cargo-binding sites on yeast Sec24p have been described by biochemical, genetic and structural studies. Each site recognizes a limited set of peptide motifs or a folded structural domain, however, the...

Membrane proteins are synthesized and folded in the endoplasmic reticulum (ER), and continue their path to their site of residence along the secretory pathway. The COPII system has been identified as a key player for selecting and directing the fate of membrane and secretory cargo proteins. Selection of cargo proteins within the COPII vesicles is achieved by cargo receptors. The cornichon cargo...

We consider the problem faced by an airline that is flying both passengers and cargo over a network of locations on a fixed periodic schedule. Bookings for many classes of cargo shipments between origin-destination pairs in this network are made in advance, but the weight and volume of aircraft capacity available for cargo as well as the exact weight and volume of each shipment are not known at...

background:the zinc-finger x linked (zfx) gene encodes a transcription factor that acts as a regulator of self-renewal of stem cells. due to the role of zfx in cell growth, understanding zfx protein-protein interactions helps to clarify its proper biological functions in signaling pathways. the aim of this study is to define zfx protein-protein interactions and the role of zfx in cell growth. m...

in this paper, a method based on binary-coded genetic algorithm is proposed to explore an optimization method, for obtaining an optimal elliptical tank. this optimization method enhances the rollover threshold of a tank vehicle, especially under partial filling conditions. minimizing the overturning moment imposed on the vehicle due to c.g. height of the liquid load, lateral acceleration and ca...

In this work, we explored theoretically the transport of organelles driven along microtubules by molecular motors of opposed polarities using a stochastic model that considers a Langevin dynamics for the cargo, independent cargo-motor linkers and stepping motion for the motors. It has been recently proposed that the stiffness of the motor plays an important role when multiple motors collectivel...

Clathrin-mediated endocytosis takes place through the recruitment of cargo molecules into a growing clathrin-coated pit (CCP). Despite the importance of this process to all mammalian cells, little is yet known about the interaction dynamics between cargo and CCPs. These interactions are difficult to study because CCPs display a large degree of lifetime heterogeneity and the interactions with ca...