53 research outputs found
How Molecular Motors Are Arranged on a Cargo Is Important for Vesicular Transport
The spatial organization of the cell depends upon intracellular trafficking of cargos hauled along microtubules and actin filaments by the molecular motor proteins kinesin, dynein, and myosin. Although much is known about how single motors function, there is significant evidence that cargos in vivo are carried by multiple motors. While some aspects of multiple motor function have received attention, how the cargo itself —and motor organization on the cargo—affects transport has not been considered. To address this, we have developed a three-dimensional Monte Carlo simulation of motors transporting a spherical cargo, subject to thermal fluctuations that produce both rotational and translational diffusion. We found that these fluctuations could exert a load on the motor(s), significantly decreasing the mean travel distance and velocity of large cargos, especially at large viscosities. In addition, the presence of the cargo could dramatically help the motor to bind productively to the microtubule: the relatively slow translational and rotational diffusion of moderately sized cargos gave the motors ample opportunity to bind to a microtubule before the motor/cargo ensemble diffuses out of range of that microtubule. For rapidly diffusing cargos, the probability of their binding to a microtubule was high if there were nearby microtubules that they could easily reach by translational diffusion. Our simulations found that one reason why motors may be approximately 100 nm long is to improve their ‘on’ rates when attached to comparably sized cargos. Finally, our results suggested that to efficiently regulate the number of active motors, motors should be clustered together rather than spread randomly over the surface of the cargo. While our simulation uses the specific parameters for kinesin, these effects result from generic properties of the motors, cargos, and filaments, so they should apply to other motors as well
Morphometry and acetylcholinesterase activity of the myenteric plexus of the wild mouse Calomys callosus
Effects of Chemical and Surgical Ganglionectomy on Electrical Activity of the Pineal Gland of Male Rats
Features of Seizures and Behavioral Changes Induced by Intrahippocampal Injection of Zinc Sulfate In the Rabbit: A New Experimental Model of Epilepsy
Age changes in vasomotor reflexes and ultrastructure of sympathetic neurons in rats after chemical desympathization
A histochemical study of the cephalic-cervical system of a gnathostomatid nematode,Echinocephalus sinensis, parasite of oysters and rays
Formes natives et globulaires de l'acetylcholinesterase dans la moelle epiniere et le cerveau de gymnote, Electrophorus electricus
Species differences in the distribution of adrenal free and sulfoconjugated catecholamines
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