A single-component, light-assisted uncaging switch for endoproteolytic release.

Proteases function as pivotal molecular switches, initiating numerous biological events. Notably, potyviral protease, derived from plant viruses, has emerged as a trusted proteolytic switch in synthetic biological circuits. To harness their capabilities, we have developed a single-component photocleavable switch, termed LAUNCHER (Light-Assisted UNcaging switCH for Endoproteolytic Release), by employing a circularly permutated tobacco etch virus protease and a blue-light-gated substrate, which are connected by fine-tuned intermodular linkers. As a single-component system, LAUNCHER exhibits a superior signal-to-noise ratio compared with multi-component systems, enabling precise and user-controllable release of payloads. This characteristic renders LAUNCHER highly suitable for diverse cellular applications, including transgene expression, tailored subcellular translocation and optochemogenetics. Additionally, the plug-and-play integration of LAUNCHER into existing synthetic circuits facilitates the enhancement of circuit performance. The demonstrated efficacy of LAUNCHER in improving existing circuitry underscores its significant potential for expanding its utilization in various applications.

Toxic effects of juvenile sablefish, Anoplopoma fimbria by ammonia exposure at different water temperature.

Juvenile sablefish, Anoplopoma fimbria (mean length 17.1±2.4cm, and mean weight 75.6±5.7g) were used to evaluate toxic effects on antioxidant systems, immune responses, and stress indicators by ammonia exposure (0, 0.25, 0.75, and 1.25mg/L) at different water temperature (12 and 17°C) in 1 and 2 months. In antioxidant responses, superoxide dismutase (SOD) and catalase (CAT) were significantly increased by ammonia exposure, whereas glutathione (GSH) was decreased. In immune responses, lysozyme and phagocytosis activity were significantly increased by ammonia exposure. In stress indicators, plasma glucose, heat shock protein 70 (HSP 70), and cortisol were significantly increased. At high water temperature (17°C), alterations by ammonia exposure were more distinctly. The results of this study indicated that ammonia exposure can induce toxic effects in the sablefish, and high water temperature can affect the ammonia exposure toxicity.

Application of a new cultivation technology, I-tip, for studying microbial diversity in freshwater sponges of Lake Baikal, Russia.

One of the fundamental methods for cultivating bacterial strains is conventional plating on solid media, but this method does not reveal the true diversity of the bacterial community. In this study, we develop a new technique and introduce a new device we term, I-tip. The I-tip was developed as an in situ cultivation device that allows microorganisms to enter and natural chemical compounds to diffuse, thereby permitting the microorganisms to grow utilizing chemical compounds in their natural environment. The new method was used to cultivate microorganisms from Baikalian sponges, and the results were compared with conventional plating as well as a pyrosequencing-based molecular survey. The I-tip method produced cultures of 34 species from five major phyla, Actinobacteria, Alphaproteobacteria, Betaproteobacteria, Firmicutes, and Gammaproteobacteria, 'missing' only two major phyla detected by pyrosequencing. Meanwhile, standard cultivation produced a smaller collection of 16 species from three major phyla, Betaproteobacteria, Firmicutes, and Gammaproteobacteria, failing to detect over half of the major phyla registered by pyrosequencing. We conclude that the I-tip method can narrow the gap between cultivated and uncultivated species, at least for some of the more challenging microbial communities such as those associated with animal hosts.

Peroxisome-localized hepatitis Bx protein increases the invasion property of hepatocellular carcinoma cells.

HBx acts as a multifunctional regulator that modulates various cellular responses, which can lead to development and progression of hepatocellular carcinoma (HCC). Here, we show that the HBx protein is also localized to peroxisomes, and this increases cellular reactive oxygen species (ROS) to levels that are higher than when HBx is localized to other organelles. The elevated ROS strongly activated nuclear factor (NF)-κB. In addition, the peroxisome-localized HBx increased the expressions of matrix metalloproteinases and decreased the expression of E-cadherin, which increased the invasive ability of HCC cells. Thus, a specific distribution of HBx to peroxisomes may contribute to HCC progression by increasing the invasive ability of HCC cells through elevation of the cellular ROS level.

Generation of continuous-wave single-frequency 1.5 W 378 nm radiation by frequency doubling of a Ti:sapphire laser.

We have generated continuous-wave single-frequency 1.5 W 378 nm radiation by frequency doubling a high-power Ti:sapphire laser in an external enhancement cavity. An LBO crystal that is Brewster-cut and antireflection coated on both ends is used for a long-term stable frequency doubling. By optimizing the input coupler's reflectivity, we could generate 1.5 W 378 nm radiation from a 5 W 756 nm Ti:sapphire laser. According to our knowledge, this is the highest CW frequency-doubled power of a Ti:sapphire laser.

External-cavity frequency doubling of a 5-W 756-nm injection-locked Ti:sapphire laser.

We have developed a 5-W 756-nm injection-locked Ti:sapphire laser and frequency-doubled it in an external enhancement cavity for the generation of watt-level 378-nm single-frequency radiation, which is essential for isotope-selective optical pumping of thallium atoms. With a lithium triborate (LBO) crystal in the enhancement cavity, 1.1 W at 378 nm was coupled out from the cavity. Such results are to our knowledge the highest powers of continuous-wave single-frequency radiation generated from a Ti:sapphire laser and its frequency doubling.