University System of Taiwan

About: University System of Taiwan is a education organization based out in Taipei, Taiwan. It is known for research contribution in the topics: Chemical vapor deposition & Noise figure. The organization has 83 authors who have published 55 publications receiving 1689 citations.

Identification and characterization of the CDK12/cyclin L1 complex involved in alternative splicing regulation.

Abstract: CrkRS is a Cdc2-related protein kinase that contains an arginine- and serine-rich (SR) domain, a characteristic of the SR protein family of splicing factors, and is proposed to be involved in RNA processing. However, whether it acts together with a cyclin and at which steps it may function to regulate RNA processing are not clear. Here, we report that CrkRS interacts with cyclin L1 and cyclin L2, and thus rename it as the long form of cyclin-dependent kinase 12 (CDK12(L)). A shorter isoform of CDK12, CDK12(S), that differs from CDK12(L) only at the carboxyl end, was also identified. Both isoforms associate with cyclin L1 through interactions mediated by the kinase domain and the cyclin domain, suggesting a bona fide CDK/cyclin partnership. Furthermore, CDK12 isoforms alter the splicing pattern of an E1a minigene, and the effect is potentiated by the cyclin domain of cyclin L1. When expression of CDK12 isoforms is perturbed by small interfering RNAs, a reversal of the splicing choices is observed. The activity of CDK12 on splicing is counteracted by SF2/ASF and SC35, but not by SRp40, SRp55, and SRp75. Together, our findings indicate that CDK12 and cyclin L1/L2 are cyclin-dependent kinase and cyclin partners and regulate alternative splicing.

Direct synthesis of suspended single-walled carbon nanotubes crossing plasma sharpened carbon nanofibre tips

Abstract: Herein we report a method for the direct synthesis of suspended single-walled carbon nanotubes (su-SWNTs) using carbon nanofibres (CNFs) as templates via a three-step fabrication process. Plasma-enhanced chemical vapour deposition was first employed to grow vertically aligned CNFs, which were then post-treated with an energetic argon plasma in the same reactor to yield structural transformation by sharpening tips and reducing embedded catalytic nanoparticles to favourable sizes, presumably below 10 nm. A thermal chemical vapour deposition process subsequently followed, for directly synthesizing SWNTs suspended across the tips or sidewalls of post-treated CNFs (PT-CNFs) with a span up to 10 µm. We also demonstrated that one can maximize the yield of su-SWNTs on the tips of PT-CNFs by optimizing the post-treatment conditions to provide a protective coating which suppresses the growth of SWNTs from sidewalls. In this approach, no further catalyst deposition is needed after the nanostructured PT-CNF template is formed. Thus, su-SWNTs can be selectively positioned on the tips of PT-CNFs with a clean substrate surface free from unwanted CNTs and with a suspension span not limited by the flow conditions of the carbon source gas. This method of fabricating su-SWNTs can be extended to position a single isolated SWNT for the purpose of either minimizing the environmental perturbation during SWNT characterization or enhancing the performance in nanodevice applications.