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Among a variety of solution-based approaches to fabricate anisotropic films of aligned carbon nanotubes (CNTs), we focus on the dielectrophoretic assembly method using AC electric fields in DNA-stabilized CNT suspensions. We demonstrate that a one-stop manufacturing system using electrode needles can draw anisotropic DNA-CNT hybrid films of 10 to 100 µm in size (i.e., free-standing DNA-CNT micro-cloths) from the remaining suspension into the atmosphere while maintaining structural order. It has been found that a maximal degree of polarization (ca. 40%) can be achieved by micro-cloths fabricated from a variety of DNA-CNT mixtures. Our results suggest that the one-stop method can impart biocompatibility to the downsized CNT films and that the DNA-stabilized CNT micro-cloths directly connected to an electrode could be useful for biofuel cells in terms of electron transfer and/or enzymatic activity.Electronic supplementary materialThe online version of this article (doi:10.1186/s11671-015-0817-3) contains supplementary material, which is available to authorized users.

Leucine-rich repeat kinase 2 (LRRK2), the major causative gene product of autosomal-dominant Parkinson's disease, is a protein kinase that phosphorylates a subset of Rab GTPases. Since pathogenic LRRK2 mutations increase its ability to phosphorylate Rab GTPases, elucidating the mechanisms of how Rab phosphorylation is regulated by LRRK2 is of great importance. We have previously reported that chloroquine-induced lysosomal stress facilitates LRRK2 phosphorylation of Rab10 to maintain lysosomal homeostasis. Here we reveal that Rab10 phosphorylation by LRRK2 is potently stimulated by treatment of cells with a set of lysosome stressors and clinically used lysosomotropic drugs. These agents commonly promoted the formation of LRRK2-coated enlarged lysosomes and extracellular release of lysosomal enzyme cathepsin B, the latter being dependent on LRRK2 kinase activity. In contrast to the increase in Rab10 phosphorylation, treatment with lysosomotropic drugs did not increase the enzymatic activity of LRRK2, as monitored by its autophosphorylation at Ser1292 residue, but rather enhanced the molecular proximity between LRRK2 and its substrate Rab GTPases on the cytosolic surface of lysosomes. Lysosomotropic drug-induced upregulation of Rab10 phosphorylation was likely a downstream event of Rab29 (Rab7L1)-mediated enzymatic activation of LRRK2. These results suggest a regulated process of Rab10 phosphorylation by LRRK2 that is associated with lysosomal overload stress, and provide insights into the novel strategies to halt the aberrant upregulation of LRRK2 kinase activity.

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