5 research outputs found
Diffusion of myosin V on microtubules
Organelle transport in eukaryotes employs both microtubule and actin tracks to deliver cargo effectively to their destinations, but the question of how the two systems cooperate is still largely unanswered. Recently, in vitro studies revealed that the actin-based processive motor myosin V also binds to, and diffuses along microtubules. This biophysical trick enables cells to exploit both tracks for the same transport process without switching motors. The detailed mechanisms underlying this behavior remain to be solved. By means of single molecule Total Internal Reflection Microscopy (TIRFM), we show here that electrostatic tethering between the positively charged loop 2 and the negatively charged C-terminal E-hooks of microtubules is dispensable. Furthermore, our data indicate that in addition to charge-charge interactions, other interaction forces such as non-ionic attraction might account for myosin V diffusion. These findings provide evidence for a novel way of myosin tethering to microtubules that does not interfere with other E-hook-dependent processes
Diffusion of Myosin V on Microtubules: A Fine-Tuned Interaction for Which E-Hooks Are Dispensable
Organelle transport in eukaryotes employs both microtubule and actin tracks to deliver cargo effectively to their destinations, but the question of how the two systems cooperate is still largely unanswered. Recently, in vitro studies revealed that the actin-based processive motor myosin V also binds to, and diffuses along microtubules. This biophysical trick enables cells to exploit both tracks for the same transport process without switching motors. The detailed mechanisms underlying this behavior remain to be solved. By means of single molecule Total Internal Reflection Microscopy (TIRFM), we show here that electrostatic tethering between the positively charged loop 2 and the negatively charged C-terminal E-hooks of microtubules is dispensable. Furthermore, our data indicate that in addition to charge-charge interactions, other interaction forces such as non-ionic attraction might account for myosin V diffusion. These findings provide evidence for a novel way of myosin tethering to microtubules that does not interfere with other E-hook-dependent processes
Multigram Synthesis of Isobutyl-β-<i>C</i>-galactoside as a Substitute of Isopropylthiogalactoside for Exogenous Gene Induction in Mammalian Cells
Herein we report that isobutyl-β-<i>C</i>-galactoside
(IBCG) is also a promising inducer of gene expression in mammalian
cells and report a new synthetic route to the compound that should
make obtaining the multigram quantities of material required for animal
studies more feasible. A convenient synthesis of IBCG, an inducer
of genes controlled by the <i>lac</i> operon system in bacterial
cells, was achieved in 5 steps from galactose in 81% overall yield
without any chromatographic separation steps. An optimized microwave-assisted
reaction at high concentration was key to making the <i>C-</i>glycosidic linkage. A Wittig reaction on a per<i>-O</i>-silylated rather than per-<i>O</i>-acetylated or -benzylated
substrate proved most effective in installing the final carbon atom